Materials

Research

Jump to: Review

14 pages, 9589 KiB

Open AccessArticle

Evolutions in Microstructure and Mechanical Properties of Ultra-Thin Oligocrystalline Invar Alloy Strip During Cold Rolling

by Jianguo Yang, Yajin Xia, Qingke Zhang, Genbao Chen, Cheng Xu, Zhenlun Song and Jiqiang Chen

Materials 2025, 18(9), 2026; https://doi.org/10.3390/ma18092026 - 29 Apr 2025

Viewed by 276

Abstract

The ultra-thin Invar alloy strips are widely used in the manufacture of the fine masks; cold rolling of such thin strips (<100 μm) poses significant difficulties, primarily due to the limited number of grains within the thickness range. Consequently, it is important to [...] Read more.

The ultra-thin Invar alloy strips are widely used in the manufacture of the fine masks; cold rolling of such thin strips (<100 μm) poses significant difficulties, primarily due to the limited number of grains within the thickness range. Consequently, it is important to understand the grain structure and property evolutions of the ultra-thin Invar alloy strips during cold rolling. In this study, an annealed Invar36 alloy strip, 100 µm thick, was cold rolled to different thicknesses, and the surface deformation morphologies, cross-sectional grain structure, intracrystalline microstructure and tensile properties of these thin strips were characterized and analyzed. The results show that plastic deformation of the initial annealed equiaxed grains is not uniform, depending on the grain orientation, resulting in different slip bands morphologies, unevenness and increase in roughness. Meanwhile, the grain rotation and rolling texture develop with increasing cold rolling reduction. The dislocation density in the 60% cold-rolled strip is about decuple that of the original annealed strip, and high-density tangled dislocations are formed, making the tensile strength increase from 430 MPa to 738 MPa. Grain refining and proper intermediate annealing are proposed to optimize the thickness uniformity, evenness and surface roughness. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

21 pages, 15963 KiB

Open AccessArticle

Analysis of the Wear of Forming Tools in the Process of Extruding Ceramic Bands Using Selected Research Methods for Evaluating Operational Durability

by Marek Hawryluk, Jan Marzec, Tadeusz Leśniewski, Justyna Krawczyk, Łukasz Madej and Konrad Perzyński

Materials 2025, 18(9), 1994; https://doi.org/10.3390/ma18091994 - 28 Apr 2025

Viewed by 312

Abstract

This article presents the results of research concerning a comprehensive analysis of the operation of tools used for forming ceramic roof tiles in the clay-based band extrusion process. The conducted studies demonstrated that key process parameters, such as extrusion pressure and the flow [...] Read more.

This article presents the results of research concerning a comprehensive analysis of the operation of tools used for forming ceramic roof tiles in the clay-based band extrusion process. The conducted studies demonstrated that key process parameters, such as extrusion pressure and the flow speed of the ceramic mass containing hard components, are crucial for the durability of the tools, significantly affecting their wear. The analysis of the formed mass revealed the presence of hard fractions, such as quartz, zircon, and garnet, which significantly contribute to tool abrasion. Among the tested hardening variants of NC11LV steel, the best results in terms of enhanced longevity were operational tools treated at 1020 °C and then tempered at 200 °C for two hours. These results were confirmed in both operational tests and the dry abrasion test, indicating high wear resistance. Additional hardening through nitriding further extended the tool’s lifespan. The greatest wear was observed in the tool made of Hardox 600 steel with an additional overlay weld, which was caused by improper welding techniques. Numerical modeling, particularly the mesh-free SPH approach, proved to be the most effective method for analyzing the ceramic mass extrusion process. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

21 pages, 3350 KiB

Open AccessArticle

Application of Machine Learning to the Prediction of Surface Roughness in the Milling Process on the Basis of Sensor Signals

by Katarzyna Antosz, Edward Kozłowski, Jarosław Sęp and Sławomir Prucnal

Materials 2025, 18(1), 148; https://doi.org/10.3390/ma18010148 - 2 Jan 2025

Cited by 1 | Viewed by 1107

Abstract

This article presents an investigation of the use of machine learning methodologies for the prediction of surface roughness in milling operations, using sensor data as the primary source of information. The sensors, which included current transformers, a microphone, and displacement sensors, captured comprehensive [...] Read more.

