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M Y Zheng - One of the best experts on this subject based on the ideXlab platform.
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microstructure and room temperature tensile properties of 1 μm sicp az31b magnesium matrix composite
Journal of Magnesium and Alloys, 2015Co-Authors: M J Shen, M Y Zheng, Xianjie Wang, M F Zhang, B H Zhang, Kaining WuAbstract:Abstract In the present study, AZ31B magnesium matrix composites reinforced with two volume fractions (3 and 5 vol.%) of micron-SiC particles(1 μm) were fabricated by semisolid stirring assisted ultrasonic vibRation method. The as-cast ingots were extruded at 350 °C with the Extrusion Ratio of 15:1 at a constant ram speed of 15 mm/s. The microstructure of the composites was investigated by optical microscopy, scanning electron microscope and transmission electron microscope. Microstructure characterization of the composites showed relative uniform reinforcement distribution and significant grain refinement. The presence of 1 μm-SiC particles assisted in improving the elastic modulus and tensile strength. The ultimate tensile strength and yield strength of the 5 vol.% SiCp/AZ31B composites were simultaneously improved.
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effect of Extrusion Ratio on microstructure texture and mechanical properties of indirectly extruded mg zn ca alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013Co-Authors: L Tong, Shigeharu Kamado, M Y Zheng, L R Cheng, Hongjie ZhangAbstract:Indirect Extrusion of as-cast Mg-5.25 Zn-0.6 Ca (wt%) alloy was performed at 300 degrees C with different Extrusion Ratios (ER, 20:1 and 10:1), and the microstructure, texture and tensile properties of the as-extruded alloys were investigated in the current study. With the increase of ER, the volume fraction of DRXed grains was remarkably increased, but the average DRXed grains size was almost unchanged. The basal texture weakening phenomenon occurred in the as-extruded alloy with higher ER, which resulted from the higher volume fraction of the DRXed grain. Intensive basal fiber texture was observed in the unDRXed grains, but the basal planes of the DRXed grains were inclined to ED from 0 degrees to 35 degrees. The ER had only little effect on the tensile properties of the as-extruded alloys; due to the similar strengthening effect from the unDRXed and DRXed grains, a competitive mechanism exists between the fine grain strengthening and texture weakening effect. (C) 2013 Elsevier B.V. All rights reserved.
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effect of hot Extrusion on microstructures and mechanical properties of sic nanoparticles reinforced magnesium matrix composite
Journal of Alloys and Compounds, 2012Co-Authors: Xiaojun Wang, K Wu, L Xu, X S Hu, M Y ZhengAbstract:Abstract Particulate reinforced magnesium matrix nanocomposite prepared with semisolid stirring assisted ultrasonic vibRation was subjected to Extrusion at 350 °C with an Extrusion Ratio of 12:1. Extrusion of the SiCp/AZ91 nanocomposite induced large scale dynamic recrystallization resulting in a fine matrix microstructure. There were two kinds of zones in the extruded nanocomposite: SiC nanoparticle bands parallel to the Extrusion direction and refined-grain zones between the SiC nanoparticle bands. In the SiC nanoparticle bands, there were SiC nanoparticles along the boundaries of refined grains. The distribution of SiC nanoparticles was uniform although some agglomerates of SiC nanoparticles still existed in the SiC nanoparticle bands. The ultimate tensile strength, yield strength and elongation to fracture of the SiCp/AZ91 nanocomposite were simultaneously improved by Extrusion. Results from the extruded SiCp/AZ91 nanocomposite tensile testing at different temperatures (75, 125, 175 and 225 °C) revealed an increase of the tensile strength and ductility values compared with the unreinforced and extruded AZ91 alloy.
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effect of hot Extrusion on the microstructure of a particulate reinforced magnesium matrix composite
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2007Co-Authors: Xiaojun Wang, M Y Zheng, K Wu, Hongbin Zhang, Wei Huang, H Chang, D L PengAbstract:Abstract A particulate reinforced magnesium matrix composite fabricated by stir casting was extruded at 250 °C with an Extrusion Ratio of 12:1 and constant RAM speed of 15 mm/s. Extrusion of the composite causes large scale dynamic recrystallization resulting in a fine matrix microstructure. The reinforcing particles stimulate dynamic recrystallization, and dynamic recrystallization in the composite is sensitive to the particle content on a local scale. The particle distribution of the composite before and after Extrusion was studied using a window technique. It is found that the segregation of particles in the as-cast composite is largely eliminated by Extrusion and the particle distribution is significantly improved. Extrusion-induced damage to the reinforcement is observed in the extruded composites, and the particle fracture induced by Extrusion is also sensitive to the particle content on a local scale.
