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Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties

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A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Advanced Composites".

Deadline for manuscript submissions: closed (20 December 2022) | Viewed by 20133

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Dr. Christophe Pinna

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Department of Mechanical Engineering, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
Interests: microstructure characterization; microstructure modelling; damage modelling; finite element modelling; fatigue/fracture; full-field strain measurements
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Dear Colleagues,

Materials manufacturing processes are constantly evolving with the emergence of new technologies, such as additive manufacturing or automated fibre placement for composites, to name a few, introduced to meet the need for better performance and innovation in various industrial sectors. Whether traditional manufacturing processes make new advancements or new technologies are developed, fundamental research is needed to understand the effect of process parameters on material microstructures and directly related mechanical properties of final products. This knowledge is indeed essential for the optimisation of manufacturing processes and the development of next-generation materials in order to meet industrial demand. The latest developments in state-of-the-art experimental characterisation techniques and multiscale modelling offer new routes for developing this understanding. Artificial intelligence with data-driven models and multiobjective optimisation techniques are also increasingly used for robust optimisation of material processes with direct industrial relevance in the age of digital manufacturing.

This forthcoming Special Issue of Materials is focused on publishing the latest research in this very active field at the forefront of new materials and process development. Research articles, communications, or reviews relating advanced manufacturing processes–microstructure–mechanical properties for metals and composites are welcome. It is therefore my pleasure to invite you to contribute to this Special Issue.

Dr. Christophe Pinna
Guest Editor

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Keywords

manufacturing process
microstructure
mechanical properties
metals
composites
characterisation techniques
multiscale modelling
optimisation
data-driven models
artificial intelligence

Published Papers (13 papers)

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Research

12 pages, 3973 KiB

Open AccessArticle

Effects of Melt Hydrogenation on the Microstructure Evolution and Hot Deformation Behavior of TiBw/Ti-6Al-4V Composites

by Hui Yan, Liang Wang, Xiaoming Wang, Botao Jiang, Hongcan Liu, Binbin Wang, Liangshun Luo, Yanqing Su, Jingjie Guo and Hengzhi Fu

Materials 2023, 16(6), 2496; https://0-doi-org.brum.beds.ac.uk/10.3390/ma16062496 - 21 Mar 2023

Cited by 3 | Viewed by 1031

Abstract

In this study, Ti-6Al-4V matrix composites reinforced with TiB ceramic whiskers were in situ synthesized and hydrogenated using the melt hydrogenation technique (MHT). The effects of MHT on the microstructure evolution and hot compression behavior of the composites were investigated by optical microscopy (OM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). Hot compression tests were performed at strain rates of 0.1/s, 0.01/s, and 0.001/s and temperatures of 800 °C, 850 °C, and 900 °C; the hot workability of composites significantly improved after hydrogenation, for example, the 900 °C peak flow stress of hydrogenated composites (43 MPa) decreased by 53.76% compared with that of unhydrogenated ones (93 MPa) at a strain rate of 0.01/s. Microstructural observations show that MHT can effectively facilitate the dispersion of TiB whiskers and induce the α/β lath refinement of the matrix in our as-cast hydrogenated composite. During hot compression, MHT effectively promoted the as-cast composite microstructure refinement, accelerated the dynamic recrystallization (DRX) generation, and reduced the stress concentration at the interface between the reinforcement and matrix; in turn, the hydrogenated composites presented low peak stress during hot compression. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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13 pages, 6793 KiB

Open AccessArticle

Comparative Study on the Densification, Microstructure and Properties of WC-10(Ni, Ni/Co) Cemented Carbides Using Electroless Plated and Coprecipitated Powders

by Haoli Jiang, Jing Tong, Zhaoqing Zhan, Zhanhu Yao, Songbai Yu, Fanlu Min, Congxu Wang, Jacques Guillaume Noudem and Jianfeng Zhang

Materials 2023, 16(5), 1977; https://0-doi-org.brum.beds.ac.uk/10.3390/ma16051977 - 28 Feb 2023

