Fine-grained Mg-6Zn-4Y alloy was prepared by an ingot metallurgy process with hot extrusion at 300 ℃.The microstructure was studied by XRD,OM,SEM and TEM,and the tensile properties were tested at room temperature.The...Fine-grained Mg-6Zn-4Y alloy was prepared by an ingot metallurgy process with hot extrusion at 300 ℃.The microstructure was studied by XRD,OM,SEM and TEM,and the tensile properties were tested at room temperature.The results show that the alloy is composed of α-Mg and W-phase.The microstructure of the as-extruded alloy has a bimodal grain size distribution.The fine grains with the mean size of 1.2 μm are formed by dynamic recrystallization.The coarse grains（about 23% in area fraction） are unrecrystallized regions which are elongated along extrusion direction.The engineering stress—strain curve shows a pronounced yield point.The ultimate tensile strength,yield strength,and elongation are（371±10） MPa,（350±5） MPa and（7±2）%,respectively.The high strengths are attributed to the fine-grained matrix structure enhanced by W-phase particles,nano-scaled precipitates,and strong basal plane texture.展开更多
基金Project (50271054) supported by the National Natural Science Foundation of ChinaProject (20070700003) supported by the Doctorate Programs Foundation of Ministry of Education of China+1 种基金Project (102102210031) supported by the Science and Technologies Foundation of Henan Province, ChinaProject (2010A430008) supported by the Natural Science Foundation of Henan Educational Committee of China
文摘Fine-grained Mg-6Zn-4Y alloy was prepared by an ingot metallurgy process with hot extrusion at 300 ℃.The microstructure was studied by XRD,OM,SEM and TEM,and the tensile properties were tested at room temperature.The results show that the alloy is composed of α-Mg and W-phase.The microstructure of the as-extruded alloy has a bimodal grain size distribution.The fine grains with the mean size of 1.2 μm are formed by dynamic recrystallization.The coarse grains（about 23% in area fraction） are unrecrystallized regions which are elongated along extrusion direction.The engineering stress—strain curve shows a pronounced yield point.The ultimate tensile strength,yield strength,and elongation are（371±10） MPa,（350±5） MPa and（7±2）%,respectively.The high strengths are attributed to the fine-grained matrix structure enhanced by W-phase particles,nano-scaled precipitates,and strong basal plane texture.