Shigeharu Kamado - One of the best experts on this subject based on the ideXlab platform.
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effects of Extrusion Ratio and temperature on the mechanical properties and microstructure of as extruded mg gd y nd zn zr alloys
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2019Co-Authors: Jia Meng, Ke Liu, Shigeharu KamadoAbstract:Abstract This study investigates the effects of Extrusion Ratio and temperature on the microstructure and mechanical properties of as-extruded Mg-11.5Gd-4.5Y-(1Nd/1.5Zn)-0.3Zr (wt %) alloys. After hot Extrusion the studied alloys exhibit a bimodal microstructure consisting of fine dynamic recrystallized (DRXed) grains with relatively random orientations and coarse un-DRXed grains with strong basal texture. The increase of Extrusion Ratio promotes the DRX, increases the volume fraction of Mg5RE phase, and refines the DRXed grains, whereas the increase of Extrusion temperature decreases the volume fraction of Mg5RE phase and coarsens the DRXed grains. The increase of Extrusion temperature suppresses the DRX of Mg-11.5Gd-4.5Y-0.3Zr (GW) and Mg-11.5Gd-4.5Y-1Nd-0.3Zr (GWN) alloys, but it has a limited effect on that of Mg-11.5Gd-4.5Y-1.5Zn-0.3Zr (GWZ) alloy. The increase of Extrusion Ratio improves the mechanical properties of GWZ and GWN alloys, while it deteriorates the mechanical property of GW alloy. The increase of Extrusion temperature leads to a decreased strength and increased ductility of the studied alloys. The change of mechanical properties is a result of the competition between the “strengthening effect” of DRXed grains and the “hardening effect” of un-DRXed grains in the changing bimodal microstructure. The Mg5RE phase also contributes to the alloy strengthening, but the extensive Mg5RE precipitates acting as the crack resources are detrimental to the ductility, especially for the GWN alloy. With the optimum Extrusion condition (temperature of 450 °C and Ratio of 20:1) the GWZ alloy exhibits the best mechanical performance, which is superior to that of its competitor 6000 series aluminum alloys.
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effect of Extrusion Ratio on microstructure texture and mechanical properties of indirectly extruded mg zn ca alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013Co-Authors: L Tong, Shigeharu Kamado, M Y Zheng, L R Cheng, Hongjie ZhangAbstract:Indirect Extrusion of as-cast Mg-5.25 Zn-0.6 Ca (wt%) alloy was performed at 300 degrees C with different Extrusion Ratios (ER, 20:1 and 10:1), and the microstructure, texture and tensile properties of the as-extruded alloys were investigated in the current study. With the increase of ER, the volume fraction of DRXed grains was remarkably increased, but the average DRXed grains size was almost unchanged. The basal texture weakening phenomenon occurred in the as-extruded alloy with higher ER, which resulted from the higher volume fraction of the DRXed grain. Intensive basal fiber texture was observed in the unDRXed grains, but the basal planes of the DRXed grains were inclined to ED from 0 degrees to 35 degrees. The ER had only little effect on the tensile properties of the as-extruded alloys; due to the similar strengthening effect from the unDRXed and DRXed grains, a competitive mechanism exists between the fine grain strengthening and texture weakening effect. (C) 2013 Elsevier B.V. All rights reserved.