Cited by 1 | Viewed by 1156

Abstract

More and more attention is being paid to the influence of powder mixing on the mechanical properties and corrosion resistance of WC-based cemented carbides. In this study, WC was mixed with Ni and Ni/Co, respectively, by chemical plating and co-precipitated-hydrogen reduction, which are labelled as WC-Ni^EP, WC-Ni/Co^EP, WC-Ni^CP and WC-Ni/Co^CP, respectively. After being densified in a vacuum, the density and grain size of CP were denser and finer than those of EP were. Simultaneously, the better mechanical properties of flexural strength (1110 MPa) and impact toughness (33 kJ/m²) were obtained by WC-Ni/Co^CP due to the uniform distribution of WC and binding phase and solid solution enhancement of the Ni-Co alloy. In addition, the lowest self-corrosion current density of 8.17 × 10⁻⁷ A·cm⁻², a self-corrosion potential of −0.25 V and the biggest corrosion resistance of 1.26 × 10⁵ Ω in 3.5 wt % NaCl solution were obtained by WC-Ni^EP because of the presence of the Ni-Co-P alloy. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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19 pages, 7057 KiB

Open AccessArticle

Hot Deformation Behavior and Simulation of Hot-Rolled Damage Process for Fine-Grained Pure Tungsten at Elevated Temperatures

by Yongqi Lv, Siqi Zhao, Tao Liu, Huichao Cheng, Jinglian Fan and Yuanchun Huang

Materials 2022, 15(22), 8246; https://0-doi-org.brum.beds.ac.uk/10.3390/ma15228246 - 20 Nov 2022

Cited by 2 | Viewed by 1360

Abstract

Fine-grained pure tungsten fabricated by a sol drying reduction low-temperature sintering method and hot isothermal compression tests were performed by using the Gleeble 3800 thermo mechanical simulator at deformation temperatures from 1273 K to 1473 K and strain rates from 0.001 s⁻¹ to 1 s⁻¹. In addition, the constitutive equation was established by least square method combined with the Zerilli–Armstrong model, and the hot deformation behavior was discussed. Moreover, based on constitutive equation, the influence of the rolling process and its parameters on temperature, strain, density and rolling force in the hot rolling process was investigated at elevated temperature by the finite element model (FEM). Furthermore, the form of rolling damage and its formation mechanism were analyzed. Results showed the grains of pure tungsten are dense, irregular polyhedral spherical and very fine, and the average grain size is about 5.22 μm. At a high strain rate, the flow stress increases rapidly with the increase in strain, while the stress–strain curve shows a flattening trend in the tested strain rate range with increasing temperature, and no flow stress peak exists, showing obvious dynamic recovery characteristics. Furthermore, the FEM simulation showed that compared with the rolling temperature, the reduction has a greater influence on the temperature, stress–strain field and its distribution. There are three kinds of damage in the hot rolling process: transverse cracks, longitudinal cracks and side cracks, which are attributed to the competition between additional stress caused by uneven deformation and material strength. Moreover, the control method of hot rolling defects had been preliminarily proposed. These results should be of relevance for the optimum design of the hot rolling process of pure tungsten. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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17 pages, 5297 KiB

Open AccessArticle

Optimization of Bobbin Tool Friction Stir Processing Parameters of AA1050 Using Response Surface Methodology

by Ibrahim Albaijan, Mohamed M. Z. Ahmed, Mohamed M. El-Sayed Seleman, Kamel Touileb, Mohamed I. A. Habba and Ramy A. Fouad

Materials 2022, 15(19), 6886; https://0-doi-org.brum.beds.ac.uk/10.3390/ma15196886 - 04 Oct 2022

Cited by 9 | Viewed by 1443

Abstract

The current research designed a statistical model for the bobbin tool friction stir processing (BT-FSP) of AA1050 aluminum alloy using the Response Surface Method (RSM). The analysis studied the influence of tool travel speeds of 100, 200, and 300 mm/min and different pin geometries (triangle, square, and cylindrical) at a constant tool rotation speed (RS) of 600 rpm on processing 8 mm thickness AA1050. The developed mathematical model optimizes the effect of the applied BT-FSP parameters on machine torque, processing zone (PZ) temperature, surface roughness, hardness values, and ultimate tensile strength (UTS). The experimental design is based on the Face Central Composite Design (FCCD), using linear and quadratic polynomial equations to develop the mathematical models. The results show that the proposed model adequately predicts the responses within the processing parameters, and the pin geometry is the most influential parameter during the BT-FSP of AA1050. The analysis of variance exhibit that the developed mathematical models can effectively predict the values of the machine torque, PZ temperature, surface roughness, hardness, and UTS with a confidence level of over 95% for the AA1050 BT-FSP. The optimization process shows that the optimum parameters to attain the highest mechanical properties in terms of hardness and tensile strength at the lowest surface roughness and machine torque are travel speed (TS) of 200 mm/min using cylindrical (Cy) pin geometry at the constant RS of 600 rpm. The PZ temperature of the processed specimens decreased with increasing TS at different pin geometries. Meanwhile, the surface roughness of the processed passes and machine torque increased with increasing the TS at different pin geometries. Increasing TS from 100 to 300 mm/min increases the hardness values of the processed materials using different pin geometries. The highest UTS of 79 MPa for the processed specimens was attained at the TS of 200 mm/min and RS of 600 rpm using the Cy pin geometry. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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25 pages, 7633 KiB

