Advanced Manufacturing and Surface Technology

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Journal of Functional Biomaterials jfb	5.0	4.6	2010	16.6 Days	CHF 2700
Journal of Manufacturing and Materials Processing jmmp	3.3	5.1	2017	16.5 Days	CHF 1800
Lubricants lubricants	3.1	3.6	2013	14.6 Days	CHF 2600
Machines machines	2.1	3.0	2013	15.5 Days	CHF 2400
Materials materials	3.1	5.8	2008	13.9 Days	CHF 2600

14 pages, 3161 KiB

Open AccessArticle

Microstructure and Microhardness Research of Steel 304 After Forming Partially Regular Reliefs by Ball Burnishing Operation

by Stoyan Dimitrov Slavov, Diyan Minkov Dimitrov, Desislava Yordanova Mincheva, Volodymyr Dzyura, Pavlo Maruschak and Volodymyr Semehen

Materials 2025, 18(7), 1565; https://doi.org/10.3390/ma18071565 - 30 Mar 2025

Viewed by 266

Abstract

The influence of regular relief formation modes on the microhardness of the formed groove surface near the apex at the bottom of the groove has been studied. It has been established that the rate of plastic deformation, expressed as the feed rate of [...] Read more.

The influence of regular relief formation modes on the microhardness of the formed groove surface near the apex at the bottom of the groove has been studied. It has been established that the rate of plastic deformation, expressed as the feed rate of the deforming element, has a significant impact on the plastic deformation mechanism, and the microstructure of the formed subsurface layer, as well as on the microhardness of the groove surface. The influence of the type of partially regular reliefs on the degree of plastic deformation was also investigated. It was found that the third type of partially regular relief, which has the highest groove density, provides higher microhardness values than the first and second types. This is explained by the significantly greater density of these type of partially regular relief grooves, which exert a mutual strengthening effect on the surface during formation. The experimental study conducted enabled the derivation of regression equations describing the influence of the feed rate of the deforming element and the type of partially regular relief created on the surface microhardness beneath the lateral ridges and the bottoms of the plastically deformed traces. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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17 pages, 3618 KiB

Open AccessArticle

Alternative Real-Time Part Quality Monitoring Method by Using Stamping Force in Progressive Stamping Process

by Juras Skardžius and Justinas Gargasas

J. Manuf. Mater. Process. 2025, 9(4), 104; https://doi.org/10.3390/jmmp9040104 - 22 Mar 2025

Cited by 1 | Viewed by 315

Abstract

The manufacture of automotive parts using progressive stamping tools demands high precision and efficiency to meet industry standards. This research explores integrating quality monitoring techniques, focusing on load sensors and tonnage monitoring, to enhance the production process. Progressive tools, which perform multiple operations [...] Read more.

The manufacture of automotive parts using progressive stamping tools demands high precision and efficiency to meet industry standards. This research explores integrating quality monitoring techniques, focusing on load sensors and tonnage monitoring, to enhance the production process. Progressive tools, which perform multiple operations within a single press cycle, are critical for maintaining dimensional accuracy and minimizing defects. This research examines the correlation between real-time load sensor data and the tonnage applied during stamping, aiming to detect anomalies and deviations that may define part quality. By analyzing variations in tool loads and press tonnage, this research identifies patterns that allow the user to connect the applied force with the observed part quality and could help to determine potential issues such as instability of force or part dimensions, tool wear or improper alignment. The results of this research demonstrate that incorporating advanced monitoring systems into progressive stamping processes does not only improve part quality but also extends tool life and reduces downtime. The proposed approach provides a robust framework for ensuring reliability and efficiency in the production of automotive components, aligning with the industry demand for high-quality, cost-effective manufacturing solutions. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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7 pages, 1255 KiB

Open AccessCommunication

Effect of Electrode Surface Microstructuring on Electrochemical Biosensor Performance

by Amal Kabalan and Maliheh Azimi Roueini

Materials 2025, 18(7), 1390; https://doi.org/10.3390/ma18071390 - 21 Mar 2025

Viewed by 351

Abstract

Electrode surface microstructuring involves the engineering of the topographical features of an electrode to enhance its performance in electrochemical sensing applications. By creating controlled micro- or nano-scale patterns, the active surface area can significantly increase, which leads to improved electron transfer and enhanced [...] Read more.

Electrode surface microstructuring involves the engineering of the topographical features of an electrode to enhance its performance in electrochemical sensing applications. By creating controlled micro- or nano-scale patterns, the active surface area can significantly increase, which leads to improved electron transfer and enhanced sensitivity to target analytes in devices such as biosensors. Geometrical parameters such as diameter, height, pitch, and position of the patterns can be optimized to enhance sensor detection. This paper introduces an electrochemical biosensor designed to detect Moraxella catarrhalis, a respiratory pathogen affecting young children. This paper investigates the effects of the radius of micropillars on adsorption in the electrochemical biosensor using COMSOL Multiphysics (Version: 6.0). The model demonstrates that the rate of surface adsorption depends on the position of the micropillars on the electrode. The paper also presents the effects of analyte concentration on the detection current of the biosensor using Cottrell’s equation. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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14 pages, 5466 KiB

Open AccessArticle

Prediction of Residual Life of Rolling Bearings Based on Multi-Scale Improved Temporal Convolutional Network (MITCN) Model

by Keru Xia, Qi Li, Luyuan Han, Zhaohui Ren and Hengfa Luo

Machines 2025, 13(2), 137; https://doi.org/10.3390/machines13020137 - 11 Feb 2025

Cited by 1 | Viewed by 585

Abstract

The method based on convolution neural networks (CNNs) has been widely developed and applied to residual life prediction, and many excellent results have been achieved. However, CNN models can only learn feature information relative to size, and it is difficult to extract complex [...] Read more.

The method based on convolution neural networks (CNNs) has been widely developed and applied to residual life prediction, and many excellent results have been achieved. However, CNN models can only learn feature information relative to size, and it is difficult to extract complex time series features from data of long time series. In addition, the existing models still have some problems, such as capturing the correlation of each time series and generating a large amount of redundant information. In order to alleviate the above problems, this study proposes a residual life prediction method of rolling bearings based on a multi-scale improved temporal convolutional network (MITCN) model. It is used to solve problems such as the low accuracy of bearing life prediction and the difficulty of the temporal convolutional network (TCN) model to capture the correlation of each time series. The model adopts the framework of a time convolution network and has good ability to extract time series information. By introducing a multi-scale expanded causal convolution residual structure, improved temporal convolutional network (ITCN) modules with different expansion factors capture information on different time scales and combine soft threshold functions and channel attention mechanisms to adaptively generate thresholds and eliminate redundant information. Finally, the carbon border adjustment mechanism (CBAM) is an attention mechanism used to enhance useful features and suppress useless features, so as to realize the effective fusion of multi-scale features. The IEEE PHM 2012 challenge data set is hereby used to verify the proposed method, which can effectively solve the problem of the low prediction accuracy of the remaining life of bearings. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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12 pages, 3683 KiB

Open AccessArticle

Plasma Dielectric Etching with C₄H₂F₆ Isomers of Low Global-Warming Potential

by Minsu Choi, Youngseok Lee, Chulhee Cho, Wonnyoung Jeong, Inho Seong, Jami Md Ehsanul Haque, Byeongyeop Choi, Seonghyun Seo, Sijun Kim, Shinjae You and Geun Young Yeom

J. Manuf. Mater. Process. 2025, 9(2), 42; https://doi.org/10.3390/jmmp9020042 - 30 Jan 2025

Viewed by 877

Abstract

This paper presents the observed changes when replacing the widely used CHF₃ gas in semiconductor processing with two isomeric gases, C₄H₂F₆-iso and C₄H₂F₆-Z. This study investigates the etching process results [...] Read more.

This paper presents the observed changes when replacing the widely used CHF₃ gas in semiconductor processing with two isomeric gases, C₄H₂F₆-iso and C₄H₂F₆-Z. This study investigates the etching process results of SiO₂ and Si₃N₄ by varying the ratios of CHF₃, C₄H₂F₆ gases. The process outcomes were analyzed using ellipsometer and X-ray photoelectron spectroscopy, while plasma radical densities were examined through quadrupole mass spectrometry. The results are compared across five conditions, with substitution gas ratios ranging from 0% to 100%. The process results indicated that the selectivity increased at certain gas ratios. The diagnostic results provided the ratios of various etchants within the plasma. This research advances the development of alternative precursors designed to mitigate the effects of global warming. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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18 pages, 23143 KiB

Open AccessArticle

Effect of Al/Cu Ratio on Microstructure and High-Temperature Oxidation Resistance of Al_xCoCrCu_yFeNi High-Entropy Alloy Coatings

by Ling Zhou, Hongxi Liu, Qinghua Zhang, Jiazhu Liang, Yuanrun Peng, Xuanhong Hao, Chen Yang, Yaxia Liu and Yueyi Wang

J. Manuf. Mater. Process. 2025, 9(1), 13; https://doi.org/10.3390/jmmp9010013 - 5 Jan 2025

Cited by 2 | Viewed by 1249

Abstract

To improve high-temperature oxidation resistance for Ti6Al4V alloy, Al_xCoCrCu_yFeNi (x = 0, 0.3, 0.5, 0.7, 1.0; y = 1.0, 0.7, 0.5, 0.3, 0, x + y = 1.0) high-entropy alloy (HEA) coatings were prepared on the Ti6Al4V alloy substrate [...] Read more.

