The influence of trace Y on the microstructure evolution and mechanical properties of Mg_(100−x)Y_(x)(x=0.25,_(0.75),1.5,3,4,5,at.%)alloys during solidification process was investigated via molecular dynamics(MD)simul...The influence of trace Y on the microstructure evolution and mechanical properties of Mg_(100−x)Y_(x)(x=0.25,_(0.75),1.5,3,4,5,at.%)alloys during solidification process was investigated via molecular dynamics(MD)simulations.The results show that the Mg_(100−x)Y_(x) alloys are mainly characterized by a face-centered cubic(FCC)crystal structure;this is different from pure metal Mg,which exhibits a hexagonal close packed(HCP)structure at room temperature.Among these alloys,Mg_(99.25)Y_(0.75) has a larger proportion of FCC cluster structures,with the highest fraction reaching 56.65%.As the content of the Y increases up to 5 at.%(Mg95Y5 alloy),the amount of amorphous structures increases.The mechanical properties of the Mg_(100−x)Y_(x) alloys are closely related to their microstructures.The Mg_(99.25)Y_(0.75) and Mg_(97)Y_(3) alloys exhibit the highest yield strengths of 1.86 and 1.90 GPa,respectively.The deformation mechanism of the Mg−Y alloys is described at the atomic level,and it is found that a difference in the FCC proportion caused by different Y contents leads to distinct deformation mechanisms.展开更多
基金the National Key Research and Development Program of China (No. 2017YFGX090043)the Program for New Century Excellent Talents in University, China (No. NCET-12-0170) for supporting this work。
文摘The influence of trace Y on the microstructure evolution and mechanical properties of Mg_(100−x)Y_(x)(x=0.25,_(0.75),1.5,3,4,5,at.%)alloys during solidification process was investigated via molecular dynamics(MD)simulations.The results show that the Mg_(100−x)Y_(x) alloys are mainly characterized by a face-centered cubic(FCC)crystal structure;this is different from pure metal Mg,which exhibits a hexagonal close packed(HCP)structure at room temperature.Among these alloys,Mg_(99.25)Y_(0.75) has a larger proportion of FCC cluster structures,with the highest fraction reaching 56.65%.As the content of the Y increases up to 5 at.%(Mg95Y5 alloy),the amount of amorphous structures increases.The mechanical properties of the Mg_(100−x)Y_(x) alloys are closely related to their microstructures.The Mg_(99.25)Y_(0.75) and Mg_(97)Y_(3) alloys exhibit the highest yield strengths of 1.86 and 1.90 GPa,respectively.The deformation mechanism of the Mg−Y alloys is described at the atomic level,and it is found that a difference in the FCC proportion caused by different Y contents leads to distinct deformation mechanisms.