This article presents an investigation of the use of machine learning methodologies for the prediction of surface roughness in milling operations, using sensor data as the primary source of information. The sensors, which included current transformers, a microphone, and displacement sensors, captured comprehensive machining signals at a frequency of 10 kHz. The signals were subjected to preprocessing using the Savitzky–Golay filter, with the objective of isolating relevant moments of active material machining and reducing noise. Two machine learning models, namely Elastic Net and neural networks, were employed for the prediction purposes. The Elastic Net model demonstrated effective handling of multicollinearity and reduction in the data dimensionality, while the neural networks, utilizing the ReLU activation function, exhibited the capacity to capture complex, nonlinear patterns. The models were evaluated using the coefficient of determination (R²), which yielded values of 0.94 for Elastic Net and 0.95 for neural networks, indicating a high degree of predictive accuracy. These findings illustrate the potential of machine learning to optimize manufacturing processes by facilitating precise predictions of surface roughness. Elastic Net demonstrated its utility in reducing dimensionality and selecting features, while neural networks proved effective in modeling complex data. Consequently, these methods exemplify the efficacy of integrating data-driven approaches with robust predictive models to improve the quality and efficiency of surface. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

14 pages, 3670 KiB

Open AccessArticle

Mechanical Behavior of Oxide Dispersion Strengthened Steel Directly Consolidated by Rotary Swaging

by Radim Kocich, Lenka Kunčická, Petr Král and Karel Dvořák

Materials 2024, 17(19), 4831; https://doi.org/10.3390/ma17194831 - 30 Sep 2024

Cited by 1 | Viewed by 868

Abstract

Among the main benefits of powder-based materials is the possibility of combining different constituents to achieve enhanced properties of the fabricated bulk material. The presented study characterizes the micro- and sub-structures and related mechanical properties of ferritic steel strengthened with a fine dispersion [...] Read more.

Among the main benefits of powder-based materials is the possibility of combining different constituents to achieve enhanced properties of the fabricated bulk material. The presented study characterizes the micro- and sub-structures and related mechanical properties of ferritic steel strengthened with a fine dispersion of nano-sized Y₂O₃ oxide particles. Unlike the typical method of preparation via rolling, the material presented herein was fabricated by direct consolidation from a mixture of powders using the versatile method of hot rotary swaging. The mechanical properties were evaluated at room temperature and also at 1300 °C to document the suitability of the prepared steel for high-temperature applications. The results showed that the imposed shear strain, i.e., swaging ratio, is a crucial parameter influencing the microstructure and, thus, material behavior. The workpiece subjected to the swaging ratio of 1.4 already exhibited a sufficiently consolidated structure with ultra-fine grains and featured high room-temperature microhardness values (up to 690 HV0.5), as well as a relatively high maximum flow stress (~88 MPa) when deformed at the temperature of 1300 °C with the strain rate of 0.5 s⁻¹. However, the dispersion of oxides within this sample exhibited local inhomogeneities. Increasing the swaging ratio to 2.5 substantially contributed to the homogenization of the distribution of the Y₂O₃ oxide particles, which resulted in increased homogeneity of mechanical properties (lower deviations from the average values), but their lower absolute values due to the occurrence of nucleating nano-sized recrystallized grains. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

18 pages, 14089 KiB

Open AccessArticle

Change in Surface Roughness on the Inner and Outer Surfaces of the Microtube during Hollow Sinking

by Hayate Sakaguchi, Takuma Kishimoto, Saki Suematsu, Kenichi Tashima, Koichi Kano, Satoshi Kajino, Shiori Gondo and Shinsuke Suzuki

Materials 2024, 17(17), 4320; https://doi.org/10.3390/ma17174320 - 30 Aug 2024

Viewed by 1042

Abstract

Hollow sinking experiments and tensile tests were conducted to clarify the evolution of surface roughness during hollow sinking. Stainless steel tubes (outer diameter: 1.5 mm; wall thickness: 0.045 mm) featuring a single grain spanning the wall thickness achieved via annealing as the starting [...] Read more.

Hollow sinking experiments and tensile tests were conducted to clarify the evolution of surface roughness during hollow sinking. Stainless steel tubes (outer diameter: 1.5 mm; wall thickness: 0.045 mm) featuring a single grain spanning the wall thickness achieved via annealing as the starting material. The tube was drawn without an internal tool using a draw bench by controlling the tube drawing speed ratio of the die entrance and exit sides. The surface roughnesses of the inner and outer surfaces at the die entrance and exit sides of the drawn tube were compared with the surface roughnesses of the inner and outer surfaces under the uniaxial tensile deformation of the starting material. As a result, two major findings were revealed; the surface roughness formation behavior during the hollow sinking; the uniaxial tensile deformation exhibits a tube on both sides of the entrance and the exit of a die. Former uniaxial tensile deformation forms surface roughness of the tube at the die-entrance-side. However, hollow sinking reduces the roughness. The tube keeps its small roughness even though it is applied the later uniaxial tensile deformation behind the die exit. Furthermore, the conventional formula to predict the surface roughness of a metal sheet caused by the uniaxial tensile deformation can predict the surface roughness of a tube in the hollow sinking. At both die entrance and exit sides, the roughness of the inner surface was larger than that of the outer surface at the die entrance and exit side. The outer surface of the tube contacts the inside of a die when the tube passes through the die. The height of the convex parts decreased at that moment. Hollow sinking suppressed the increase in surface roughness of the inner surface as the outer surface was smoothed in the die. However, due to the formation of surface roughness after leaving the die, there is an overall increasing trend in inner surface roughness. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

18 pages, 7532 KiB

Open AccessArticle

Enhancing of Surface Quality of FDM Moulded Materials through Hybrid Techniques

by Monika Jabłońska and Olga Łastowska

Materials 2024, 17(17), 4250; https://doi.org/10.3390/ma17174250 - 28 Aug 2024

Cited by 3 | Viewed by 1124

Abstract

With the rapid advancement of 3D-printing technology, additive manufacturing using FDM extrusion has emerged as a prominent method in manufacturing. However, it encounters certain limitations, notably in surface quality and dimensional accuracy. Addressing issues related to stability and surface roughness necessitates the integration [...] Read more.