To improve high-temperature oxidation resistance for Ti6Al4V alloy, Al_xCoCrCu_yFeNi (x = 0, 0.3, 0.5, 0.7, 1.0; y = 1.0, 0.7, 0.5, 0.3, 0, x + y = 1.0) high-entropy alloy (HEA) coatings were prepared on the Ti6Al4V alloy substrate by a laser cladding technique. The results show that the coatings were mainly composed of FCC, BCC, and Ti-rich phases. Severe segregation of the Cu element occurred in the CoCrCuFeNi HEA coatings as a Cu-rich phase (FCC2). The Cu-rich phases decreased with a decreasing Cu content and completely disappeared until the Al content reached 1.0. The microhardnesses of the Cu_1.0, Cu_0.7Al_0.3, Cu_0.5Al_0.5, Cu_0.3Al_0.7, and Al_1.0 HEA coatings were 2.01, 2.06, 2.08, 2.09, and 2.11 times that of the substrate, and compared with those of a Ti6Al4V alloy substrate, the oxidation rates of the HEA coatings decreased by 55%, 51%, 47%, 42%, and 35%, respectively. The surface oxides of the five coatings were mainly composed of CuO, TiO₂, Fe₃O₄, Cr₂O₃, and Al₂O₃. The increase in the Al content promoted the generation of Al₂O₃ film and Cr₂O₃ on the surfaces of the coatings, which significantly improved the high-temperature antioxidant performance of the high-entropy alloy coatings for 50 h at 800 °C. When x = 1.0, the coating showed the best high-temperature antioxidant performance. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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16 pages, 4175 KiB

Open AccessArticle

Antioxidant Behavior of Carbon/Carbon Composites with Hot Dip Plating and Electroplating for Single-Crystal Furnaces

by Zuxing Qi, Chaofan Du, Guoying Bao, Shan Wang, Dedong Gao, Haixing Lin and Yan An

Materials 2024, 17(23), 5798; https://doi.org/10.3390/ma17235798 - 26 Nov 2024

Viewed by 587

Abstract

In the Czochralski single-crystal silicon manufacturing industry, single-crystal furnaces often experience corrosion from silicon vapor, which reduces their operational lifespan. However, the preparation of metal coatings on the surface of C/C composites is challenging due to their low coefficient of thermal expansion and [...] Read more.

In the Czochralski single-crystal silicon manufacturing industry, single-crystal furnaces often experience corrosion from silicon vapor, which reduces their operational lifespan. However, the preparation of metal coatings on the surface of C/C composites is challenging due to their low coefficient of thermal expansion and the intricate structure of carbon fibers. To address this issue and achieve high-quality alloy coatings, Ni-Al and Ni-Al/Si composite coatings are successfully prepared on the surface of C/C composites through a combination of electroplating and hot-dip plating, and their oxidation behavior at elevated temperatures is thoroughly investigated. The experimental results indicate that the Ni-Al composite coatings exhibit superior antioxidant properties compared to Ni coatings following thermal shock experiments, thereby significantly enhancing the antioxidant performance of C/C composites. This improvement is attributed to the preferential oxidation of surface aluminum, which forms a dense Al₂O₃ layer in aerobic and high-temperature environments, effectively preventing oxygen from reaching the underlying matrix. During the oxidation process, coating elements migrate outward along the concentration gradient, while oxygen molecules diffuse inward. Simultaneously, aluminum atoms diffuse inward, and Ni atoms diffuse outward, where they partially dissolve with oxygen. The inner coating’s Ni enhances the bonding of the coating by connecting the substrate to the outer layer. Meanwhile, the added Si in the Ni-Al/Si composite coating further improves the antioxidant properties of the coating. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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11 pages, 6390 KiB

Open AccessArticle

Development of Polymer Hydrophobic Surfaces Through Combined Laser Ablation and Hot Embossing Processes

by Esmaeil Ghadiri Zahrani, Amirmohmmad Fakharzadeh Jahromi and Bahman Azarhoushang

J. Manuf. Mater. Process. 2024, 8(6), 262; https://doi.org/10.3390/jmmp8060262 - 20 Nov 2024

Viewed by 1062

Abstract

The development of hydrophobicity on polymer surfaces in mass production is one of the most critical challenges in the plastic industry. This paper deals with a novel combined hot embossing process in which femtosecond laser ablation is utilized to texture the embossing stamps. [...] Read more.

The development of hydrophobicity on polymer surfaces in mass production is one of the most critical challenges in the plastic industry. This paper deals with a novel combined hot embossing process in which femtosecond laser ablation is utilized to texture the embossing stamps. By controlling the process temperature and axial forces, the laser textures were transferred to polymer surfaces, successfully resulting in hydrophobicity. Four different polymers, including ABS, PP, PA, and PC, along with two different laser textures, namely ball and pyramid, were tested. The laser and hot embossing parameters under which the textures were transferred to the polymers are introduced. The critical micro- and nano-features of the transferred textures that resulted in high hydrophobic contact angles are also discussed. The results indicate that PP and ABS have higher contact angles, respectively, while under the given parameters, PA and PC did not exhibit hydrophobic surfaces. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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19 pages, 8903 KiB

Open AccessArticle

Intercomparison of Indexable Cutting Inserts’ Wear Progress and Chip Formation During Machining Hardened Steel AISI 4337 and Austenitic Stainless Steel AISI 316 L

by Karel Šramhauser, Pavel Kraus, František Špalek, Pavel Černý, Jean de Dieu Marcel Ufitikirezi, Tomáš Zoubek, Miroslav Strob, Yevhen Kononets, Pavel Kříž and Vladimír Vochozka

Materials 2024, 17(22), 5418; https://doi.org/10.3390/ma17225418 - 6 Nov 2024

Cited by 1 | Viewed by 999

Abstract

This article deals with a mutual comparison of indexable cutting inserts of the CNMG 120408 type from two different manufacturers during the machining of hardened steel AISI 4337 and austenitic stainless steel AISI 316 L. The main goal is to analyse the different [...] Read more.

This article deals with a mutual comparison of indexable cutting inserts of the CNMG 120408 type from two different manufacturers during the machining of hardened steel AISI 4337 and austenitic stainless steel AISI 316 L. The main goal is to analyse the different wear processes depending on the difference in the manufacturer’s design and also depending on the properties of the different machined materials. The progress of the wear of the main spine of the tool, the types of wear and the service life of the cutting edge were monitored, with the achievement of the critical value VB_max = 300 µm being the standard. In addition to the wear of the inserts, the production of chips was monitored in terms of their shape, average size and number of chips per 100 g of chips produced. In order to understand the relationships arising from the obtained data, an SEM equipped with an elemental analyser was used to analyse the coating layers and the substrate of the unworn inserts and the types of wear and the intensity of the surface damage of the worn inserts. A several-fold difference in the lifetime of the cutting edge was found, both in terms of design and in terms of the selected machined material, while in both cases the cutting edge with Al₂O₃ and TiCN layers of half thickness achieved a better result in liveness. From the point of view of chip formation, very similar results in shape and average length were observed despite the different designs of chip breakers. Cutting inserts with half the thickness of the coating layers achieved longer cutting edge life in the non-primary material application compared to the target workpiece material. At the same time, it was observed that a thinner coating layer has a positive effect on chip formation in terms of its length and shape. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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17 pages, 4104 KiB

Open AccessArticle

Using the Ethaline Electropolishing Method on the Internal Surface of Additive Manufactured Tubes

by Dongyi Zou, Chaojiang Li, Yuxin Yang, Xin Jin, Shenggui Liu, Hongyi Zhang and Na Zhang

Materials 2024, 17(19), 4915; https://doi.org/10.3390/ma17194915 - 8 Oct 2024

Cited by 1 | Viewed by 1112

Abstract

Electropolishing is a widely used technique for polishing additive manufactured (AM) components, while complex internal surface polishing remains a challenge. In this study, we explore the use of ethaline as an electrolyte and investigate the effects of temperature, time, stirring speed, and voltage [...] Read more.

Electropolishing is a widely used technique for polishing additive manufactured (AM) components, while complex internal surface polishing remains a challenge. In this study, we explore the use of ethaline as an electrolyte and investigate the effects of temperature, time, stirring speed, and voltage on the electropolishing effectiveness for AM tubes without pre-treatment through orthogonal experiments. The optimal combination of these factors is then applied in further electropolishing experiments on straight tubes with large length-to-diameter ratios and an angled tube. Our results indicate that temperature has the most significant impact on internal surface electropolishing performance, and other factors’ effects are also analyzed. Ethaline can be a promising electrolyte for internal surface electropolishing of AM components because of its high viscosity, which is validated by flow field simulation of the hydrodynamic conditions inside the tubes. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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24 pages, 34297 KiB

Open AccessArticle

Control and Modelling of Laser Shock Peening without Coating (LSPwC) Texture of AISI 9310 Steel

by Ping Liu, Zhandiao Yang, Cenchao Xie, Fei Yang and Liucheng Zhou

Materials 2024, 17(19), 4776; https://doi.org/10.3390/ma17194776 - 28 Sep 2024

Viewed by 988

Abstract

LSPwC is an important development of Laser shock peening (LSP) technology, and surface texturing is an effective method to improve tribological properties. The combination of these is expected to innovate a new surface texturing technology with a strengthing effect, but no one has [...] Read more.

LSPwC is an important development of Laser shock peening (LSP) technology, and surface texturing is an effective method to improve tribological properties. The combination of these is expected to innovate a new surface texturing technology with a strengthing effect, but no one has attempted it. In this paper, a new LSPTwC technology combining them is innovatively proposed and validated on AISI 9310 steel, which is commonly used in helicopter transmission components for surface texturing. The LSPTwC surface was studied using an optical microscope, electron microscope, energy dispersive spectrometer, and so on. The results proved that LSPTwC is an effective texturing method of AISI 9310 steel, which modulates the texture and improves the properties, such as the microhardness increased by more than 10%. A model for calculating the texture and process parameters is also constructed on a statistical basis, and a modeling method for textured surfaces is proposed. It is verified that the calculation results and the constructed model are highly consistent with the test, with a diameter deviation <3% and depth deviation <4%. The above results can provide the experimental basis, process design method, and calculation model for single-point LSPwC texturing of AISI 9310 steel parts for helicopters, which have application value. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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19 pages, 8985 KiB

Open AccessArticle

Creation of Tool Coatings Based on Titanium Diboride for Highly Efficient Milling of Chromium–Nickel Alloys

by Sergey N. Grigoriev, Marina A. Volosova, Sergey V. Fedorov, Artem P. Mitrofanov, Vladimir D. Gurin and Anna A. Okunkova

J. Manuf. Mater. Process. 2024, 8(5), 210; https://doi.org/10.3390/jmmp8050210 - 26 Sep 2024

Viewed by 1568

Abstract

This paper describes the principles of obtaining wear-resistant coatings based on titanium diboride that are deposited on the cutting tool for use in the machining of chromium–nickel alloys. The spark plasma sintering of samples from the TiB₂/Ti powder composition was studied, [...] Read more.