Open AccessArticle

Microstructural Evolution during Accelerated Tensile Creep Test of ZK60/SiC_p Composite after KoBo Extrusion

by Yang-Yang Wang, Chen Jia, Morteza Tayebi and Bejan Hamawandi

Materials 2022, 15(18), 6428; https://0-doi-org.brum.beds.ac.uk/10.3390/ma15186428 - 16 Sep 2022

Cited by 9 | Viewed by 1355

Abstract

In the current study, the creep properties of magnesium alloy reinforced with SiC particles were investigated. For this purpose, ZK60/SiCp composite was produced by the stir casting method following the KoBo extrusion and precipitation hardening processes. The creep tests were performed at 150 °C under 10–110 MPa. The results showed that the stress exponent (n) and the average true activation energy (Q) was changed at high stresses, was found with increasing stress, the creep mechanism changing from grain boundary sliding to dislocation climb. The results of microstructure characterization after the creep test showed that at low stresses, the dynamic recrystallization resulting from twinning induced the GBS mechanism. However, at high stresses, with increasing diffusion rates, conditions are provided for dynamic precipitation and the dislocation climb of the dominant creep mechanism. Examination of the fracture surfaces and the surrounding areas showed that the cavity nucleation in the ternary boundary and surrounding precipitation was the main cause of damage. The evaluation of the samples texture after creep showed that the unreinforced alloy showed a moderately strong fiber texture along the angle of ϕ₁ = 0–90°, which was tilted about Φ = 10°. A new strong texture component was observed at (90°, 5°, 0°) for the composite sample, which crept due to minor splitting of the basal pole by ~5° toward RD. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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12 pages, 2985 KiB

Open AccessArticle

Microstructure and Properties of a Graphene Reinforced Cu–Cr–Mg Composite

by Ruiyu Lu, Bin Liu, Huichao Cheng, Shenghan Gao, Tiejun Li, Jia Li and Qihong Fang

Materials 2022, 15(17), 6166; https://0-doi-org.brum.beds.ac.uk/10.3390/ma15176166 - 05 Sep 2022

Cited by 2 | Viewed by 1381

Abstract

To improve the graphene/copper interfacial bonding and the strength of the copper matrix, Cu–Cr–Mg alloy powder and graphene nanosheets (GNPs) have been used as raw materials in the preparation of a layered graphene/Cu–Cr–Mg composite through high-energy ball-milling and fast hot-pressing sintering. The microstructure of the composite after sintering, as well as the effect of graphene on the mechanical properties and conductivity of the composite, are also studied. The results show that the tensile strength of the composite material reached a value of 349 MPa, which is 46% higher than that of the copper matrix, and the reinforcement efficiency of graphene is as large as 136. Furthermore, the electrical conductivity of the composite material was 81.6% IACS, which is only 0.90% IACS lower than that of the copper matrix. The Cr and Mg elements are found to diffuse to the interface of the graphene/copper composite during sintering, and finely dispersed chromium carbide particles are found to significantly improve the interfacial bonding strength of the composite. Thus, graphene could effectively improve the mechanical properties of the composite while maintaining a high electrical conductivity. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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19 pages, 5946 KiB

Open AccessArticle

TEM Study of the Microstructure of an Alumina/Al Composite Prepared by Gas-Pressure Infiltration

by Krzysztof Matus, Grzegorz Matula, Mirosława Pawlyta, Jagoda Krzysteczko-Witek and Błażej Tomiczek

