Research

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18 pages, 7551 KiB

Open AccessArticle

Enhancing Dimensional Accuracy in Budget-Friendly 3D Printing through Solid Model Geometry Tuning and Its Use in Rapid Casting

by Barun Haldar

Machines 2023, 11(11), 1020; https://doi.org/10.3390/machines11111020 - 12 Nov 2023

Cited by 1 | Viewed by 1484

Abstract

Achieving precise dimensional accuracy and improving surface quality are the primary research and development objectives in the engineering and industrial applications of 3D printing (3DP) technologies. This experimental study investigates the pivotal role of solid model geometry tuning in enhancing the dimensional accuracy [...] Read more.

Achieving precise dimensional accuracy and improving surface quality are the primary research and development objectives in the engineering and industrial applications of 3D printing (3DP) technologies. This experimental study investigates the pivotal role of solid model geometry tuning in enhancing the dimensional accuracy of affordable 3D printing technologies, with a specific focus on economical engineering applications. This experiment utilises low-cost Material Extrusion/Fused Filament Fabrication (FFF) and Stereolithography (SLA)/Digital Light Processing (DLP) 3D-printed patterns for the meticulous measurement of errors in the X, Y, and Z directions. These errors are then used to refine subsequent solid models, resulting in a marked improvement in dimensional accuracy (i.e., 0.15%, 0.33%, and 2.16% in the X, Y, and Z directions, respectively) in the final DLP 3D-printed parts. The study also derives and experimentally validates a novel and simple mathematical model for tuning the solid model based on the calculated linear directional errors (

e_{i}

,

e_{j}

, and

e_{k}

). The developed mathematical model offers a versatile approach for achieving superior dimensional accuracy in other 3D printing processes. Medium-sized (4 to 10 cm) wax-made DLP- and PLA-made patterns are used to test the ceramic mould-building capacity for rapid casting (RC), where the FFF-based 3D-printed (hollow inside) pattern favours successful RC. This work comprehensively addresses the critical challenges encountered in low-cost DLP and FFF processes and their scopes in engineering applications. It provides novel suggestions and answers to improve the effectiveness, quality, and accuracy of the FFF 3D printing process for future applications in RC. Full article

(This article belongs to the Special Issue High Performance and Hybrid Manufacturing Processes)

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13 pages, 8380 KiB

Open AccessArticle

Parametric Modeling of Curvic Couplings and Analysis of the Effect of Coupling Geometry on Contact Stresses in High-Speed Rotation Applications

by Chara Efstathiou, Ioanna Tsormpatzoglou and Nikolaos Tapoglou

Machines 2023, 11(8), 822; https://doi.org/10.3390/machines11080822 - 10 Aug 2023

Viewed by 2133

Abstract

Curvic couplings are used in applications demanding high positional accuracy and high torque transmission; therefore, improving their design and enhancing their load-carrying capacity is crucial. This study introduced the kinematic model Curvic3D, which was developed to produce the accurate geometry of both members [...] Read more.

Curvic couplings are used in applications demanding high positional accuracy and high torque transmission; therefore, improving their design and enhancing their load-carrying capacity is crucial. This study introduced the kinematic model Curvic3D, which was developed to produce the accurate geometry of both members of a curvic coupling using a CAD system. The model enabled the complete parametrization and customization of the coupling design using important geometric parameters. The couplings produced using Curvic3D were then imported into a finite element analysis model also developed as part of this study. A detailed analysis of the stresses developed on the teeth of the concave and convex parts provided information about the behavior of the coupling under different loading conditions. Finally, a series of geometric parameters, such as the number of teeth, the number of half pitches, the root fillet radius, and gable angle were examined as to their influence on the load-carrying capacity of the curvic coupling. The study concluded that all the examined parameters have a significant effect on the tooth flank and root area stresses. Full article

(This article belongs to the Special Issue High Performance and Hybrid Manufacturing Processes)

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28 pages, 20500 KiB

Open AccessArticle

Experimental Study and 3D Optimization of Small-Scale Solar-Powered Radial Turbine Using 3D Printing Technology

by Ahmed M. Daabo, Ali Abdelhafeez Hassan, Muhammad Anser Bashir, Hudhaifa Hamza, Shahad Salim, Aisha Koprulu, Tawfik Badawy, Saad Mahmoud and Raya Al-Dadah

Machines 2023, 11(8), 817; https://doi.org/10.3390/machines11080817 - 09 Aug 2023

Viewed by 906

Abstract

Small-Scale Turbines (SSTs) are among the most important energy-extraction-enabling technologies in domestic power production systems. However, owing to centrifugal forces, the high rotating speed of SSTs causes excessive strains in the aerofoil portions of the turbine blades. In this paper, a structural performance [...] Read more.