This paper describes the principles of obtaining wear-resistant coatings based on titanium diboride that are deposited on the cutting tool for use in the machining of chromium–nickel alloys. The spark plasma sintering of samples from the TiB₂/Ti powder composition was studied, and the influence of sintering modes on the characteristics of the ceramic targets was analyzed. The regularities of the magnetron sputtering of sintered targets were revealed. The dependences of the physical and mechanical properties of coatings formed on hard alloy substrates on deposition conditions were established. The wear resistance of carbide samples with TiB₂-based coatings under friction-sliding conditions and coated carbide ball-end mills in milling Inconel 718 chromium–nickel alloy that is widely used in the industry was assessed. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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20 pages, 7710 KiB

Open AccessArticle

Synthesis of MnFe₂O₄ Spinel on Rusted Q235 Steel Surface and Its Corrosion Resistance Properties

by Bai-Ao Feng, Xu Miao and Ting-An Zhang

Materials 2024, 17(16), 4163; https://doi.org/10.3390/ma17164163 - 22 Aug 2024

Viewed by 975

Abstract

Corrosion of steel is an issue that cannot be ignored in contemporary society. Due to large-scale corrosion, it is urgent to develop a surface treatment process that enhances the corrosion resistance of steel, allowing for application in various scenarios as needed. This study [...] Read more.

Corrosion of steel is an issue that cannot be ignored in contemporary society. Due to large-scale corrosion, it is urgent to develop a surface treatment process that enhances the corrosion resistance of steel, allowing for application in various scenarios as needed. This study aims to investigate a novel surface treatment process to extend the service life of corroded Q235 steel, reduce its sensitivity to corrosion, and enable its use in multiple environments. This study employs the sol-gel method, using manganese nitrate solutions of varying concentrations to treat the surface of Q235 steel after different electrolysis times. The optimal conditions for precursor preparation were found to be a Mn²⁺ concentration of 0.1 mol/L and an electrolysis time of 2 h. Electrochemical tests using NaCl solutions of different concentrations revealed a significant reduction in the corrosion current for the composite coating based on Q235 steel treated with this method in NaCl solutions with wt.% = 1, 2, 3, 4, 5. Furthermore, the resistance to corrosion was strongest in the NaCl solution with a concentration of 1 wt.% where the corrosion current decreased from 24.8 µA/cm² to 6.79 µA/cm². Additionally, the coating was found to be diffusion-controlled in the early stages of the corrosion process and charge transfer-controlled in the later stages. The MnFe₂O₄ spinel coating demonstrated the greatest enhancement in corrosion resistance in the wt.% = 1 NaCl solution. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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14 pages, 30446 KiB

Open AccessArticle

Investigation of Electropolishing for High-Gradient 1.3 GHz and 3.9 GHz Niobium Cavities

by Yue Zong, Jinfang Chen, Dong Wang, Runzhi Xia, Jiani Wu, Zheng Wang, Shuai Xing, Xiaowei Wu, Xuhao He and Xiaohu Wang

Materials 2024, 17(13), 3207; https://doi.org/10.3390/ma17133207 - 1 Jul 2024

Viewed by 1351

Abstract

Electropolishing (EP) has become a standard procedure for treating the inner surfaces of superconducting radio-frequency (SRF) cavities composed of pure niobium. In this study, a new EP facility was employed for the surface treatment of both 1.3 GHz and 3.9 GHz single-cell cavities [...] Read more.

Electropolishing (EP) has become a standard procedure for treating the inner surfaces of superconducting radio-frequency (SRF) cavities composed of pure niobium. In this study, a new EP facility was employed for the surface treatment of both 1.3 GHz and 3.9 GHz single-cell cavities at the Wuxi Platform. The stable “cold EP” mode was successfully implemented on this newly designed EP facility. By integrating the cold EP process with a two-step baking approach, a maximum accelerating gradient exceeding 40 MV/m was achieved in 1.3 GHz single-cell cavities. Additionally, an update to this EP facility involved the design of a special cathode system for small-aperture structures, facilitating the cold EP process for 3.9 GHz single-cell cavities. Ultimately, a maximum accelerating gradient exceeding 25 MV/m was attained in the 3.9 GHz single-cell cavities after undergoing the cold EP treatment. The design and commissioning of the EP device, as well as the electropolishing and vertical test results of the single-cell cavities, will be detailed herein. These methods and experiences are also transferable to multi-cell cavities and elliptical cavities of other frequencies. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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22 pages, 7161 KiB

Open AccessArticle

Experiment and Simulation of Liquid Film Flow Driving Abrasive Particle Dispersion on the Surface of a Rotating Disk

by Qiong Fu, Weibin Shi, Nian Duan, Hui Huang and Yong Zhang

Machines 2024, 12(7), 441; https://doi.org/10.3390/machines12070441 - 27 Jun 2024

Cited by 1 | Viewed by 998

Abstract

Controlling the distribution of the abrasive grains on the surface of the grinding tools in an appropriate way is important for improving the quality of grinding processing and meeting the workpiece precision requirements. In the present study, a novel method for the orderly [...] Read more.

Controlling the distribution of the abrasive grains on the surface of the grinding tools in an appropriate way is important for improving the quality of grinding processing and meeting the workpiece precision requirements. In the present study, a novel method for the orderly arrangement of abrasive particles is proposed by using the liquid film flow on the surface of the rotating disk as the driving and controlling means for the uniform dispersion and position arrangement of abrasive particles. Computational fluid dynamics (CFD) simulations have been performed to clearly illustrate the trajectories of abrasive particles under the strong influence of liquid film flow on the rotating disk and reveal the effects of fluid flow, disk rotational motion, and the mixture viscosity on the particle distribution. A new abrasive grain arrangement device is designed and fabricated using this novel method. The operating parameters such as liquid volume flow rate, disk rotational speed, and liquid viscosity are adjusted to control the placement of abrasive grains on the surface of the grinding tool. An image processing tool is used to examine and analyze the arrangement results. The experimental results indicated that the application of the liquid film flow on a rotating disk to the abrasive grain arrangement can improve the arrangement of abrasive grains and get rid of the dependence on the template. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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12 pages, 7547 KiB

Open AccessArticle

Effect of CeO₂ Content on Microstructure and Wear Resistance of Laser-Cladded Ni-Based Composite Coating

by Bingqing Zhang, Wenqing Shi, Yiming Lin, Longwei Jiang, Lijun Wang and Kuanfang He

Lubricants 2024, 12(6), 227; https://doi.org/10.3390/lubricants12060227 - 19 Jun 2024

Cited by 4 | Viewed by 1455

Abstract

In order to improve the wear resistance of 45 steel, in this study, WC/Ni60 composite coatings with different CeO₂ additions (0, 1, 2, and 3 wt%) were prepared on 45 steel by the laser cladding technique; the experimental analysis was carried out [...] Read more.

In order to improve the wear resistance of 45 steel, in this study, WC/Ni60 composite coatings with different CeO₂ additions (0, 1, 2, and 3 wt%) were prepared on 45 steel by the laser cladding technique; the experimental analysis was carried out by means of scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), a Vickers hardness tester, and a friction and wear tester. The results show that CeO₂ had little effect on the phase composition of the coatings; however, with the increase in CeO₂ content, the CeO₂ played a key role in refining the grains of the coating, thus reducing the generation of cracks. In addition, CeO₂ could effectively strengthen the internal structure of the coating and improve its microhardness and wear resistance. Particularly noteworthy is the observed reduction in both the friction coefficient and mass loss of the coating when the CeO₂ addition reached 2%. This suggests an enhancement in the tribological performance of the coating at this concentration. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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21 pages, 4602 KiB

Open AccessReview

Effects of Cryogenic- and Cool-Assisted Burnishing on the Surface Integrity and Operating Behavior of Metal Components: A Review and Perspectives

by Jordan Maximov and Galya Duncheva

Machines 2024, 12(5), 312; https://doi.org/10.3390/machines12050312 - 2 May 2024

Cited by 4 | Viewed by 2217

Abstract

When placed under cryogenic temperatures (below −180 °C), metallic materials undergo structural changes that can improve their service life. This process, known as cryogenic treatment (CrT), has received extensive research attention over the past five decades. CrT can be applied as either an [...] Read more.

When placed under cryogenic temperatures (below −180 °C), metallic materials undergo structural changes that can improve their service life. This process, known as cryogenic treatment (CrT), has received extensive research attention over the past five decades. CrT can be applied as either an autonomous process (for steels and non-ferrous alloys, tool materials, and finished products) or as an assisting process for conventional metalworking. Cryogenic impacts and conventional machining or static surface cold working (SCW) can also be performed simultaneously in hybrid processes. The static SCW, known as burnishing, is a widely used environmentally friendly finishing process that achieves high-quality surfaces of metal components. The present review is dedicated to the portion of the hybrid processes in which burnishing under cryogenic conditions is carried out from the viewpoint of surface engineering, namely, finishing–surface integrity (SI)–operational behavior. Analyzes and summaries of the effects of cryogenic-assisted (CrA) burnishing on SI and the operational behavior of the investigated materials are made, and perspectives for future research are proposed. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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17 pages, 3630 KiB

Open AccessEditor’s ChoiceArticle

A New Hyaluronic Emulgel of Hesperetin for Topical Application—An In Vitro Evaluation

by Raquel Taléns-Visconti, Yousra Belarbi, Octavio Díez-Sales, Jesus Vicente de Julián-Ortiz, Ofelia Vila-Busó and Amparo Nácher

J. Funct. Biomater. 2024, 15(4), 89; https://doi.org/10.3390/jfb15040089 - 1 Apr 2024

Viewed by 2029

Abstract

The present study aimed to formulate and characterize a hesperetin formulation to achieve adequate deposition and retention of hesperetin in the epidermis as a target for some cosmetic/dermatological actions. To derive the final emulgel, various formulations incorporating different proportions of Polysorbate 80 and [...] Read more.