Materials 2022, 15(17), 6112; https://0-doi-org.brum.beds.ac.uk/10.3390/ma15176112 - 02 Sep 2022

Cited by 2 | Viewed by 1373

Abstract

Ceramic injection moulding and gas-pressure infiltration were employed for the manufacturing of alumina/AlSi₁₀Mg composites. Porous ceramic preforms were prepared by mixing alumina powder with a multi-binder system and injection moulding the powder polymer slurry. Then, the organic part was removed through a combination of solvent and thermal debinding, and, finally, the materials were sintered at different temperatures. Degrading the binder enabled open canals to form. The sintering process created a porous ceramic material consisting of alumina without any residual carbon content. During infiltration, the liquid metal filled the empty spaces (pores) effectively and formed a three-dimensional network of metal in the ceramic. The microstructure and properties of the manufactured materials were examined using high-resolution transmission electron microscopy, porosimetry, and bending strength testing. Microscopy observations showed that the fabricated composite materials are characterised by a percolation type of microstructure and a lack of unfilled pores. The research confirmed the diversified nature of the connection at the particle–matrix interface. It was observed that the interphase boundary was characterised by the lack of a transition zone between the components or a continuous transition zone, with the thickness not exceeding 30 nm. Thanks to their increased mechanical properties and low density, the obtained composites could be used in the automotive industry as a material for small piston rings and rods, connecting rods, or even gears. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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16 pages, 4510 KiB

Open AccessArticle

Microstructure and Mechanical Properties of AZ91 Rein-Forced with High Volume Fraction of Oriented Short Carbon Fibers

by Sabbah Ataya, Mohamed M. El-Sayed Seleman, Fahamsyah H. Latief, Mohamed M. Z. Ahmed, Khalil Hajlaoui, Yousef G. Y. Elshaghoul and Mohamed I. A. Habba

Materials 2022, 15(14), 4818; https://0-doi-org.brum.beds.ac.uk/10.3390/ma15144818 - 10 Jul 2022

Cited by 4 | Viewed by 1385

Abstract

In this study, AZ91/23 vol.% short carbon fiber composite was produced by a squeeze casting technique using a cylindrical pre-form of treated carbon fibers, in which the fibers are randomly oriented in the horizontal plane. Cylindrical specimens (height = 9 mm and diameter = 6 mm) were machined from the as-cast AZ91 matrix and its composite. The full behavior of the produced composite was studied through the test specimens machined in two directions, namely parallel to the reinforced plane (in the radial direction of the cast cylinder) and normal to the reinforced plane (in the axial direction of the cast composite). The microstructures of the produced composite specimens were investigated using SEM equipped with EDS analysis. Density, hardness, compressive, and wear behavior were also investigated. For comparison, the AZ91 matrix was evaluated as a reference. The microstructure of the produced AZ91 matrix alloy and its composite revealed dense materials without casting defects. Both composite specimens show improvement in hardness, compressive strength, and wear properties over the AZ91 matrix. The compressive and wear properties are more fiber orientation-dependent than the hardness results. The parallel composite specimen depicts the highest compressive properties in terms of yield compressive strength (311 MPa) and ultimate compressive strength (419 MPa), compared to that shown by the AZ91 matrix and the normal composite specimen. This improvement in compressive strength was at the expense of ductility. The parallel composite specimen shows the lowest ductility (R = 3.8%), compared to that given by the normal composite specimen (R = 7.1) and the AZ91 matrix alloy (R = 13.6). The wear testing results showed that at the highest wear load of 5 N, the material weight loss of the parallel composite specimen decreases by 44% and 64% compared to the AZ91 matrix and the normal composite specimen, respectively. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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23 pages, 23950 KiB

Open AccessArticle

The Influence of Tool Pin Geometry and Speed on the Mechanical Properties of the Bobbin Tool Friction Stir Processed AA1050

by Mohamed M. Z. Ahmed, Mohamed M. El-Sayed Seleman, Rana G. Eid, Ibrahim Albaijan and Kamel Touileb

Materials 2022, 15(13), 4684; https://0-doi-org.brum.beds.ac.uk/10.3390/ma15134684 - 04 Jul 2022