With the rapid advancement of 3D-printing technology, additive manufacturing using FDM extrusion has emerged as a prominent method in manufacturing. However, it encounters certain limitations, notably in surface quality and dimensional accuracy. Addressing issues related to stability and surface roughness necessitates the integration of 3D-printing technology with traditional machining, a strategy known as the hybrid technique. This paper presents a study of the surface geometric parameters and microstructure of plastic parts produced by FDM. Sleeve-shaped samples were 3D-printed from polyethylene terephthalate glycol material using variable layer heights of 0.1 mm and 0.2 mm and then subjected to the turning process with PVD-coated DCMT11T304 turning inserts using variable cutting parameters. The cutting depth was constant at 0.82 mm. Surface roughness values were correlated with the cutting tool feed rate and the printing layer height applied. The selected specimen’s microstructure was studied with a Zeiss EVO MA 15 scanning electron microscope. The roundness was measured with a Keyence VR-6200 3D optical profilometer. The research results confirmed that the additional application of turning, combined with a reduction in the feed rate (0.0506 mm/rev) and the height of the printed layer (0.1 mm), reduced the surface roughness of the sleeve (Ra = 1.94 μm) and increased its geometric accuracy. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

18 pages, 7594 KiB

Open AccessArticle

Development and Implementation of Die Forging Technology Eliminating Flange Welding Operations in Conveyor Driver Forging

by Marek Hawryluk, Sławomir Polak, Marcin Rychlik, Artur Barełkowski, Jakub Jakuć and Jan Marzec

Materials 2024, 17(13), 3281; https://doi.org/10.3390/ma17133281 - 3 Jul 2024

Cited by 2 | Viewed by 1436

Abstract

This article presents research results regarding the development of a new manufacturing technology for an element assigned to belt conveyor flights in the extractive industry through hot die forging (of a forging with a double-sided flange) instead of the currently realized process of [...] Read more.

This article presents research results regarding the development of a new manufacturing technology for an element assigned to belt conveyor flights in the extractive industry through hot die forging (of a forging with a double-sided flange) instead of the currently realized process of producing such an element by welding two flanges onto a sleeve or one flange onto a flange forging. The studies were conducted to design an innovative and low-waste technology, mainly with the use of numerical modelling and simulations, partially based on the current technology of producing a flange forging. Additionally, during the development of the forging process, the aspect of robotization was considered, both in respect of the forging tools and the process of transportation and relocation of forging between the impressions and the forging aggregates. A thermo-mechanical model of the process of producing a belt conveyor flight forging with deformable tools was elaborated by means of the Forge 3NxT program. The results of the conducted numerical modelling made it possible, among other things, to develop models of forging tools ensuring the proper manner of material flow and filling of the impressions, as well as temperature and plastic deformation distributions in the forging and also the detection of possible forging defects. For the technology elaborated this way, the tools were built together with a special instrument for flanging in the metal, and technological tests were performed under industrial conditions. The produced forgings were verified through a measurement of the geometry, by way of 3D scanning, as well as the hardness, which definitively confirmed the properness of the developed technology. The obtained technological test results made it possible to confirm that the elaborated construction, as well as the tool impressions, ensure the possibility of implementing the designed technology with the use of robotization and automatization of the forging process. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

24 pages, 28600 KiB

Open AccessArticle

An Investigation into Sheet-Inconel 718 Forming with Flexible and Metal Tools—Simulation and Experiment

by Maciej Balcerzak, Stanislav Rusz, Radek Čada, Martin Pastrňák, Ondřej Hilšer and Miroslav Greger

Materials 2024, 17(13), 3168; https://doi.org/10.3390/ma17133168 - 28 Jun 2024

Cited by 2 | Viewed by 1063

Abstract

The article presents the results of numerical simulations and experimental tests of plastic forming sheets made from the difficult-to-deform nickel alloy Inconel 718 with a thickness of 1 mm, using punches made from elastomeric materials with hardness 50–90 Shore A and steel dies. [...] Read more.