The present study aimed to formulate and characterize a hesperetin formulation to achieve adequate deposition and retention of hesperetin in the epidermis as a target for some cosmetic/dermatological actions. To derive the final emulgel, various formulations incorporating different proportions of Polysorbate 80 and hyaluronic acid underwent testing through a Box–Behnken experimental design. Nine formulations were created until the targeted emulgel properties were achieved. This systematic approach, following the principles of a design of experiment (DoE) methodology, adheres to a quality-by-design (QbD) paradigm, ensuring a robust and purposeful formulation and highlighting the commitment to a quality-driven design approach. The emulsions were developed using the phase inversion method, optimizing the emulgel with the incorporation of hyaluronic acid. Physically stable optimized emulgels were evaluated for their globule size, surface charge, viscosity, pH, electrical conductivity, and hesperetin content. These assays, along with the temperature swing test, were used to select the optimal formulation. It was characterized by a droplet size, d[4,3], of 4.02 μm, a Z-potential of −27.8 mV, an O/W sign, a pH of 5.2, and a creamy texture and proved to be stable for at least 2 months at room temperature. Additionally, in vitro release kinetics from the selected emulgel exhibited a sustained release profile of hesperetin. Skin assays revealed adequate retention of hesperetin in the human epidermis with minimum permeation. Altogether, these results corroborate the promising future of the proposed emulgel in cosmetic or dermatological use on healthy or diseased skin. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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15 pages, 4979 KiB

Open AccessArticle

Modelling and Optimization of Machined Surface Topography in Ball-End Milling Process

by Renwei Wang, Bin Zhao, Dingzhong Tan and Wenjie Wan

Materials 2024, 17(7), 1533; https://doi.org/10.3390/ma17071533 - 27 Mar 2024

Cited by 3 | Viewed by 1507

Abstract

In order to optimize machined surface topography, this paper presents a novel algorithm for simulating the surface topography and predicting the surface roughness of a ball-end milling process. First, a discrete workpiece model was developed using the Z-map method, and the swept surface [...] Read more.

In order to optimize machined surface topography, this paper presents a novel algorithm for simulating the surface topography and predicting the surface roughness of a ball-end milling process. First, a discrete workpiece model was developed using the Z-map method, and the swept surface of a cutter edge was represented using triangular approximation. The workpiece surface was updated (i.e., material removal process) using the intersection between the vertical reference line and the triangular facet under a cutting judgement. Second, the proposed algorithm was verified by comparing the simulated 3D surface topography as well as 2D surface profile and average roughness (Sa) with experimental measurements. Then, numerical simulation examples planed by the Box–Behnken design methods were carried out to investigate the Sa in the ball-end milling operation. The correlations of S_a and cutting parameters were represented by a response surface reduced quadratic model based on the ANOVA results. Finally, the feed per tooth, radial depth of cut, and tilt and lead angles were optimized for improving the machining efficiency under the Sa constraints. This study presents an effective method for simulating surface topography and predicting the Sa to optimize the cutting parameters during ball-end milling process. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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20 pages, 18651 KiB

Open AccessArticle

The Influence of Flame Exposure and Solid Particle Erosion on Tensile Strength of CFRP Substrate with Manufactured Protective Coating

by Przemysław Golewski and Michał Budka

Materials 2024, 17(5), 1203; https://doi.org/10.3390/ma17051203 - 5 Mar 2024

Cited by 1 | Viewed by 1460

Abstract

This paper presents the results of laboratory tests for new materials made of a carbon fibre-reinforced polymer (CFRP) composite with a single-sided protective coating. The protective coatings were made of five different powders—Al₂O₃, aluminium, quartz sand, crystalline silica and [...] Read more.

This paper presents the results of laboratory tests for new materials made of a carbon fibre-reinforced polymer (CFRP) composite with a single-sided protective coating. The protective coatings were made of five different powders—Al₂O₃, aluminium, quartz sand, crystalline silica and copper—laminated in a single process during curing of the prepreg substrate with an epoxy matrix. The specimens were subjected to flame exposure and solid particle erosion tests, followed by uniaxial tensile tests. A digital image correlation (DIC) system was used to observe the damage location and deformation of the specimens. All coatings subjected to solid particle erosion allowed an increase in tensile failure force ranging from 5% to 31% compared to reference specimens made of purely CFRP. When exposed to flame, only three of the five materials tested, Al₂O₃, aluminium, quartz sand, could be used to protect the surface, which allowed an increase in tensile failure force of 5.6%. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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16 pages, 5470 KiB

Open AccessArticle

Design and Study of Machine Tools for the Fly-Cutting of Ceramic-Copper Substrates

by Chupeng Zhang, Jiazheng Sun, Jia Zhou and Xiao Chen

Materials 2024, 17(5), 1111; https://doi.org/10.3390/ma17051111 - 28 Feb 2024

Viewed by 1361

Abstract

Ceramic-copper substrates, as high-power, load-bearing components, are widely used in new energy vehicles, electric locomotives, high-energy lasers, integrated circuits, and other fields. The service length will depend on the substrate’s copper-coated surface quality, which frequently achieved by utilising an abrasive strip polishing procedure [...] Read more.

Ceramic-copper substrates, as high-power, load-bearing components, are widely used in new energy vehicles, electric locomotives, high-energy lasers, integrated circuits, and other fields. The service length will depend on the substrate’s copper-coated surface quality, which frequently achieved by utilising an abrasive strip polishing procedure on the substrate’s copper-coated surface. Precision diamond fly-cutting processing machine tools were made because of the low processing accuracy and inability to match the production line’s efficiency. An analysis of the fly-cutting machining principle and the structural makeup of the ceramic-copper substrate is the first step in creating a roughness prediction model based on a tool tip trajectory. This model demonstrates that a shift in the tool tip trajectory due to spindle runout error directly impacts the machined surface’s roughness. The device’s structural optimisation design is derived from the above analyses and implemented using finite element software. Modal and harmonic response analysis validated the machine’s gantry symmetrical structural layout, a parametric variable optimisation design optimised the machine tool’s overall dimensions, and simulation validated the fly-cutterring’s constituent parts. Enhancing the machine tool’s stability and motion accuracy requires using the LK-G5000 laser sensor to measure the guideway’s straightness. The result verified the machine tool’s design index, with the Z- and Y-axes’ straightness being better than 2.42

μ

m

/ 800

mm and 2.32

μ

m

/ 200

mm, respectively. Ultimately, the device’s machining accuracy was confirmed. Experiments with flying-cut machining on a 190 × 140 mm ceramic-copper substrate yielded a roughness of Sa9.058 nm. According to the experimental results, the developed machine tool can fulfil the design specifications. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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22 pages, 7385 KiB

Open AccessArticle

Predicting the Dynamic Parameters for Milling Thin-Walled Blades with a Neural Network

by Yu Li, Feng Ding, Dazhen Wang, Weijun Tian and Jinhua Zhou

J. Manuf. Mater. Process. 2024, 8(2), 43; https://doi.org/10.3390/jmmp8020043 - 21 Feb 2024

Cited by 1 | Viewed by 2058

Abstract

Accurately predicting the time-varying dynamic parameters of a workpiece during the milling of thin-walled parts is the foundation of adaptively selecting chatter-free machining parameters. Hence, a method for accurately and quickly predicting the time-varying dynamic parameters for milling thin-walled parts is proposed, which [...] Read more.

Accurately predicting the time-varying dynamic parameters of a workpiece during the milling of thin-walled parts is the foundation of adaptively selecting chatter-free machining parameters. Hence, a method for accurately and quickly predicting the time-varying dynamic parameters for milling thin-walled parts is proposed, which is based on the shell FEM and a three-layer neural network. The time-dependent dynamics of the workpiece can be calculated using the FEM by obtaining the geometrical parameters of the arc-faced junctions within the discrete cells of the initial and machined workpiece. It is unnecessary to re-divide the mesh cells of the thin-walled parts at each cutting position, which enhances the computational efficiency of the workpiece dynamics. Meanwhile, in comparison with the three-dimensional cube elements, the shell elements can reduce the number of degrees of freedom of the FEM model by 74%, which leads to the computation of the characteristic equation that is about nine times faster. The results of the modal test show that the maximum error of the shell FEM in predicting the natural frequency of the workpiece is about 4%. Furthermore, a three-layer neural network is constructed, and the results of the shell FEM are used as samples to train the model. The neural network model has a maximum prediction error of 0.409% when benchmarked against the results of the FEM. Furthermore, the three-layer neural network effectively enhances computational efficiency while guaranteeing accuracy. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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14 pages, 6772 KiB

Open AccessArticle

Compensation Method for Correcting the Topography Convolution of the 3D AFM Profile Image of a Diffraction Grating

by Kai Zhang, Yang Bai and Zhimin Zhang

Machines 2024, 12(2), 126; https://doi.org/10.3390/machines12020126 - 10 Feb 2024

Cited by 3 | Viewed by 2198

Abstract

Any 3D AFM image is a convolution of the geometry of the AFM tip and the profile of the scanned sample, especially when the dimensions of the scanned sample are comparable to those of the AFM tip shape. The precise profile of the [...] Read more.