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study of the microstructure texture and tensile properties of as extruded az91 magnesium alloy
Journal of Alloys and Compounds, 2008Co-Authors: Hanlin Ding, Wenjiang Ding, Shigeharu Kamado, Yo KojimaAbstract:Abstract The microstructure, texture and tensile properties of AZ91 magnesium alloy that was extruded at 300 and 360 °C with Extrusion Ratios of 5.5 and 22 are investigated. The occurrence of dynamic recrystallization, precipitation of second phase (Mg 17 Al 12 ) particles and the formation of basal texture during Extrusion are observed by electron back scattered diffraction patterns analyses. Along with the increase of either the Extrusion temperature or Extrusion Ratio, the tensile strength decreases and the ductility increases. The precipitation of the second phase is beneficial to the grain refinement and in turn to the promotion of the tensile strength. The fracture analysis shows that the deformation twinning plays an important role in increasing the elongation.
Xiaojun Wang - One of the best experts on this subject based on the ideXlab platform.
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effect of hot Extrusion on microstructures and mechanical properties of sic nanoparticles reinforced magnesium matrix composite
Journal of Alloys and Compounds, 2012Co-Authors: Xiaojun Wang, K Wu, L Xu, X S Hu, M Y ZhengAbstract:Abstract Particulate reinforced magnesium matrix nanocomposite prepared with semisolid stirring assisted ultrasonic vibRation was subjected to Extrusion at 350 °C with an Extrusion Ratio of 12:1. Extrusion of the SiCp/AZ91 nanocomposite induced large scale dynamic recrystallization resulting in a fine matrix microstructure. There were two kinds of zones in the extruded nanocomposite: SiC nanoparticle bands parallel to the Extrusion direction and refined-grain zones between the SiC nanoparticle bands. In the SiC nanoparticle bands, there were SiC nanoparticles along the boundaries of refined grains. The distribution of SiC nanoparticles was uniform although some agglomerates of SiC nanoparticles still existed in the SiC nanoparticle bands. The ultimate tensile strength, yield strength and elongation to fracture of the SiCp/AZ91 nanocomposite were simultaneously improved by Extrusion. Results from the extruded SiCp/AZ91 nanocomposite tensile testing at different temperatures (75, 125, 175 and 225 °C) revealed an increase of the tensile strength and ductility values compared with the unreinforced and extruded AZ91 alloy.
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effect of hot Extrusion on the microstructure of a particulate reinforced magnesium matrix composite
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2007Co-Authors: Xiaojun Wang, M Y Zheng, K Wu, Hongbin Zhang, Wei Huang, H Chang, D L PengAbstract:Abstract A particulate reinforced magnesium matrix composite fabricated by stir casting was extruded at 250 °C with an Extrusion Ratio of 12:1 and constant RAM speed of 15 mm/s. Extrusion of the composite causes large scale dynamic recrystallization resulting in a fine matrix microstructure. The reinforcing particles stimulate dynamic recrystallization, and dynamic recrystallization in the composite is sensitive to the particle content on a local scale. The particle distribution of the composite before and after Extrusion was studied using a window technique. It is found that the segregation of particles in the as-cast composite is largely eliminated by Extrusion and the particle distribution is significantly improved. Extrusion-induced damage to the reinforcement is observed in the extruded composites, and the particle fracture induced by Extrusion is also sensitive to the particle content on a local scale.
K Wu - One of the best experts on this subject based on the ideXlab platform.
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effect of hot Extrusion on microstructures and mechanical properties of sic nanoparticles reinforced magnesium matrix composite
Journal of Alloys and Compounds, 2012Co-Authors: Xiaojun Wang, K Wu, L Xu, X S Hu, M Y ZhengAbstract:Abstract Particulate reinforced magnesium matrix nanocomposite prepared with semisolid stirring assisted ultrasonic vibRation was subjected to Extrusion at 350 °C with an Extrusion Ratio of 12:1. Extrusion of the SiCp/AZ91 nanocomposite induced large scale dynamic recrystallization resulting in a fine matrix microstructure. There were two kinds of zones in the extruded nanocomposite: SiC nanoparticle bands parallel to the Extrusion direction and refined-grain zones between the SiC nanoparticle bands. In the SiC nanoparticle bands, there were SiC nanoparticles along the boundaries of refined grains. The distribution of SiC nanoparticles was uniform although some agglomerates of SiC nanoparticles still existed in the SiC nanoparticle bands. The ultimate tensile strength, yield strength and elongation to fracture of the SiCp/AZ91 nanocomposite were simultaneously improved by Extrusion. Results from the extruded SiCp/AZ91 nanocomposite tensile testing at different temperatures (75, 125, 175 and 225 °C) revealed an increase of the tensile strength and ductility values compared with the unreinforced and extruded AZ91 alloy.