The article presents the results of numerical simulations and experimental tests of plastic forming sheets made from the difficult-to-deform nickel alloy Inconel 718 with a thickness of 1 mm, using punches made from elastomeric materials with hardness 50–90 Shore A and steel dies. Elastomeric stamps were created in the form of five layers with a diameter of 160 mm. The influence of the hardness of the elastomeric punches on the geometry of the elements obtained was determined. The dies were made from 90MnCrV8 steel with a hardness of over 60 HRC. Their task was to obtain the expected shape of the element while generating various stress states in specific areas of the semi-finished product. The research was carried out using an original device whose operating principle was based on the Guerin method. The shape and dimensions of the elements made from Inconel 718 nickel alloy were determined by optical 3D scanning. The geometry of the drawpiece showed a significant impact of the hardness of the layered elastomer matrices on the degree of shape reproduction. The results obtained from numerical modeling were confirmed by the results of experimental tests. It has been shown that the hardness of the elastomeric material used for punches for plastic forming Inconel 718 nickel alloy sheets should be adapted to the shape of the drawpiece. It was also found that one of the important aspects of plastic forming sheets using the Guerin method is the tendency to obtain a diversified shape of the final elements. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

21 pages, 16346 KiB

Open AccessArticle

Analysis of the Effect of Surface Preparation of Aluminum Alloy Sheets on the Load-Bearing Capacity and Failure Energy of an Epoxy-Bonded Adhesive Joint

by Barbara Ciecińska, Jacek Mucha and Łukasz Bąk

Materials 2024, 17(9), 1948; https://doi.org/10.3390/ma17091948 - 23 Apr 2024

Cited by 2 | Viewed by 1181

Abstract

Surface preparation is an important step in adhesive technology. A variety of abrasive, chemical, or concentrated energy source treatments are used. The effects of these treatments vary due to the variety of factors affecting the final strength of bonded joints. This paper presents [...] Read more.

Surface preparation is an important step in adhesive technology. A variety of abrasive, chemical, or concentrated energy source treatments are used. The effects of these treatments vary due to the variety of factors affecting the final strength of bonded joints. This paper presents the results of an experimental study conducted to determine the feasibility of using fiber laser surface treatments in place of technologically and environmentally cumbersome methods. The effect of surface modification was studied on three materials: aluminum EN AW-1050A and aluminum alloys EN AW-2024 and EN AW-5083. For comparison purposes, joints were made with sandblasted and laser-textured surfaces and those rolled as reference samples for the selected overlap variant, glued with epoxy adhesive. The joints were made with an overlap of 8, 10, 12.5, 14, and 16 mm, and these tests made it possible to demonstrate laser processing as a useful technique to reduce the size of the overlap and achieve even higher load-bearing capacity of the joint compared to sandblasting. A comparative analysis was also carried out for the failure force of the adhesive bond and the failure energy. The results show the efficiency and desirability of using lasers in bonding, allowing us to reduce harmful technologies and reduce the weight of the bonded structure. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

13 pages, 5829 KiB

Open AccessArticle

Experimental Investigation of Load-Bearing Capacity in EN AW-2024-T3 Aluminum Alloy Sheets Strengthened by SPIF-Fabricated Stiffening Rib

by Hassanein I. Khalaf, Raheem Al-Sabur, Andrzej Kubit, Łukasz Święch, Krzysztof Żaba and Vit Novák

Materials 2024, 17(8), 1730; https://doi.org/10.3390/ma17081730 - 10 Apr 2024

Cited by 1 | Viewed by 1427

Abstract

The aluminum strength-to-weight ratio has become a highly significant factor in industrial applications. Placing stiffening ribs along the surface can significantly improve the panel’s resistance to bending and compression in aluminum alloys. This study used single-point incremental forming (SPIF) to fabricate stiffening ribs [...] Read more.

The aluminum strength-to-weight ratio has become a highly significant factor in industrial applications. Placing stiffening ribs along the surface can significantly improve the panel’s resistance to bending and compression in aluminum alloys. This study used single-point incremental forming (SPIF) to fabricate stiffening ribs for 1 mm and 3 mm thick aluminum alloy EN AW-2024-T3 sheets. A universal compression machine was used to investigate sheet deformation. The resulting deformation was examined using non-contact digital image correlation (DIC) based on several high-resolution cameras. The results showed that deformation progressively escalated from the edges toward the center, and the highest buckling values were confined within the non-strengthened area. Specimens with a larger thickness (3 mm) showed better effectiveness against buckling and bending for each applied load: 8 kN or 10 kN. Additionally, the displacement from the sheet surface decreased by 60% for sheets 3 mm thick and by half for sheets 1 mm thick, which indicated that thicker sheets could resist deformation better. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

19 pages, 4678 KiB

Open AccessArticle

Evaluation of High-Frequency Measurement Errors from Turned Surface Topography Data Using Machine Learning Methods

by Przemysław Podulka, Monika Kulisz and Katarzyna Antosz

Materials 2024, 17(7), 1456; https://doi.org/10.3390/ma17071456 - 22 Mar 2024

Cited by 4 | Viewed by 1277

Abstract

Manufacturing processes in industry applications are often controlled by the evaluation of surface topography. Topography, in its overall performance, includes form, waviness, and roughness. Methods of measurement of surface roughness can be roughly divided into tactile and contactless techniques. The latter ones are [...] Read more.

