Papers by Keyword: Vickers Microhardness

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Authors: H. Bedboudi, A. Bourbia, M. Draissia, S. Boulkhessaim, M.Y. Debili
Abstract: Rapidly solidified Al-Zn alloys with Zn contents ranging up to 50 wt.% were made under vacuum, by high-frequency (HF) induction melting, from compacted mixture targets of Al and Zn of fine (99.99 % purity) elemental powders. The microstructural characteristics and strengthening mechanisms were investigated. The crystallographic microstructures were characterized by means of X-ray diffraction (XRD) analyses and optical microscopy observations as well as Vickers microhardness testing. Detailed overviews of alloying solubility of zinc in aluminium were given. Extensive solid solutions of CFC Al were found in the (HF) Al-Zn alloys, and a higher Vickers microhardnesses compared to that of pure (HF) aluminium.
Authors: Yoshiyasu Kawasaki, Koji Neishi, Yuichi Miyahara, Katsuaki Nakamura, Kenji Kaneko, Michihiko Nakagaki, Z. Horita
Authors: Ehsan. A.H. Gomaa, M. Mohsen, A.S. Taha, M.M. Mostafa
Abstract: The variations during isochronal annealing of cold-rolled commercial pure Al (1050) and Al-Mn (3004) has been investigated between room temperature (RT) and 823 K. The annealing stages have been identified as recovery, partial recrystallization, complete recrystallization and grain growth using positron annihilation lifetime (PAL) spectroscopy, Doppler broadening of annihilation radiation (DBAR) spectroscopy and Vickers microhardness (Hv) measurements. The retardation of complete recovery in Al-Mn alloys is due to the presence of vacancy-Mn complexes. A positive correlation has been found between positron annihilation parameters (τav & Snor) and mechanical properties (Hv) for the two alloys under investigation.
Authors: Y.J. Zheng, Tohru Yamasaki, Mititaka Terasawa, Tohru Mitamura, Takeshi Fukami
Authors: Mohamed Osman, Dian Tao Zhang, Yun Xiang Tong, Yu Feng Zheng, Li Li
Abstract: Ti-50.8%Ni shape memory alloy was subjected to four passes equal channel angular pressing (ECAP) with angle 120◦ via route Bc at 450°C. The deformation homogeneity was analyzed on planes across the thickness of the deformed sample by Deform-3D software. Two methods were used from the simulation model to quantify deformation homogeneity , including strain standard deviation (SSD) and inhomogeneity index (Ci). In addition, The deformation heterogeneity of ECAP was analyzed experimentally from microhardness inhomogeneity index ( HII) based on Vickers microhardness test results.In the present work, Ci and SSD had been testified to detect which one could give better results experimentally. It was demonstrated that the simulation results of SSD measurements were in good agreement with experimental results .
Authors: Min Jin, Jia Yue Xu, Yao Qing Chu, Yong Zheng Fang, Hui Shen, Guo Jian Jiang, Zhan Yong Wang
Abstract: In this work, the mechanical properties, such as Vickers microhardness Hv, fracture toughness Kc, yield strength σv and brittleness index Bi, of <0001> oriented 6H-SiC crystal are systematically evaluated using a microindentation technique under 0.1-2 kg applied load. It is found the Hv is decreased as the applied load is increased which is mainly attributed to the effect of indenter penetration. The Hv value can be effectively presumed by Kicks law and the Meyers index n is determined to be 1.73. However, the Kc value is measured nearly a constant (~0.148 MPa.m1/2) which reveals the toughness of 6H-SiC(0001) crystal is much weaker than those of Si(100) and GaAs(100) crystals. The variation of σv to the load is similar to that of Hv. The brittleness index Bi also exhibits deceasing tendency as the applied load is added.
Authors: Afshin Mohammad Hosseini, S.H. Masood, Darren Fraser, Mahnaz Jahedi
Abstract: Electron beam melting (EBM) is a direct metal additive manufacturing technique which has been recently utilized for fabrication of biomedical implants. This paper represents an investigation into the mechanical properties of both as-built and hot isostatic pressing (HIP) processed samples manufactured in EBM process. The titanium alloy, Ti6Al4V was used, which is one of the most common materials for biomedical implants due to its high strength to weight ratio, corrosion resistance, and its biocompatibility features. Tensile properties, surface roughness, and Vickers microhardness have been investigated.
Authors: J. Nemati, Shamsuddin Sulaiman, B.T. Hang Tuah Baharudin, M.A. Azmah Hanim, G.H. Majzoobi
Abstract: In this study, annealed AL-6063 alloy was processed by the Equal Channel Angular Extrusion (ECAE) up to 6 passes at a temperature of 200°c following route A with a constant ram speed of 30 mm/min through a die angle of 90° between the die channels. The influence of ECAE processing on the evolution of microhardness in the material was studied using Vickers microhardness testing. The detailed analysis was carried out on the samples of as-received, one, two, three, four, five, and six pass conditions. The grain diameter reduced from 45μm to 2.8 μm after 6 passes of ECAE. The results indicated around 90% increase in Microhardness after 5 passes. Hardness of the inner surface where the billet was under compression was slightly higher than that of the mid-surface.
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