Small-Scale Turbines (SSTs) are among the most important energy-extraction-enabling technologies in domestic power production systems. However, owing to centrifugal forces, the high rotating speed of SSTs causes excessive strains in the aerofoil portions of the turbine blades. In this paper, a structural performance analysis is provided by combining Finite Element Methods (FEM) with Computational Fluid Dynamics (CFD). The primary objective was to examine the mechanical stresses of a Small-Scale Radial Turbine (SSRT) constructed utilizing 3D printing technology and a novel plastic material, RGD 525, to construct a SSRT model experimentally. After introducing a suitable turbine aerodynamics model, the turbine assembly and related loads were translated to a structural model. Subsequently, a structural analysis was conducted under various loading situations to determine the influence of different rotational speed values and blade shapes on the stress distribution and displacement. Maximum von Mises and maximum main stresses are significantly affected by both the rotor rotational speed and the working fluid input temperature, according to the findings of this research. The maximum permitted deformation, on the other hand, was more influenced by rotational speed, while the maximum allowable fatigue life was more influenced by rotating speed and fluid intake temperature. Also, the region of the tip shroud in the rotor had greater deflection values of 21% of the blade tip width. Full article

(This article belongs to the Special Issue High Performance and Hybrid Manufacturing Processes)

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19 pages, 8698 KiB

Open AccessArticle

Non-Destructive Disassembly of Interference Fit under Wear Conditions for Sustainable Remanufacturing

by Ho Lam Au-Yeung, Sabbah Ataya, Hany Hassanin, Mahmoud Ahmed El-Sayed, Mahmoud Ahmadein, Naser A. Alsaleh, Mohamed M. Z. Ahmed and Khamis Essa

Machines 2023, 11(5), 538; https://doi.org/10.3390/machines11050538 - 10 May 2023

Viewed by 1713

Abstract

Remanufacturing has been gaining increasing attention in the last few years as a part of green engineering. It is the process of restoring the original specifications of a given product utilizing a combination of new, repaired, and old parts. The present study investigates [...] Read more.

Remanufacturing has been gaining increasing attention in the last few years as a part of green engineering. It is the process of restoring the original specifications of a given product utilizing a combination of new, repaired, and old parts. The present study investigates non-destructive disassembly of an interference fit pin-hub joint to enable the reuse of worn parts with the same loading capacity. The aim is to reduce the disassembly force while preventing plastic deformation and frictional damage on the contact surface to avoid fretting failure and enable further coating. A finite element model of a shaft/hub interference fit was developed, taking into account two cases of damage to the mating parts: deformation and corrosion. The results indicate that thermal disassembly is effective in reducing breaking force by 50% in deformed joints, whereas vibration waves are more suitable for corroded parts with increased friction. In addition, applying a low-frequency oscillation force to the axis of disassembly reduces the pulling out force by 5% and plastic deformation by 99% due to acoustic softening effects. Furthermore, using a heat flux simultaneously with vibration decreases the breaking force by 85%, indicating the higher effectiveness of thermal-aided disassembly and vibration-assisted disassembly in reducing the breaking force of corroded parts with increased friction. This study provides remanufacturing designers with efficient tools to weaken the interference fit and decrease the disconnecting force, ultimately reducing the cost and time required for the disassembly process. Full article

(This article belongs to the Special Issue High Performance and Hybrid Manufacturing Processes)

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20 pages, 7012 KiB

Open AccessArticle

Effects of Tool Edge Geometry and Cutting Conditions on the Performance Indicators in Dry Turning AISI 1045 Steel

by Adel T. Abbas, Magdy M. El Rayes, Abdulhamid A. Al-Abduljabbar, Adham E. Ragab, Faycal Benyahia and Ahmed Elkaseer

Machines 2023, 11(3), 397; https://doi.org/10.3390/machines11030397 - 18 Mar 2023

Cited by 3 | Viewed by 1531

Abstract

This article presents an experimental investigation and statistical analysis of the effects of cutting conditions on the machining performance of AISI 1045 steel using a wiper-shaped insert. Experimental findings are used to compare the machining performance obtained using wiper inserts with those obtained [...] Read more.