Any 3D AFM image is a convolution of the geometry of the AFM tip and the profile of the scanned sample, especially when the dimensions of the scanned sample are comparable to those of the AFM tip shape. The precise profile of the scanned sample can be extracted from the 3D AFM image if the geometry of the AFM tip is known. Therefore, in order to separate the geometry of the AFM probe tip from the 3D AFM image of a diffraction grating with a rectangular profile and to correct for the topographic convolutions induced by the AFM probe tip, a method is used to quantitatively evaluate the geometry of the AFM probe tip, including the tip radius and the included angle. A model for reconstructing the measured AFM image is proposed to correct topography convolutions caused by the AFM tip shape when scanning a diffraction grating with rectangular profiles. A series of experiments were performed to verify the effectiveness of the proposed AFM tip geometry evaluation method, and comparison experiments were conducted to demonstrate the feasibility and reliability of the proposed reconstruction model. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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16 pages, 6225 KiB

Open AccessArticle

Effect of Duty Cycle on Cutting Force for Ultrasonic Vibration-Assisted Milling Carbon Fiber-Reinforced Polymer Laminates

by Yukun Zhang, Junxue Ren and Jinhua Zhou

Materials 2023, 16(23), 7457; https://doi.org/10.3390/ma16237457 - 30 Nov 2023

Cited by 1 | Viewed by 1257

Abstract

Cutting force is an important factor that affects the surface quality of machining carbon fiber-reinforced polymer (CFRP). High cutting force can lead to surface damage such as the burrs and the delamination in the machining process of CFRP. Ultrasonic vibration-assisted machining (UVAM) can [...] Read more.

Cutting force is an important factor that affects the surface quality of machining carbon fiber-reinforced polymer (CFRP). High cutting force can lead to surface damage such as the burrs and the delamination in the machining process of CFRP. Ultrasonic vibration-assisted machining (UVAM) can reduce the cutting force in the machining process. This work is focused on the relationship between the duty cycle and the cutting force in UVAM of CFRP. Based on the kinematics of UVAM, the movement of the cutting tool edge and the tool–workpiece separation in UVAM were analyzed, and a calculation formula for the duty cycle was obtained. The milling experiment of CFRP was conducted to compare the cutting force between UVAM and conventional machining (CM), and the relationship between the reduction in the cutting force in UVAM and the duty cycle was determined. The experimental results showed that when the duty cycle was 0.2916, the cutting force of UVAM was reduced by 7.4% to 27% compared with that of CM. When the duty cycle was 1, the cutting force of UVAM was reduced by −4.5% to 7.5% compared with that of CM. Therefore, the effect of reducing the cutting force of UVAM can be enhanced by adjusting the process parameters to reduce the duty cycle of UVAM, and a lower cutting force can be obtained. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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17 pages, 8699 KiB

Open AccessArticle

Analysis, Modeling and Experimental Study of the Normal Contact Stiffness of Rough Surfaces in Grinding

by Yuzhu Bai, Xiaohong Jia, Fei Guo and Shuangfu Suo

Lubricants 2023, 11(12), 508; https://doi.org/10.3390/lubricants11120508 - 30 Nov 2023

Viewed by 2241

Abstract

Grinding is the most important method in machining, which belongs to the category of precision machining processes. Many mechanical bonding surfaces are grinding surfaces. Therefore, the contact mechanism of grinding a joint surface is of great significance for predicting the loading process and [...] Read more.

Grinding is the most important method in machining, which belongs to the category of precision machining processes. Many mechanical bonding surfaces are grinding surfaces. Therefore, the contact mechanism of grinding a joint surface is of great significance for predicting the loading process and dynamic characteristics of precision mechanical products. In this paper, based on the collected grinding surface roughness data, the profile parameters and topography characteristics of the asperity were analyzed, the rough surface data were fitted, the asperity profile was reconstructed, and the parabola y = nx² + mx + l of the cylindrical asperity model was established. After analyzing the rough surface data of the grinding process, the asperity distribution height was fitted with a Gaussian distribution function, which proved that asperity follows the Gaussian distribution law. The validity of this model was confirmed by the non-dimensional processing of the assumed model and the fitting of six plasticity indices. When the pressure is the same, the normal stiffness increases with the decrease in the roughness value of the joint surface. The experimental stiffness values are basically consistent with the fitting stiffness values of the newly established model, which verifies the reliability and effectiveness of the new model established for the grinding surface. In this paper, a new model for grinding joint surface is established, and an experimental platform is set up to verify the validity of the model. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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15 pages, 5592 KiB

Open AccessArticle

Innovative Post-Processing for Complex Geometries and Inner Parts of 3D-Printed AlSi10Mg Devices

by Martí Calvet, Anna Domènech, Sergi Vilaró, Toni Meseguer and Lorenzo Bautista

Materials 2023, 16(21), 7040; https://doi.org/10.3390/ma16217040 - 4 Nov 2023

Viewed by 2017

Abstract

A new technology consisting of new and sustainable chemical polishing treatment for aluminum components with complex shapes, such as heat exchangers, manifolds, busbars, aerospace devices, etc., manufactured by Additive Manufacturing (AM) technologies is described in this paper. This technology will contribute to the [...] Read more.

A new technology consisting of new and sustainable chemical polishing treatment for aluminum components with complex shapes, such as heat exchangers, manifolds, busbars, aerospace devices, etc., manufactured by Additive Manufacturing (AM) technologies is described in this paper. This technology will contribute to the development of a more efficient manufacturing process driven by AM, reinforcing the main idea of AM, which is based on reducing the amount of material and achieving cost savings through smart and improved designs. The present study shows a significant reduction in the surface roughness of consolidated AlSi10Mg metal parts manufactured by the SLM technique after carrying out the new chemical polishing post-process investigated in this work. Roughness values have been measured by mechanical and optical profilometry. The results obtained demonstrate the effectiveness of the chemical polishing, decreasing the roughness by up to 40%, being a reproducible and repeatable post-process. The presence of smut as solid residues on such types of chemical treatments has been also analyzed with XRF and ICP-MS techniques. The results obtained show that Si and Mg precipitates are removed from the metal surface at the last step of the investigated post-process. The percentages of the elements decrease from 25.0% to 8.09% Si and from 0.86% to 0.42% Mg, achieving the alloy smut-free composition on the metal surface. Tensile strength measurements have shown that the post-process described not only maintains the mechanical properties of the bulk material but, in comparison with non-post-processed parts, a slight improvement is observed with respect to the initial values, Young modulus (61.1 GPa to final 62.2 GPa), yield strength (from 236.8 to 246.7 MPa), and tensile strength (from 371.9 to 382.5 MPa) is observed, suggesting that the post-process has positive impact on the printed metal part. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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19 pages, 5991 KiB

Open AccessArticle

Wire Electrical Discharge Machining of AISI304 and AISI316 Alloys: A Comparative Assessment of Machining Responses, Empirical Modeling and Multi-Objective Optimization

by Mona A. Aboueleaz, Noha Naeim, Islam H. Abdelgaliel, Mohamed F. Aly and Ahmed Elkaseer

J. Manuf. Mater. Process. 2023, 7(6), 194; https://doi.org/10.3390/jmmp7060194 - 3 Nov 2023

Cited by 5 | Viewed by 2381

Abstract

This research investigates the multi-response of both material removal rate (MRR) and surface roughness (Ra) for the wire electrical discharge machining (WEDM) of two stainless steel alloys: AISI 304 and AISI 316. Experimental results are utilized to compare the machining responses obtained for [...] Read more.

This research investigates the multi-response of both material removal rate (MRR) and surface roughness (Ra) for the wire electrical discharge machining (WEDM) of two stainless steel alloys: AISI 304 and AISI 316. Experimental results are utilized to compare the machining responses obtained for AISI 316 with those obtained for AISI 304, as previously reported in the literature. The experimental work is conducted through a full factorial experimental design of five running parameters with different levels: applied voltage, transverse feed, pulse-on/pulse-off times and current intensity. The machined workpieces are analyzed using an image processing technique in order to evaluate the size of cut slots to allow the calculation of the MRR. Followed by the characterization of the surface roughness along the side walls of the slots. Different mathematical regression techniques were developed to represent the multi-response of both materials using the MATLAB regression toolbox. It was found that WEDM process parameters have a fuzzy influence on the responses of both material models. This allowed for multi-objective optimization of the regression models using four different techniques: multi-objective genetic algorithm (MOGA), multi-objective pareto search algorithm (MOPSA), weighted value grey wolf optimizer (WVGWO) and osprey optimization algorithm (OOA). The optimization results reveal that the optimal WEDM parameters of each response are inconsistent to the others. Hence, the optimal results are considered a compromise between the best results of different responses. Noteworthily, the multi-objective pareto search algorithm outperformed the other candidates. Eventually, the optimal results of both materials share the high voltage, high transverse feed rate and low pulse-off time parameters; however, AISI 304 requires low pulse-on time and current intensity levels while AISI 316 optimal results entail higher pulse-on time and current levels. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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14 pages, 11189 KiB

Open AccessArticle

Evolution of CrC_x Ceramic Induced by Laser Direct Energy Deposition Multilayered Gradient Ni204-dr60 Coating

by Yu Zhao, Ruobing Wang, Jian Zhang, Muhammad Imran Farid, Wenzheng Wu and Tianbiao Yu

Materials 2023, 16(21), 6865; https://doi.org/10.3390/ma16216865 - 26 Oct 2023

Viewed by 1379

Abstract

The manufacturing process for many large components of machines leads to a difference in their properties and performances based on changes in location. Functionally graded materials can meet these requirements and address the issue of generation and expansion of interface cracks. Ni204–dr60 gradient [...] Read more.