Cited by 11 | Viewed by 1445

Abstract

AA1050 plates of 8 mm thickness were processed via bobbin-tool friction stir processing technique at a constant rotation speed of 600 rpm and different travel speeds ranging from 50 to 300 mm/min using three-pin geometries of triangle, square, and cylindrical. The temperatures of the processed zone, the advancing side, and the retreating side were measured; the machine torque during processing was also recorded. The processed materials were evaluated in terms of surface roughness, macrostructure, tensile properties, and hardness measurements. The fracture surfaces of the tensile fractured specimens were investigated using SEM. The results indicated that the pin geometry and processing speed significantly affect the generated heat input and the morphology of the processed zone. The peak temperature in the center of the processed zone decreases with increasing the travel speed from 50 to 300 mm/min at all applied pin geometries. The maximum temperature of ~400 °C was reached using the cylindrical pin geometry. The machine torque increases with increasing the travel speed at all applied pin geometries, and the highest torque value of 73 N.m is recorded using the square pin geometry at 300 mm/min travel speed. The top surface roughness of the processed area using the cylindrical pin is lower than that given by the other pin geometries. Under all applied conditions, the hardness of the processed area increases with increasing travel speed, and the cylindrical pin shows a higher hardness than the other pin geometries with 19% enhancement over the BM. The AA1050 processed using a cylindrical pin at 200 mm/min travel speed and a rotation speed of 600 rpm produces a sound processing zone with the highest ultimate tensile strength of 79 MPa. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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22 pages, 9601 KiB

Open AccessArticle

The Additive Manufacturing of Aluminum Matrix Nano Al₂O₃ Composites Produced via Friction Stir Deposition Using Different Initial Material Conditions

by Mohamed M. El-Sayed Seleman, Sabbah Ataya, Mohamed M. Z. Ahmed, Ahmed M. M. Hassan, Fahamsyah H. Latief, Khalil Hajlaoui, Ahmed E. El-Nikhaily and Mohamed I. A. Habba

Materials 2022, 15(8), 2926; https://0-doi-org.brum.beds.ac.uk/10.3390/ma15082926 - 17 Apr 2022

Cited by 21 | Viewed by 2339

Abstract

The current work investigates the viability of utilizing a friction stir deposition (FSD) technique to fabricate continuous multilayer high-performance, metal-based nanoceramic composites. For this purpose, AA2011/nano Al₂O₃ composites were successfully produced using AA2011 as a matrix in two temper conditions (i.e., AA2011-T6 and AA2011-O). The deposition of matrices without nano Al₂O₃ addition was also friction stir deposited for comparison purposes. The deposition process parameters were an 800 rpm rod rotation speed and a 5 mm/min feed rate. Relative density and mechanical properties (i.e., hardness, compressive strength, and wear resistance) were evaluated on the base materials, deposited matrices, and produced composites. The microstructural features of the base materials and the friction stir deposited materials were investigated using an optical microscope (OM) and a scanning electron microscope (SEM) equipped with an EDS analysis system. The worn surface was also examined using SEM. The suggested technique with the applied parameters succeeded in producing defect-free deposited continuous multilayer AA2011-T6/nano Al₂O₃ and AA2011-O/nano Al₂O₃ composites, revealing well-bonded layers, grain refined microstructures, and homogeneously distributed Al₂O₃ particles. The deposited composites showed higher hardness, compressive strengths, and wear resistance than the deposited AA2011 matrices at the two temper conditions. Using the AA2011-T6 temper condition as a matrix, the produced composite showed the highest wear resistance among all the deposited and base materials. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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18 pages, 12093 KiB

Open AccessArticle

Microstructure and Mechanical Properties of Friction Stir Welded 2205 Duplex Stainless Steel Butt Joints

by Mohamed M. Z. Ahmed, Khalil Hajlaoui, Mohamed M. El-Sayed Seleman, Mahmoud F. Elkady, Sabbah Ataya, Fahamsyah H. Latief and Mohamed I. A. Habba

Materials 2021, 14(21), 6640; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14216640 - 04 Nov 2021