This article presents an experimental investigation and statistical analysis of the effects of cutting conditions on the machining performance of AISI 1045 steel using a wiper-shaped insert. Experimental findings are used to compare the machining performance obtained using wiper inserts with those obtained using conventional round-nose inserts as recently reported in the literature. In addition, the effects of process conditions, namely cutting speed, feed rate, and depth of cut, are analyzed in order to obtain optimum conditions for both types of inserts. The goal is to achieve the optimal machining outcomes: minimum surface roughness, resultant cutting force, and cutting temperature, but maximum material removal rate. A full factorial design was followed to conduct the experimental trials, while ANOVA was utilized to estimate the effect of each factor on the process responses. A desirability function optimization tool was used to optimize the studied responses. The results reveal that the optimum material removal rate for wiper-shaped inserts is 67% more than that of conventional inserts, while maintaining a 0.7 µm surface roughness value. The superior results obtained with wiper-shaped inserts allow wiper tools to use higher feed rates, resulting in larger material removal rates while obtaining the same surface quality. Full article

(This article belongs to the Special Issue High Performance and Hybrid Manufacturing Processes)

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21 pages, 7302 KiB

Open AccessArticle

DLP of Translucent Alumina: In-Depth Investigation on Slurry Development and Debinding Regimes

by Michele De Lisi, Chang Shu, Usama M. Attia and Khamis Essa

Machines 2023, 11(3), 321; https://doi.org/10.3390/machines11030321 - 23 Feb 2023

Cited by 1 | Viewed by 1671

Abstract

Exploring the feasibility of producing near-net-shape components with advanced properties and geometrical features via 3D printing has incrementally become the research focus of various studies. Digital light processing (DLP) technology can manufacture complex-structured components for various technical applications. The aims of this research [...] Read more.

Exploring the feasibility of producing near-net-shape components with advanced properties and geometrical features via 3D printing has incrementally become the research focus of various studies. Digital light processing (DLP) technology can manufacture complex-structured components for various technical applications. The aims of this research were to investigate Al₂O₃ ceramic slurry preparation procedures to identify the ideal components to add to an in-house-developed ceramic slurry, to determine the optimal DLP printing parameters and conditions while understanding their effect on the green part properties and to evaluate the appropriate debinding regime to achieve fully dense crack-free fired parts capable of exhibiting translucent behaviours. The slurry obtained from the ball-milled powder at 800 rpm for 1 h, together with 2 wt.% BYK-145 as a dispersant and the highest achievable solid loading of 85 wt.%, showed the desired rheological and photopolymerisation properties. Full-factorial design of experiments (DOE) was employed to study the impact of the printing parameters on the density and the dimensions of the samples. Different debinding regimes were investigated and it was proven that the lowest debinding heat rate (0.2 °C/min) and longer holding times helped to reduce defects and promote densification (>99.0%), providing optimal grounds to obtain translucent fired parts. Full article

(This article belongs to the Special Issue High Performance and Hybrid Manufacturing Processes)

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16 pages, 5829 KiB

Open AccessArticle

Selection of Constitutive Material Model for the Finite Element Simulation of Pressure-Assisted Single-Point Incremental Forming

by Ali Abdelhafeez Hassan, Gökhan Küçüktürk, Hurcan Volkan Yazgin, Hakan Gürün and Duran Kaya

Machines 2022, 10(10), 941; https://doi.org/10.3390/machines10100941 - 17 Oct 2022

Cited by 2 | Viewed by 1553

Abstract

Pressure-assisted single-point incremental forming (PA-SPIF) is one of the emerging forming techniques for sheet metals that have been the subject of rigorous research over the past two decades. Understanding of its forming mechanisms and capabilities is growing as a result. Open gaps are [...] Read more.