The manufacturing process for many large components of machines leads to a difference in their properties and performances based on changes in location. Functionally graded materials can meet these requirements and address the issue of generation and expansion of interface cracks. Ni204–dr60 gradient coatings were successfully fabricated using laser direct energy deposition (LDED). Microstructure mechanism evolution and microhardness of the gradient coating were comprehensively investigated. The change in the precipitated phase at the grain boundary and the intergranular zones resulted in a change in microstructural characteristics and also affected the microhardness distribution. The reinforced phase of the Ni204 → dr60 gradient zone from Ni204 to dr60 gradually precipitated and was rich in Mo and Nb phase, lath-shaped CrC_x phase, network-shaped CrC_x phase, block shape (Ni, Si) (C, B) phase, block CrC_x phase, and block Cr (B, C) phase. The gradient coating thus acts as a potential candidate to effectively solve the problem of crack generation at the interface of dr60 and the substrate. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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15 pages, 5189 KiB

Open AccessArticle

Biological Performance of Duplex PEO + CNT/PCL Coating on AZ31B Mg Alloy for Orthopedic and Dental Applications

by Morteza Daavari, Masoud Atapour, Marta Mohedano, Endzhe Matykina, Raul Arrabal and Dobrila Nesic

J. Funct. Biomater. 2023, 14(9), 475; https://doi.org/10.3390/jfb14090475 - 16 Sep 2023

Cited by 1 | Viewed by 2334

Abstract

To regulate the degradation rate and improve the surface biocompatibility of the AZ31B magnesium alloy, three different coating systems were produced via plasma electrolytic oxidation (PEO): simple PEO, PEO incorporating multi-walled carbon nanotubes (PEO + CNT), and a duplex coating that included a [...] Read more.

To regulate the degradation rate and improve the surface biocompatibility of the AZ31B magnesium alloy, three different coating systems were produced via plasma electrolytic oxidation (PEO): simple PEO, PEO incorporating multi-walled carbon nanotubes (PEO + CNT), and a duplex coating that included a polycaprolactone top layer (PEO + CNT/PCL). Surfaces were characterized by chemical content, roughness, topography, and wettability. Biological properties analysis included cell metabolism and adhesion. PEO ± CNT resulted in an augmented surface roughness compared with the base material (BM), while PCL deposition produced the smoothest surface. All surfaces had a contact angle below 90°. The exposure of gFib-TERT and bmMSC to culture media collected after 3 or 24 h did not affect their metabolism. A decrease in metabolic activity of 9% and 14% for bmMSC and of 14% and 29% for gFib-TERT was observed after 3 and 7 days, respectively. All cells died after 7 days of exposure to BM and after 15 days of exposure to coated surfaces. Saos-2 and gFib-TERT adhered poorly to BM, in contrast to bmMSC. All cells on PEO anchored into the pores with filopodia, exhibited tiny adhesion protrusions on PEO + CNT, and presented a web-like spreading with lamellipodia on PEO + CNT/PCL. The smooth and homogenous surface of the duplex PEO + CNT/PCL coating decreased magnesium corrosion and led to better biological functionality. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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18 pages, 11701 KiB

Open AccessArticle

Dynamic Analysis of the Thermo-Deformation Treatment Process of Flat Surfaces of Machine Parts

by Volodymyr Gurey, Pavlo Maruschak, Ihor Hurey, Volodymyr Dzyura, Tetyana Hurey and Weronika Wojtowicz

J. Manuf. Mater. Process. 2023, 7(3), 101; https://doi.org/10.3390/jmmp7030101 - 20 May 2023

Cited by 4 | Viewed by 1822

Abstract

Thermo-deformation treatment refers to methods of strengthening during which strengthened layers with a nanocrystalline structure are formed in the surface layers by modifying the metal surface layer, which changes its phase and structural and chemical compositions, reduces grain size, and improves performance. Grinding [...] Read more.

Thermo-deformation treatment refers to methods of strengthening during which strengthened layers with a nanocrystalline structure are formed in the surface layers by modifying the metal surface layer, which changes its phase and structural and chemical compositions, reduces grain size, and improves performance. Grinding of the metal structure was achieved by combining two methods simultaneously during this treatment: the action of a highly concentrated energy source on the surface layer and intense plastic deformation. The source of highly concentrated energy was generated in the contact zone of the tool-disc, which rotates at high speed during friction on the treated surface. Intense deformation was achieved due to the grooves on the tool’s working surface. Dynamic analysis of the thermo-deformation treatment process of flat surfaces of machine parts and a calculation scheme of the surface grinder machine’s elastic system, which is the three-mass model, were developed. When the groove width increased from 4 mm to 8 mm, the force amplitude in the contact zone increased from 10 N to 75 N. Accordingly, the thickness of the nanocrystalline layer increased from 190–220 μm to 250–260 μm, and its hardness increased from 9.3 GPa to 11.1 GPa. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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15 pages, 3142 KiB

Open AccessEditor’s ChoiceArticle

Determination of the Cutting-Edge Microgeometry Based on Process Forces during Peripheral Milling of Ti-6Al-4V Using Machine Learning

by Matthias Wimmer, Roman Hartl and Michael F. Zaeh

J. Manuf. Mater. Process. 2023, 7(3), 100; https://doi.org/10.3390/jmmp7030100 - 19 May 2023

Cited by 5 | Viewed by 2571

Abstract

The residual stress state of the machined sub-surface influences the service quality indicators of a component, such as fatigue life, tribological properties, and distortion. During machining, the radius of the cutting edge changes due to tool wear. The cutting-edge rounding significantly affects the [...] Read more.

The residual stress state of the machined sub-surface influences the service quality indicators of a component, such as fatigue life, tribological properties, and distortion. During machining, the radius of the cutting edge changes due to tool wear. The cutting-edge rounding significantly affects the residual stress state in the part and the occurring process forces. This paper presents a tool wear prediction model based on in-process measured cutting forces. The effects of the cutting-edge geometry on the force behavior and the machining-induced residual stresses were examined experimentally. The resulting database was used to realize a Machine Learning algorithm to calculate the hidden value of tool wear. The predictions were validated by milling experiments using rounded cutting edges for different process parameters. The microgeometry of the cutting edge could be determined with a Root Mean Square Error of 8.94 μm. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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17 pages, 4498 KiB

Open AccessArticle

Engineered Cross-Linked Silane with Urea Polymer Thin Durable Coatings onto Polymeric Films for Controlled Antiviral Release of Activated Chlorine and Essential Oils

by Elisheva Sasson, Omer Agazani, Eyal Malka, Meital Reches and Shlomo Margel

J. Funct. Biomater. 2023, 14(5), 270; https://doi.org/10.3390/jfb14050270 - 12 May 2023

Cited by 3 | Viewed by 2251

Abstract

In March 2020, the World Health Organization announced a pandemic attributed to SARS-CoV-2, a novel beta-coronavirus, which spread widely from China. As a result, the need for antiviral surfaces has increased significantly. Here, the preparation and characterization of new antiviral coatings on polycarbonate [...] Read more.

In March 2020, the World Health Organization announced a pandemic attributed to SARS-CoV-2, a novel beta-coronavirus, which spread widely from China. As a result, the need for antiviral surfaces has increased significantly. Here, the preparation and characterization of new antiviral coatings on polycarbonate (PC) for controlled release of activated chlorine (Cl⁺) and thymol separately and combined are described. Thin coatings were prepared by polymerization of 1-[3-(trimethoxysilyl)propyl] urea (TMSPU) in ethanol/water basic solution by modified Stöber polymerization, followed by spreading the formed dispersion onto surface-oxidized PC film using a Mayer rod with appropriate thickness. Activated Cl-releasing coating was prepared by chlorination of the PC/SiO₂-urea film with NaOCl through the urea amide groups to form a Cl-amine derivatized coating. Thymol releasing coating was prepared by linking thymol to TMSPU or its polymer via hydrogen bonds between thymol hydroxyl and urea amide groups. The activity towards T4 bacteriophage and canine coronavirus (CCV) was measured. PC/SiO₂-urea-thymol enhanced bacteriophage persistence, while PC/SiO₂-urea-Cl reduced its amount by 84%. Temperature-dependent release is presented. Surprisingly, the combination of thymol and chlorine had an improved antiviral activity, reducing the amount of both viruses by four orders of magnitude, indicating synergistic activity. For CCV, coating with only thymol was inactive, while SiO₂-urea-Cl reduced it below a detectable level. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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11 pages, 5175 KiB

Open AccessArticle

Effect of CH₄ Flow Rate on the Tribological Behaviors of TiCN Films against Si₃N₄ Ceramic and Steel Ball

by Yanhong Lyu, Jianyun Zheng, Huilian Sun, Xinrong Deng, Yang Liu and Qiaoyu Zhang

Lubricants 2023, 11(5), 209; https://doi.org/10.3390/lubricants11050209 - 8 May 2023

Cited by 1 | Viewed by 2032

Abstract

Control of the structural, mechanical and tribological properties of TiCN films play an important role in its numerous applications, including the cutting tools, mechanical components, aeronautical and biomedical engineering industries. Direct-current magnetron sputtering (DCMS) system was applied to deposit TiCN films onto n-type [...] Read more.

Control of the structural, mechanical and tribological properties of TiCN films play an important role in its numerous applications, including the cutting tools, mechanical components, aeronautical and biomedical engineering industries. Direct-current magnetron sputtering (DCMS) system was applied to deposit TiCN films onto n-type silicon (100) at room temperature. The Ti-TiN interlayer was used to enhance the adhesive strength between the coating and the substrate. The composition and microstructure of the TiCN films were studied using X-ray photoelectron spectroscopy (XPS) and field-emitted scanning electron microscopy (FESEM). The mechanical properties of the films as a function of methane (CH₄) flow ratio were then characterized using nano-indentation measurements. The tribological behavior of TiCN films was investigated by UMT-2MT tribometer against a Si₃N₄ ceramic and AISI52100 steel ball. After the tribological tests, the wear rate of the films was obtained by the 3D surface profiler and the component content of wear debris was evaluated by energy dispersive X-ray spectroscopy (EDS). The results show that the tribological properties of TiCN films are a function of CH₄ flow rates. The film obtained at a 10 sccm CH₄ flow rate possesses a minimum average COF value of 0.1964 and reaches 72,000 cycles against a Si₃N₄ ball over the test duration. Furthermore, the wear rate was only 2.076 × 10⁻⁶ mm³/N·m. Furthermore, the TiCN films exhibited longer lifespan against the Si₃N₄ ball than against the steel ball under the normal load of 1 N, indicating that the TiCN films present better lubricative properties when against low-hardness counterparts than high-hardness counterparts. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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13 pages, 3734 KiB

Open AccessEditor’s ChoiceArticle

Process Map Definition for Laser Metal Deposition of VDM Alloy 780 on the 316L Substrate

by Pascal Paulus, Yannick Ruppert, Michael Vielhaber and Juergen Griebsch

J. Manuf. Mater. Process. 2023, 7(3), 86; https://doi.org/10.3390/jmmp7030086 - 26 Apr 2023

Cited by 3 | Viewed by 2357

Abstract

VDM Alloy 780 is a novel Ni-based superalloy that allows for approximately 50 °C higher operating temperatures, compared to Inconel 718, without a significant decrease in mechanical properties. The age hardenable NiCoCr Alloy combines increased temperature strength with oxidation resistance, as well as [...] Read more.