Manufacturing processes in industry applications are often controlled by the evaluation of surface topography. Topography, in its overall performance, includes form, waviness, and roughness. Methods of measurement of surface roughness can be roughly divided into tactile and contactless techniques. The latter ones are much faster but sensitive to external disturbances from the environment. One type of external source error, while the measurement of surface topography occurs, is a high-frequency noise. This noise originates from the vibration of the measuring system. In this study, the methods for reducing high-frequency errors from the results of contactless roughness measurements of turned surfaces were supported by machine learning methods. This research delves into optimizing filtration methods for surface topography measurements through the application of machine learning models, focusing on enhancing the accuracy of surface roughness assessments. By examining turned surfaces under specific machining conditions and employing a variety of digital filters, the study identifies the Gaussian regression filter and spline filter as the most effective methods at a 22.5 µm cut-off. Utilizing neural networks, support vector machines, and decision trees, the research demonstrates the superior performance of SVMs, achieving remarkable accuracy and sensitivity in predicting optimal filtration methods. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

15 pages, 9808 KiB

Open AccessArticle

Characteristics of 2D Ultrasonic Vibration Incremental Forming of a 1060 Aluminum Alloy Sheet

by Yuan Lv, Yifan Wang, Yan Wang, Xixiang Pan, Cong Yi and Meng’en Dong

Materials 2024, 17(6), 1235; https://doi.org/10.3390/ma17061235 - 7 Mar 2024

Cited by 1 | Viewed by 1286

Abstract

Currently, 1060 aluminum alloy is widely applied in the electronics industry, construction, the aerospace field, traffic engineering, decorations, and the consumer goods market for its good chemical, physical, and mechanical properties. In general, excellent processing property is necessary and important for the manufacturing [...] Read more.

Currently, 1060 aluminum alloy is widely applied in the electronics industry, construction, the aerospace field, traffic engineering, decorations, and the consumer goods market for its good chemical, physical, and mechanical properties. In general, excellent processing property is necessary and important for the manufacturing of complicated panels. In this paper, a special 2D ultrasonic vibration incremental forming method is designed to improve its plasticity and mechanical properties. Three kind of processing methods, including traditional single-point incremental forming, longitudinal ultrasonic vibration incremental forming, and 2D ultrasonic vibration incremental forming, are used for the flexible manufacturing of cones and cylindrical cups of 1060 aluminum alloy sheet. Then, micro-hardness tests, residual stress tests, and scanning electron microscopy tests are carried out to probe the changes in micro-structure and mechanical properties and to analyze the effects of different types of ultrasonic vibration on the plasticity and fracture characteristic of 1060 aluminum alloy. It is proven that 2D ultrasonic vibration facilitates the improvement of plasticity and surface qualities of 1060 aluminum alloy better than the other two processing methods. Therefore, the novel 2D ultrasonic vibration incremental forming process possesses substantial application value for the flexible and rapid manufacturing of complicated thin-walled component of aluminum alloy. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

14 pages, 5731 KiB

Open AccessArticle

The Selection of Leveler Parameters Using FEM Simulation

by Sebastian Mróz, Piotr Szota, Tomasz Garstka, Grzegorz Stradomski, Jakub Gróbarczyk and Radosław Gryczkowski

Materials 2024, 17(1), 52; https://doi.org/10.3390/ma17010052 - 22 Dec 2023

Cited by 3 | Viewed by 1589

Abstract

The aim of this research was to select parameters for the roll pre-leveler to provide sheet metal waviness reduction after unwinding from the coil. Straightening parameters were selected based on the results of numerical simulations with the use of an FEM-based computer program. [...] Read more.

The aim of this research was to select parameters for the roll pre-leveler to provide sheet metal waviness reduction after unwinding from the coil. Straightening parameters were selected based on the results of numerical simulations with the use of an FEM-based computer program. The material used for research was a hot-rolled sheet metal of grade S235JR + AR with a thickness of 3 mm and width of 1500 mm after unwinding from the coil. A mathematical model was developed to determine straightening roll arrangements in the pre-leveler. It enabled roll arrangement selection and a straightening scheme to be elaborated. The model’s innovative feature was conducting straightening numerical simulations for the real sheet metal geometric models obtained as a result of 3D laser scanning, which increased the accuracy of the numerical calculations. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

16 pages, 2768 KiB

Open AccessArticle

Research the Dimensional Accuracy of C45 Steel Ring Forgings Produced by Radial Rolling

by Andrzej Gontarz, Piotr Surdacki and Jacek Michalczyk

Materials 2024, 17(1), 3; https://doi.org/10.3390/ma17010003 - 19 Dec 2023

Cited by 4 | Viewed by 1476

Abstract

The rolling process of rings is a commonly used method for producing annular forgings. There are two primary types of this process: radial-axial rolling and radial rolling. This article presents the research results regarding the latter, in which obtaining a product with the [...] Read more.