Pressure-assisted single-point incremental forming (PA-SPIF) is one of the emerging forming techniques for sheet metals that have been the subject of rigorous research over the past two decades. Understanding of its forming mechanisms and capabilities is growing as a result. Open gaps are still present in material constitutive modelling for accurate numerical predictions and finite-element simulations as the characteristics of localised deformation behaviour in SPIF are different from those of conventional sheet metal forming. The current investigation focused on the comparison of three different material models for the finite-element analysis of PA-SPIF of cold-rolled, dual-phase steel DP600. Experimental trials using different fluid pressures showed good agreement with simulation results with discrepancies in deformed blank thickness and shape geometry predictions of 3–11% and 10–21%, respectively. Within the tested materials and range of parameters, the fracture-forming-limit diagram (FFLD) material model was identified to be of superior accord with experiments. Full article

(This article belongs to the Special Issue High Performance and Hybrid Manufacturing Processes)

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19 pages, 2813 KiB

Open AccessArticle

Interdependence of Technical and Technological Parameters in Polymer Ultrasonic Welding

by Dubravko Rogale, Siniša Fajt, Snježana Firšt Rogale and Željko Knezić

Machines 2022, 10(10), 845; https://doi.org/10.3390/machines10100845 - 23 Sep 2022

Cited by 1 | Viewed by 1472

Abstract

The welding of foils, textiles, and textile composites made of thermoplastic polymer materials using machines with an ultrasonic rotary sonotrode is a high-tech welding technique. Many authors have dealt with only a few parameters in earlier papers, mainly mentioning the speed, i.e., the [...] Read more.

The welding of foils, textiles, and textile composites made of thermoplastic polymer materials using machines with an ultrasonic rotary sonotrode is a high-tech welding technique. Many authors have dealt with only a few parameters in earlier papers, mainly mentioning the speed, i.e., the welding time, and the power of the ultrasonic generator. In this paper, the acoustic model of ultrasonic welding is defined. Based on the model, a group of 44 different parameters important for ultrasonic welding of polymer materials has been summarised, namely 12 parameters of the polymer material, 11 general acoustic and electroacoustic parameters, and 21 technical parameters depending on the ultrasonic machine. Based on this, a comprehensive mathematical derivation was carried out, linking parameter groups with other findings from acoustics, thermodynamics of polymers, and technical and technological parameters of welding polymer materials. The most important parameters are the power of the ultrasonic generator and the welding time, which in practice are adjusted to produce a solid weld. The method of measuring the amplitude of the sonotrode using a photonic sensor is presented in this paper. For 42 groups of welds done at various welding speeds and ultrasonic generator powers, the breaking forces of ultrasonic welds were measured. There are illustrations of power dependence and breaking forces. The accuracy of the mathematical model was confirmed by comparison with the calculation results based on the findings of these measurements. Full article

(This article belongs to the Special Issue High Performance and Hybrid Manufacturing Processes)

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Review

Jump to: Research

25 pages, 3106 KiB

Open AccessReview

Elucidating Powder-Mixed Electric Discharge Machining Process, Applicability, Trends and Futuristic Perspectives

by Iqtidar Ahmed Gul, Ahmad Majdi Abdul-Rani, Md Al-Amin and Elhuseini Garba

Machines 2023, 11(3), 381; https://doi.org/10.3390/machines11030381 - 13 Mar 2023

Cited by 3 | Viewed by 2134

Abstract

Since the inception of electric discharge machining (EDM), it has facilitated the production industries, for instance, die & mold, automotive, aerospace, etc., by providing an effective solution for machining hard-to-cut materials and intricate geometries. However, achieving high machining rates and a fine surface [...] Read more.

Since the inception of electric discharge machining (EDM), it has facilitated the production industries, for instance, die & mold, automotive, aerospace, etc., by providing an effective solution for machining hard-to-cut materials and intricate geometries. However, achieving high machining rates and a fine surface finish is an inherent issue with the traditional EDM process. The emergence of the powder mixed electric discharge machining (PMEDM) process has not only provided the opportunity for enhancing productivity and surface finish but also opened a window for its potential application in surface modification/coating of biomaterials. The process incorporates simultaneous machining and coating of bioimplants, i.e., lacking in the already available chemical and physical coating methods while requiring costly post-treatment procedures. This study comprehends the influence of powder characteristics and EDM process parameters on the performance parameters. The impact of tool electrodes and additive powders on the machined and coated surface of commonly used biomaterials. Furthermore, the study depicts the most frequently used methods for optimizing the PMEDM process, future research directions, challenges, and research trends over the past decade. Full article

(This article belongs to the Special Issue High Performance and Hybrid Manufacturing Processes)

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