VDM Alloy 780 is a novel Ni-based superalloy that allows for approximately 50 °C higher operating temperatures, compared to Inconel 718, without a significant decrease in mechanical properties. The age hardenable NiCoCr Alloy combines increased temperature strength with oxidation resistance, as well as improved microstructural stability due to γ′-precipitation. These advantages make it suitable for wear- and corrosion-resistant coatings that can be used in high temperature applications. However, VDM Alloy 780 has not yet been sufficiently investigated for laser metal deposition applications. A design of experiments with single tracks on 316L specimens was carried out to evaluate the influence of the process parameters on clad quality. Subsequently, the quality of the clads was evaluated by means of destructive and non-destructive testing methods, in order to verify the suitability of VDM Alloy 780 for laser metal deposition applications. The single-track experiments provide a basis for coating or additive manufacturing applications. For conveying the results, scatter plots with regression lines are presented, which illustrate the influence of specific energy density on the resulting porosity, dilution, powder efficiency, aspect ratio, width and height. Finally, the clad quality, in terms of porosity, is visualized by two process maps with different mass per unit lengths. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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16 pages, 6858 KiB

Open AccessArticle

Influence of Laser Surface Texture on the Anti-Friction Properties of 304 Stainless Steel

by Xiashuang Li, Guifeng Li, Yuesui Lei, Lei Gao, Lin Zhang and Kangkang Yang

Machines 2023, 11(4), 473; https://doi.org/10.3390/machines11040473 - 12 Apr 2023

Cited by 8 | Viewed by 2641

Abstract

To enhance the anti-friction properties of 304 stainless steel, friction experiments were conducted on it after laser surface texturing. The influences of laser scanning speed, repetition frequency, processing times, laser beam line spacing, and lattice spacing on the friction properties of 304 stainless [...] Read more.

To enhance the anti-friction properties of 304 stainless steel, friction experiments were conducted on it after laser surface texturing. The influences of laser scanning speed, repetition frequency, processing times, laser beam line spacing, and lattice spacing on the friction properties of 304 stainless steel were investigated by contrast tests under annular filling mode. The results revealed that laser texturing improved the anti-friction properties of 304 stainless steel. The friction coefficient of the sample surface decreased first and then increased with the increase in scanning speed, repetition frequency, processing times, laser beam line spacing, and lattice spacing. Based on this, process optimization found that a stainless steel surface with good anti-friction properties could be obtained when the laser power was 0.3 W, the repetition frequency was 50 kHz, the scanning speed was 80 mm/s, the laser beam line spacing was 1 μm, the lattice spacing was 200 μm, and the number of processing times was two. Finally, scanning electron microscope (SEM) characterization of wear morphology on the sample surface showed that the laser textured surface could collect debris during effective friction, which reduced the occurrence of abrasive and adhesive wear. Meanwhile, the actual contact area of the friction pair was effectively reduced, thereby reducing friction force and wear. This study provided experimental data and a theoretical basis for improving the friction properties of the 304 stainless steel surface and laid the foundation for its reliable use under friction and wear conditions. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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12 pages, 5744 KiB

Open AccessArticle

Effect of Coated Composite Micro–Texture Tool on Cutting Shape and Cutting Force during Aluminum Alloy Cutting

by Qinghua Li, Chunlu Ma, Lintao Xie, Baizhong Wang and Shihong Zhang

Machines 2023, 11(4), 439; https://doi.org/10.3390/machines11040439 - 29 Mar 2023

Cited by 2 | Viewed by 1890

Abstract

Aluminum alloy materials are very difficult to break in the processing process; chip accumulation leads to poor processing stability. In this paper, a coated composite micro–textured tool is presented. The influence of coated composite micro–textured tool on chip shape and cutting force under [...] Read more.

Aluminum alloy materials are very difficult to break in the processing process; chip accumulation leads to poor processing stability. In this paper, a coated composite micro–textured tool is presented. The influence of coated composite micro–textured tool on chip shape and cutting force under the same cutting parameters is studied. Firstly, the combination of cutting force and cutting temperature is optimized based on cutting test. Secondly, combined with the finite element simulation technology, three kinds of composite micro–texture tools are tested to determine the same cutting parameters, tools and workpiece materials, and optimize the composite micro–texture combination from the angle of chip shape, cutting temperature and cutting force. Finally, on the basis of optimizing the microstructure combination, the optimization of the cutting performance of aluminum alloy by coating material is studied. It was found that the chip was more easily broken in the composite microstructure when two tools were used. The cutting force decreased by 25% and the cutting temperature decreased by 9.09% compared with the non–micro–texture tools. The cutting temperature and cutting force decreased by 3% and 4.99% compared with those of uncoated composite microstructure. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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16 pages, 9742 KiB

Open AccessArticle

Conical Grinding Wheel Ultrasonic-Assisted Grinding Micro-Texture Surface Formation Mechanism

by Jiaying Han, Yiqi Jiang, Xinrui Li and Qing Li

Machines 2023, 11(4), 428; https://doi.org/10.3390/machines11040428 - 27 Mar 2023

Cited by 2 | Viewed by 3448

Abstract

The rotating ultrasonic-assisted grinding (RUAG) experiment of the conical grinding wheel generated the intermittent pit-shaped micro-texture on the surface of the workpiece, reducing thermal damage and improving the lubrication characteristics compared with conventional grinding (CG). To further optimize the surface properties, this paper [...] Read more.

The rotating ultrasonic-assisted grinding (RUAG) experiment of the conical grinding wheel generated the intermittent pit-shaped micro-texture on the surface of the workpiece, reducing thermal damage and improving the lubrication characteristics compared with conventional grinding (CG). To further optimize the surface properties, this paper studied the formation mechanism of micro-texture. This study used as basis the theory that micro-debris volume equals the macroscopic material removal one to establish the mathematical equation of grinding depth. Thereafter, formulas of micro-texture feature parameters, including pit length, pit depth, and texture spacing were deduced. The solved microscopic grinding depth was alternatingly positive and negative, indicating that the alternating separation between the grinding grain and workpiece caused intermittent pits in the grinding. Through response surface analysis (RSA), this paper analyzed the relationships among macroscopic grinding depth, micro-texture feature parameters, and machining parameters (i.e., amplitude, feed rate, and rotational speed). Single-factor experiments of machining parameters, with finite element simulation and experiment methods, were performed to verify the theoretical micro-texture features. The simulated program formed three-dimensional surfaces with micro-textures. Their measurement results were consistent with the theoretical ones. Experimental results proved that the range of pit length covers the theoretical ones, further verifying the accuracy of the grinding depth model. For this grinding wheel, the 8–10 μm amplitude was optimal for better roughness, lubrication, and thermal damage. Roughness was improved when increasing the rotational speed or reducing the feed rate based on the experiment. If the rotational speed and feed rate exceed the limiting values, then continuous grinding will break down the abrasive grains and even damage the cubic boron nitride (CBN) coating. Experimental results likewise showed that the pit shape was closely related to the surface properties, which deserves further investigation. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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14 pages, 9003 KiB

Open AccessArticle

Investigation on White Layer Formation in Dry High-Speed Milling of Nickel-Based Superalloy GH4169

by Jiamao Zhang, Jin Du, Binxun Li and Guosheng Su

Machines 2023, 11(3), 406; https://doi.org/10.3390/machines11030406 - 21 Mar 2023

Cited by 9 | Viewed by 2568

Abstract

To investigate the formation mechanism of the white layer on the machined surface during high-speed milling of nickel-based superalloy GH4169, several cutting parameters were selected for milling experiments. Energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and electron backscattered diffraction (EBSD) were employed to [...] Read more.

To investigate the formation mechanism of the white layer on the machined surface during high-speed milling of nickel-based superalloy GH4169, several cutting parameters were selected for milling experiments. Energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and electron backscattered diffraction (EBSD) were employed to characterize element distribution, phase transformation, and microstructure changes in the machined surface of the superalloy and then reveal the formation mechanism of the white layer on the machined surface. The results show that the white layer appears on the machined surface of GH4169, which is dense and has no obvious structural features. The total amount of elements in the white layer remains unchanged, but the distribution of elements such as C, N, O, Fe, and Ni changes due to phase change. The formation mechanism of the white layer is due to the dynamic recovery and dynamic recrystallization caused by the heat–force coupling effect, which leads to the grain refinement of the material and thus forms the white layer. This investigation can provide theoretical support to improve the service life of the parts in actual machining. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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12 pages, 3766 KiB

Open AccessArticle

Effect of Interbody Implants on the Biomechanical Behavior of Lateral Lumbar Interbody Fusion: A Finite Element Study

by Hangkai Shen, Jia Zhu, Chenhui Huang, Dingding Xiang and Weiqiang Liu

J. Funct. Biomater. 2023, 14(2), 113; https://doi.org/10.3390/jfb14020113 - 17 Feb 2023

Cited by 5 | Viewed by 2500

Abstract

Porous titanium interbody scaffolds are growing in popularity due to their appealing advantages for bone ingrowth. This study aimed to investigate the biomechanical effects of scaffold materials in both normal and osteoporotic lumbar spines using a finite element (FE) model. Four scaffold materials [...] Read more.