The rolling process of rings is a commonly used method for producing annular forgings. There are two primary types of this process: radial-axial rolling and radial rolling. This article presents the research results regarding the latter, in which obtaining a product with the assumed dimensions constitutes a major problem. In industrial practice, the process parameters are based on the experience of technologists and/or by trial and error. This is why the authors considered it justified to undertake the research aimed at determining the influence of the main process parameters, that is, preform temperature and tool speed, on the shape and dimensions of the cross-section, which determine the internal and external diameters of the rolled ring. The research was based on numerical simulations and experimental studies. The results obtained proved that the higher the feed speed of the main roll, the greater the change in the cross-sectional height during rolling, and the smaller the cross-sectional deformation (the so-called fishtail). Nevertheless, a higher preform temperature reduces the final height of the ring and reduces cross-section deformation. On the basis of the obtained test results, guidelines for the process design were postulated, considering the influence of temperature and speed parameters on the final dimensions of the forging and the dimensions of the preform. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

20 pages, 4813 KiB

Open AccessArticle

Analysis of the Frictional Performance of AW-5251 Aluminium Alloy Sheets Using the Random Forest Machine Learning Algorithm and Multilayer Perceptron

by Tomasz Trzepieciński, Sherwan Mohammed Najm, Omar Maghawry Ibrahim and Marek Kowalik

Materials 2023, 16(15), 5207; https://doi.org/10.3390/ma16155207 - 25 Jul 2023

Cited by 5 | Viewed by 1674

Abstract

This paper is devoted to the determination of the coefficient of friction (COF) in the drawbead region in metal forming processes. As the test material, AW-5251 aluminium alloys sheets fabricated under various hardening conditions (AW-5251-O, AW-5251-H14, AW-5251-H16 and AW-5251H22) were used. The sheets [...] Read more.

This paper is devoted to the determination of the coefficient of friction (COF) in the drawbead region in metal forming processes. As the test material, AW-5251 aluminium alloys sheets fabricated under various hardening conditions (AW-5251-O, AW-5251-H14, AW-5251-H16 and AW-5251H22) were used. The sheets were tested using a drawbead simulator with different countersample roughness and different orientations of the specimens in relation to the sheet rolling direction. A drawbead simulator was designed to model the friction conditions when the sheet metal passed through the drawbead in sheet metal forming. The experimental tests were carried out under conditions of dry friction and lubrication of the sheet metal surfaces with three lubricants: machine oil, hydraulic oil, and engine oil. Based on the results of the experimental tests, the value of the COF was determined. The Random Forest (RF) machine learning algorithm and artificial neural networks (ANNs) were used to identify the parameters affecting the COF. The R statistical package software version 4.1.0 was used for running the RF model and neural network. The relative importance of the inputs was analysed using 12 different activation functions in ANNs and nine different loss functions in the RF. Based on the experimental tests, it was concluded that the COF for samples cut along the sheet rolling direction was greater than for samples cut in the transverse direction. However, the COF’s most relevant input was oil viscosity (0.59), followed by the average counter sample roughness Ra (0.30) and the yield stress R_p0.2 and strength coefficient K (0.05 and 0.06, respectively). The hard sigmoid activation function had the poorest R² (0.25) and nRMSE (0.30). The ideal run was found after training and testing the RF model (R² = 0.90 ± 0.028). Ra values greater than 1.1 and R_p0.2 values between 105 and 190 resulted in a decreased COF. The COF values dropped to 9–35 for viscosity and 105–190 for R_p0.2, with a gap between 110 and 130 when the oil viscosity was added. The COF was low when the oil viscosity was 9–35, and the Ra was 0.95–1.25. The interaction between K and the other inputs, which produces a relatively limited range of reduced COF values, was the least relevant. The COF was reduced by setting the R_p0.2 between 105 and 190, the Ra between 0.95 and 1.25, and the oil viscosity between 9 and 35. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

14 pages, 11002 KiB

Open AccessArticle

The Influence of Tool Geometry on the Mechanical Properties and the Microstructure of AA6061-T6 Aluminum Alloy Friction Stir Spot Welding

by Amir Alkhafaji, Daniel Camas, Pablo Lopez-Crespo and Hayder Al-Asadi

Materials 2023, 16(11), 4135; https://doi.org/10.3390/ma16114135 - 1 Jun 2023

Cited by 9 | Viewed by 1863

Abstract

In this work, the influence of the tool geometry on friction stir spot welding (FSSW) was studied on sheets made of AA6061-T6 aluminum alloy. Four different AISI H13 tools with simple cylindrical and conical pin profiles and 12 mm and 16 mm shoulder [...] Read more.