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effect of hot Extrusion on the microstructure of a particulate reinforced magnesium matrix composite
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2007Co-Authors: Xiaojun Wang, M Y Zheng, K Wu, Hongbin Zhang, Wei Huang, H Chang, D L PengAbstract:Abstract A particulate reinforced magnesium matrix composite fabricated by stir casting was extruded at 250 °C with an Extrusion Ratio of 12:1 and constant RAM speed of 15 mm/s. Extrusion of the composite causes large scale dynamic recrystallization resulting in a fine matrix microstructure. The reinforcing particles stimulate dynamic recrystallization, and dynamic recrystallization in the composite is sensitive to the particle content on a local scale. The particle distribution of the composite before and after Extrusion was studied using a window technique. It is found that the segregation of particles in the as-cast composite is largely eliminated by Extrusion and the particle distribution is significantly improved. Extrusion-induced damage to the reinforcement is observed in the extruded composites, and the particle fracture induced by Extrusion is also sensitive to the particle content on a local scale.
Katsuyoshi Kondoh - One of the best experts on this subject based on the ideXlab platform.
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powder metallurgy ti tic metal matrix composites prepared by in situ reactive processing of ti vgcfs system
Carbon, 2013Co-Authors: Shufeng Li, Hisashi Imai, Katsuyoshi KondohAbstract:Abstract Titanium metal matrix composites (TMCs) were fabricated via powder metallurgy (P/M) and hot Extrusion. Planetary ball milling (PBM) was employed to disperse 0.4–1.0 wt% multiwall carbon nanotubes (VGCFs) with pure Ti powder. The fragmented VGCFs were found dispersing homogenously on the flaked Ti particles surface after PBMed for 24 h. The powder mixture was consolidated at 1073 K by the spark plasma sintering (SPS) process. Hot Extrusion was performed at 1273 K with an Extrusion Ratio of 37:1. The microstructures and mechanical properties of the extruded Ti-VGCFs composites were investigated to evaluate the reactive processing of Ti-VGCFs system. The extruded Ti-VGCFs composites, with a 1.0 wt% VGCFs additive dispersed by PBM, exhibited an excellent tensile strength of 1182 MPa in 0.2% YS and 1179 MPa in UTS, which demonstrated a 143.6% and 80.7% increase compared to these of the extruded pure Ti, respectively. The strengthening mechanism was investigated and elucidated that the mechanical strength was attributed to the grain refinement and dispersion strengthening of the homogenously dispersed, in situ formed TiC particulates, as well as a solid solution strengthening of the carbon, oxygen and nitrogen elements in the Ti matrix.
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powder metallurgy titanium metal matrix composites reinforced with carbon nanotubes and graphite
Composites Part A-applied Science and Manufacturing, 2013Co-Authors: Shufeng Li, Hisashi Imai, Takanori Mimoto, Katsuyoshi KondohAbstract:Abstract Carbon nanotubes (VGCF) and graphite (Gr) reinforced Ti metal matrix composites (TiMMCs) were prepared via powder metallurgy. 0–0.4 wt% VGCF/Gr and Ti mixture powders were prepared by rocking mill. The as-premixed powders were consolidated at 1073 K using spark plasma sintering (SPS). Hot Extrusion was performed at 1273 K with an Extrusion Ratio of 37:1. Microstructures and mechanical properties of the as-extruded Ti composites were investigated to evaluate strengthening effects of VGCF/Gr on Ti matrix. Mechanical strength of Ti–VGCF/Gr composites was augmented when VGCF/Gr contents were increased from 0.1 to 0.4 wt%. Yield strength (YS) and ultimate tensile strength (UTS) of Ti-0.4 wt% VGCF composites were increased 40.4% and 11.4% as compared to pure Ti, while those values were 30.5% and 2.1% for Ti–0.4 wt% Gr. The strengthening mechanism including grain refinement, carbon solid solution strengthening and TiC/carbon dispersion strengthening was discussed in detail.