Porous titanium interbody scaffolds are growing in popularity due to their appealing advantages for bone ingrowth. This study aimed to investigate the biomechanical effects of scaffold materials in both normal and osteoporotic lumbar spines using a finite element (FE) model. Four scaffold materials were compared: Ti6Al4V (Ti), PEEK, porous titanium of 65% porosity (P65), and porous titanium of 80% porosity (P80). In addition, the range of motion (ROM), endplate stress, scaffold stress, and pedicle screw stress were calculated and compared. The results showed that the ROM decreased by more than 96% after surgery, and the solid Ti scaffold provided the lowest ROM (1.2–3.4% of the intact case) at the surgical segment among all models. Compared to solid Ti, PEEK decreased the scaffold stress by 53–66 and the endplate stress by 0–33%, while porous Ti decreased the scaffold stress by 20–32% and the endplate stress by 0–32%. Further, compared with P65, P80 slightly increased the ROM (<0.03°) and pedicle screw stress (<4%) and decreased the endplate stress by 0–13% and scaffold stress by approximately 18%. Moreover, the osteoporotic lumbar spine provided higher ROMs, endplate stresses, scaffold stresses, and pedicle screw stresses in all motion modes. The porous Ti scaffolds may offer an alternative for lateral lumbar interbody fusion. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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17 pages, 16399 KiB

Open AccessArticle

Simulation Study on Bearing Lubrication Mechanism and Friction Characteristics of the Biomimetic Non-Smooth Surface of a Cross-Scale, Second-Order Compound Microstructure

by Yingna Liang, Cunyuan Wang, Zongyi Zhang, Zhepeng Zhang, Wei Wang, Hao Xing, Tianyuan Guan and Dianrong Gao

Lubricants 2023, 11(2), 77; https://doi.org/10.3390/lubricants11020077 - 11 Feb 2023

Cited by 8 | Viewed by 2074

Abstract

The reasonable design of biomimetic non-smooth surfaces is a novel and effective way to solve problems such as the poor lubricity and serious friction and wear of friction pairs of seawater axial piston pumps. Inspired by cross-scale, second-order compound microstructures on the surfaces [...] Read more.

The reasonable design of biomimetic non-smooth surfaces is a novel and effective way to solve problems such as the poor lubricity and serious friction and wear of friction pairs of seawater axial piston pumps. Inspired by cross-scale, second-order compound microstructures on the surfaces of some living organisms, a hydrodynamic lubrication model of a slipper pair with a surface featuring spherical pits containing spherical convex hulls was built. This study analyzed the bearing lubrication mechanism and friction characteristics of cross-scale, second-order compound microstructure from the microflow perspective via the CFD method and optimized the working and geometric parameters using a hybrid orthogonal test scheme. The study’s results show that the cross-scale, second-order compound microstructure can produce a superimposed hydrodynamic pressure effect to improve the bearing capacity of the lubrication film of a slipper pair, reducing the friction coefficient. The orders of factors (the working parameter and geometric parameters) under multiple indices (the total pressure-bearing capacity and the friction coefficient) were found. The optimal combination is a spherical pit with a first order diameter of 0.7 mm, a first order depth-to-diameter ratio of 0.1, an area rate of 20%, an arrangement angle of α/3 and a spherical convex hull with a second order diameter of 0.13 mm, and a second order depth-to-diameter ratio of 0.3. Compared to a smooth surface and a first-order, non-smooth microstructure, the cross-scale, second-order compound microstructure has an 11.0% and 8.9% higher total pressure-bearing capacity, respectively, and the friction coefficient decreased by 9.5% and 5.4%, respectively. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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16 pages, 9716 KiB

Open AccessArticle

Novel Tool Path Generation Method for Pocket Machining Using Sound Field Synthesis Theory

by Xuefeng Yang, Xulin Cai, Wenan Yang and Youpeng You

Machines 2023, 11(2), 131; https://doi.org/10.3390/machines11020131 - 18 Jan 2023

Cited by 1 | Viewed by 2537

Abstract

Contour parallel tool paths have been proved to be a preferred machining strategy for their advantage of less tool retractions and less sharp turns. The traditional geometrical algorithm-based tool path generation method often makes it hard to simply and simultaneously solve the problems [...] Read more.

Contour parallel tool paths have been proved to be a preferred machining strategy for their advantage of less tool retractions and less sharp turns. The traditional geometrical algorithm-based tool path generation method often makes it hard to simply and simultaneously solve the problems of self-intersection, no residual, and smoothness at the same time due to their contradictions. To address this issue, a contoured parallel tool path generation method for pocket machining is developed in this study. It is based on sound field synthesis theory inspired by the phenomenon of sound wave propagation. Firstly, the simplified medial axis (SMA) tree of the pocket is extracted and the propagation direction of each SMA segment is calculated on account of the geometric characteristics of the pocket boundary. Secondly, the final tool path is obtained through the synthesis of the sound field. Finally, the novel method is verified on five different pockets to generate a contoured parallel milling tool path. After machining these pockets and measuring the machining time, roughness, and cutting force, the experimental results demonstrate that the tool path obtained by the novel method has advantages in improving machining quality and efficiency. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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10 pages, 2108 KiB

Open AccessArticle

Effect of Microstructure of TiN /TiCN Layer on the Structural, Mechanical and Tribological Properties of the Ti/TiN/TiCN Films

by Yanhong Lyu, Qiaoyu Zhang, Yang Liu, Xinrong Deng, Huilian Sun and Min Mo

Lubricants 2023, 11(1), 21; https://doi.org/10.3390/lubricants11010021 - 5 Jan 2023

Cited by 3 | Viewed by 2381

Abstract

A direct current magnetron sputtering (DCMS) system at room temperature was applied to deposit the Ti/TiN/TiCN films. In order to research the effect of the microstructure of the TiN/TiCN layer on the Ti/TiN/TiCN films, the deposition time ratio of the TiN/TiCN layer ranged [...] Read more.

A direct current magnetron sputtering (DCMS) system at room temperature was applied to deposit the Ti/TiN/TiCN films. In order to research the effect of the microstructure of the TiN/TiCN layer on the Ti/TiN/TiCN films, the deposition time ratio of the TiN/TiCN layer ranged from 28.57 to 200%, and the whole deposition time of the films and the deposition time of Ti layer were constant. In this work, the relationship between structure and mechanical properties of films were investigated. The research results showed that the composition and structure of the films only slightly changed, while the crystalline orientation of the TiCN layer was of significant variation with the deposition time of the TiN layer. It is shown that the adhesion strength and internal stresses were 18.6 ± 1.5 N and 140 MPa when the deposition time ratio was 50%. By adjusting the deposition time ratio, the films displayed significant improvement in tribological behaviors. The coefficients of friction (COF) for the films deposited under deposition time ratio of 50% were about only 0.139 when the value of COF was stabilized. This work can provide a good wear-resisting film prepared approach at room temperature. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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9 pages, 5308 KiB

Open AccessArticle

Fretting Wear Characteristics of SLM-Formed 316L Stainless Steel in Seawater

by Mingji Huang, Ping Chen and Xiaoxi Qiao

Lubricants 2023, 11(1), 7; https://doi.org/10.3390/lubricants11010007 - 26 Dec 2022

Cited by 2 | Viewed by 2163

Abstract

The fretting wear characteristics of two different energy density 316L stainless steels formed by selective laser melting (SLM) under different friction conditions are studied. The image method was used to study the porosity of two samples with different energy densities (46.88 J/mm³ [...] Read more.

The fretting wear characteristics of two different energy density 316L stainless steels formed by selective laser melting (SLM) under different friction conditions are studied. The image method was used to study the porosity of two samples with different energy densities (46.88 J/mm³, 98.96 J/mm³) formed by SLM. The dynamic wear test, respectively, evaluates its wear morphology and wear depth under three conditions: dry friction, distilled water, and an 3.5% NaCl solution. The porosity of the samples with SLM forming an energy density of 46.88 J/

{mm}^{3}

and 98.96 J/

{mm}^{3}

are 7.66% and 1.00%, respectively. Under the three conditions, the friction coefficient and wear depth of the samples with high energy density are smaller than those of the samples with low energy density; the friction of the samples with two energy densities in aqueous solution is faster than dry friction in air and tends to be stable. The friction coefficient in 3.5% NaCl solution is the smallest; when the energy density is constant, the wear depth of the fretting wear is the largest under dry friction and the smallest in distilled water. Under dry-friction conditions, the wear mechanisms of fretting wear are mainly oxidative wear and adhesive wear. In the fretting wear in the distilled water and the 3.5% NaCl solution, both wear mechanisms are abrasive wear and fatigue wear. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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12 pages, 5585 KiB

Open AccessArticle

Effect of Process Parameters on Stress Field of Laser Additive Manufacturing

by Yulin Liu, Qi Li, Zhaohui Ren, Zeyu Jiang, Hengfa Luo and Xingwen Zhang

Machines 2022, 10(12), 1197; https://doi.org/10.3390/machines10121197 - 11 Dec 2022

Cited by 11 | Viewed by 2168

Abstract

In order to optimize the additive manufacturing process and find the process parameters affecting the mechanical properties of the parts, an additive manufacturing simulation model of Ti-6Al-4V titanium alloy was established, and the effects of ambient temperature, substrate thickness and wire temperature on [...] Read more.

In order to optimize the additive manufacturing process and find the process parameters affecting the mechanical properties of the parts, an additive manufacturing simulation model of Ti-6Al-4V titanium alloy was established, and the effects of ambient temperature, substrate thickness and wire temperature on the stress field and residual stress field were analyzed. The results show that the ambient temperature is inversely proportional to the residual stress of the cladding layer, while the substrate thickness and wire temperature are positively correlated to the residual stress of the cladding layer. When the ambient temperature increases from 0 °C to 600 °C, the maximum residual stress decreases by 36.0%, the maximum residual stress increases by 10.0% when the substrate thickness increases from 25 mm to 55 mm and the maximum residual stress increases by 7.48% when the temperature increases from 0 °C to 600 °C. The influence of the three parameters on the maximum residual stress is as follows: ambient temperature > substrate thickness > wire temperature. The research results can provide reference for stress control during actual manufacturing. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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