In this work, the influence of the tool geometry on friction stir spot welding (FSSW) was studied on sheets made of AA6061-T6 aluminum alloy. Four different AISI H13 tools with simple cylindrical and conical pin profiles and 12 mm and 16 mm shoulder diameters were used to perform the FSSW joints. Sheets of 1.8 mm thickness were used during the experimental work to prepare the lap-shear specimens. The FSSW joints were performed at room temperature. For each joining condition, four specimens were carried out. Three specimens were used to find the value of the average tensile shear failure load (TSFL), while the fourth one was used to examine the micro-Vickers hardness profile and to observe the microstructure of the cross-section of the FSSW joints. The investigation concluded that higher mechanical properties corresponding to the finer microstructure were obtained by the conical pin profile and the higher shoulder diameter compared with the specimens performed using the cylindrical pin tool and lower shoulder diameter due to the higher strain hardening and the higher frictional heat generation, respectively. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

31 pages, 9242 KiB

Open AccessArticle

Modelling Fibre-Reinforced Concrete for Predicting Optimal Mechanical Properties

by Hamad Hasan Zedan Khalel and Muhammad Khan

Materials 2023, 16(10), 3700; https://doi.org/10.3390/ma16103700 - 12 May 2023

Cited by 6 | Viewed by 3118

Abstract

Fibre-reinforced cementitious composites are highly effective for construction due to their enhanced mechanical properties. The selection of fibre material for this reinforcement is always challenging as it is mainly dominated by the properties required at the construction site. Materials like steel and plastic [...] Read more.

Fibre-reinforced cementitious composites are highly effective for construction due to their enhanced mechanical properties. The selection of fibre material for this reinforcement is always challenging as it is mainly dominated by the properties required at the construction site. Materials like steel and plastic fibres have been rigorously used for their good mechanical properties. Academic researchers have comprehensively discussed the impact and challenges of fibre reinforcement to obtain optimal properties of resultant concrete. However, most of this research concludes its analysis without considering the collective influence of key fibre parameters such as its shape, type, length, and percentage. There is still a need for a model that can consider these key parameters as input, provide the properties of reinforced concrete as output, and facilitate the user to analyse the optimal fibre addition per the construction requirement. Thus, the current work proposes a Khan Khalel model that can predict the desirable compressive and flexural strengths for any given values of key fibre parameters. The accuracy of the numerical model in this study, the flexural strength of SFRC, had the lowest and most significant errors, and the MSE was between 0.121% and 0.926%. Statistical tools are used to develop and validate the model with numerical results. The proposed model is easy to use but predicts compressive and flexural strengths with errors under 6% and 15%, respectively. This error primarily represents the assumption made for the input of fibre material during model development. It is based on the material’s elastic modulus and hence neglects the plastic behaviour of the fibre. A possible modification in the model for considering the plastic behaviour of the fibre will be considered as future work. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

18 pages, 6445 KiB

Open AccessArticle

Improving the Surface Integrity of 316L Steel in the Context of Bioimplant Applications

by Krzysztof Szwajka, Joanna Zielińska-Szwajka and Tomasz Trzepieciński

Materials 2023, 16(9), 3460; https://doi.org/10.3390/ma16093460 - 28 Apr 2023

Cited by 11 | Viewed by 1683

Abstract

Bioimplants should meet important surface integrity criteria, with the main goal of the manufacturing process to improve wear and corrosion resistance properties. This requires a special approach at the cutting stage. During this research, the impact of the cutting parameters on improving the [...] Read more.

Bioimplants should meet important surface integrity criteria, with the main goal of the manufacturing process to improve wear and corrosion resistance properties. This requires a special approach at the cutting stage. During this research, the impact of the cutting parameters on improving the surface integrity of AISI 316L steel was evaluated. In this context of bioimplant applications, the mean roughness Sa value was obtained in the range of 0.73–4.19 μm. On the basis of the results obtained, a significant effect was observed of both the cutting speed and the feed rate on changes in the microstructure of the near-surface layer. At a cutting speed of 150 m/min, the average grain size was approximately 31 μm. By increasing the cutting speed to 200 m/min, the average grain size increased to approximately 52 μm. The basic austenitic microstructure of AISI 316L steel with typical precipitation of carbides on the grain boundaries was refined at the near-surface layer after the machining process. Changing the cutting speed determined the hardness of the treated and near-surface layers. The maximum value of hardness is reached at a depth of 20 μm and decreases with the depth of measurement. It was also noted that at a depth of up to 240 μm, the maximum hardness of 270–305 HV1 was reached, hence the height of the machining impact zone can be determined, which is approximately 240 μm for almost all machining conditions. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

16 pages, 7178 KiB

Open AccessArticle

Role of Dynamic Response in Inclined Transverse Crack Inspection for 3D-Printed Polymeric Beam with Metal Stiffener

by Arturo Francese, Muhammad Khan and Feiyang He

Materials 2023, 16(8), 3095; https://doi.org/10.3390/ma16083095 - 14 Apr 2023

Cited by 3 | Viewed by 1871

Abstract

This paper aims to quantify the relationship between the dynamic response of 3D-printed polymeric beams with metal stiffeners and the severity of inclined transverse cracks under mechanical loading. Very few studies in the literature have focused on defects starting from bolt holes in [...] Read more.