Cited by 11 | Viewed by 1778

Abstract

Friction stir welding (FSW) as a solid-state process is an excellent candidate for high softening temperature materials welding; however, extending the tool life is required to make the process cost-effective. This work investigates the use of a high pin to shoulder ratio (65%) tungsten carbide (WC) tool for friction stir welding of 5 mm thick 2205 DSS to extend the tool life of this low-cost tool material. In addition, the effect of FSW parameters in terms of rotational rates, travel speeds, and downward forces on the microstructural features and mechanical properties of the welded joints were investigated. Characterization in terms of visual inspection, macro and microstructures, hardness, and tensile testing was conducted. The obtained results indicated that the combined rotational rate, travel speed, and downward force parameters govern the production of defect-free joints. The 2205 DSS friction stir welds show an enhancement in hardness compared to the base material. The stir zone showed a significantly refined grain structure of ferrite and austenite with the reduction in the average grain size from 8.8 µm and 13.3 µm for the base material to 2.71 µm and 2.24 µm, respectively. Moreover, this joint showed higher yield strength and ultimate tensile strength compared to the DSS as-received material. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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14 pages, 6835 KiB

Open AccessArticle

Analysis of the Quality of Sulfomolybdenum Coatings Obtained by Electrospark Alloying Methods

by Oksana P. Gaponova, Bogdan Antoszewski, Viacheslav B. Tarelnyk, Piotr Kurp, Oleksandr M. Myslyvchenko and Nataliia V. Tarelnyk

Materials 2021, 14(21), 6332; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14216332 - 23 Oct 2021

Cited by 5 | Viewed by 1209

Abstract

The authors of this paper have attempted to improve the quality of surface layers applied to steel elements of machine parts constituting friction couples. The main goal of the research was to investigate an electrospark alloying method process for obtaining abrasion-resistant tribological coatings containing molybdenum disulfide on a steel surface. A substance in the form of sulfur ointment with a sulfur content of 33.3% was applied on the surfaces of C22 and C40 steel specimens. In order to determine the influence of the energy parameters of ESA equipment on the quality parameters of coatings, the ESA process was carried out using a molybdenum electrode with discharge energies Wp = 0.13; Wp = 0.55; Wp = 3.4 J. The following tests were carried out on specimens with such coatings: metallographic analysis, microhardness tests, surface roughness, and local X-ray diffraction microanalysis. The experiments revealed that sulfomolybdenum coatings consist of four zones with different mechanical properties. Depending on the discharge energy and the substrate material, the hardness of these zones varies from approx. 1100 to over 10,000 MPa. Differences in the distribution of, among others, sulfur and molybdenum in the obtained coatings, as well as differences in the microstructure of the observed coatings, were observed. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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14 pages, 12255 KiB

Open AccessArticle

The Applicability of Die Cast A356 Alloy to Additive Friction Stir Deposition at Various Feeding Speeds

by Bandar Alzahrani, Mohamed M. El-Sayed Seleman, Mohamed M. Z. Ahmed, Ebtessam Elfishawy, Adham M. Z. Ahmed, Kamel Touileb, Nabil Jouini and Mohamed I. A. Habba

Materials 2021, 14(20), 6018; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14206018 - 13 Oct 2021

Cited by 20 | Viewed by 1924

Abstract

In the current investigation, additive friction stir-deposition (AFS-D) of as-cast hypoeutectic A356 Al alloy was conducted. The effect of feeding speeds of 3, 4, and 5 mm/min at a constant rotational speed of 1200 rpm on the macrostructure, microstructure, and hardness of the additive manufacturing parts (AMPs) was investigated. Various techniques (OM, SEM, and XRD) were used to evaluate grain microstructure, presence phases, and intermetallics for the as-cast material and the AMPs. The results showed that the friction stir deposition technique successfully produced sound additive manufactured parts at all the applied feeding speeds. The friction stir deposition process significantly improved the microstructure of the as-cast alloy by eliminating porosity and refining the dendritic α-Al grains, eutectic Si phase, and the primary Si plates in addition to intermetallic fragmentation. The mean values of the grain size of the produced AMPs at the feeding speeds of 3, 4, and 5 mm/min were 0.62 ± 0.1, 1.54 ± 0.2, and 2.40 ± 0.15 µm, respectively, compared to the grain size value of 30.85 ± 2 for the as-cast alloy. The AMPs exhibited higher hardness values than the as-cast A356 alloy. The as-cast A356 alloy showed highly scattered hardness values between 55 and 75.8 VHN. The AMP fabricated at a 3 mm/min feeding speed exhibited the maximum hardness values between 88 and 98.1 VHN. Full article

(This article belongs to the Special Issue Advanced Manufacturing of Metals and Composites: Effect of Processes on Microstructure and Mechanical Properties)

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