This paper aims to quantify the relationship between the dynamic response of 3D-printed polymeric beams with metal stiffeners and the severity of inclined transverse cracks under mechanical loading. Very few studies in the literature have focused on defects starting from bolt holes in light-weighted panels and considered the defect’s orientation in an analysis. The research outcomes can be applied to vibration-based structure health monitoring (SHM). In this study, an acrylonitrile butadiene styrene (ABS) beam was manufactured through material extrusion and bolted to an aluminium 2014-T615 stiffener as the specimen. It simulated a typical aircraft stiffened panel geometry. The specimen had seeded and propagated inclined transverse cracks of different depths (1/1.4 mm) and orientations (0°/30°/45°). Then, their dynamic response was investigated numerically and experimentally. The fundamental frequencies were measured with an experimental modal analysis. The numerical simulation provided the modal strain energy damage index (MSE-DI) to quantify and localise the defects. Experimental results showed that the 45° cracked specimen presented the lowest fundamental frequency with a decreased magnitude drop rate during crack propagation. However, the 0° cracked specimen generated a more significant frequency drop rate with an increased crack depth ratio. On the other hand, several peaks were presented at various locations where no defect was present in the MSE-DI plots. This suggests that the MSE-DI approach for assessing damage is unsuitable for detecting cracks beneath stiffening elements due to the restriction of the unique mode shape at the crack’s location. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

29 pages, 22101 KiB

Open AccessArticle

Minimizing the Main Strains and Thickness Reduction in the Single Point Incremental Forming Process of Polyamide and High-Density Polyethylene Sheets

by Nicolae Rosca, Mihaela Oleksik, Liviu Rosca, Eugen Avrigean, Tomasz Trzepieciński, Sherwan Mohammed Najm and Valentin Oleksik

Materials 2023, 16(4), 1644; https://doi.org/10.3390/ma16041644 - 16 Feb 2023

Cited by 8 | Viewed by 2181

Abstract

Polymeric materials are increasingly used in the automotive industry, aeronautics, medical device industry, etc. due to their advantage of providing good mechanical strength at low weight. The incremental forming process for polymeric materials is gaining increasing importance because of the advantages it offers: [...] Read more.

Polymeric materials are increasingly used in the automotive industry, aeronautics, medical device industry, etc. due to their advantage of providing good mechanical strength at low weight. The incremental forming process for polymeric materials is gaining increasing importance because of the advantages it offers: relatively complex parts can be produced at minimum cost without the need for complex and expensive dies. Knowing the main strains and especially the thickness reduction is particularly important as it directly contributes to the mechanical strength of the processed parts, including in operation. For the design of experiments, the Taguchi method was chosen, with an L₁₈ orthogonal array obtained by varying the material on two levels (polyamide and polyethylene) and the other three parameters on three levels: punch diameter (6 mm, 8 mm and 10 mm), wall angle (50°, 55° and 60°) and step down (0.5 mm, 0.75 mm and 1 mm). The output parameters were strain in the x direction, strain in the y direction, major strain, minor strain, shear angle and thickness reduction. Two analyses were conducted: signal-to-noise ratio analysis with the smaller-is-better condition and analysis of variance. The optimum values for which the thickness was reduced were the following: wall angle of 50°, punch diameter of 10 mm and step down of 0.75 mm. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

Review

Jump to: Research

20 pages, 7246 KiB

Open AccessReview

Durability of Forging Tools Used in the Hot Closed Die Forging Process—A Review

by Grzegorz Ficak, Aneta Łukaszek-Sołek and Marek Hawryluk

Materials 2024, 17(22), 5407; https://doi.org/10.3390/ma17225407 - 5 Nov 2024

Cited by 2 | Viewed by 2075

Abstract

The article presents the classification of the wear mechanisms of forging tools. The durability of dies can be enhanced through a variety of methods, including the selection of appropriate hot working tool steel, the application of effective heat treatment, the utilization of advanced [...] Read more.

The article presents the classification of the wear mechanisms of forging tools. The durability of dies can be enhanced through a variety of methods, including the selection of appropriate hot working tool steel, the application of effective heat treatment, the utilization of advanced surface engineering techniques, and the incorporation of lubricating and cooling agents. Two popular methods of tool regeneration, such as re-profiling and laser regeneration, are presented. The issue of numerical wear prediction based on the Archard model, the correlation of this model with experimental results, low-cycle fatigue (HTLCF), and an alternative method based on artificial neural networks are discussed. The paper aims to present currently known wear mechanisms and the methods of increasing and predicting tool durability. Full article

(This article belongs to the Special Issue Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Forming Technologies and Mechanical Properties of Advanced Materials - 2nd Volume

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (21 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI