The microstructure of the 18R-type long period stacking ordered （LPSO） phase in Mg 97 Y 2 Zn 1 alloy was investigated by the first principles calculation. The arrangement rule of Zn and Y atoms in the LPSO structure...The microstructure of the 18R-type long period stacking ordered （LPSO） phase in Mg 97 Y 2 Zn 1 alloy was investigated by the first principles calculation. The arrangement rule of Zn and Y atoms in the LPSO structure is determined theoretically. The calculation results reveal that the additive atoms are firstly located in the fault layers at the two ends of the 18R-type LPSO structure, and then extend to fault layers in the interior, which is in good agreement with the experimental observations. This feature also implies the microstructural relationship between 18R and other LPSO structures. The cohesive energy and the formation heat indicate the dependence of the stability of 18R LPSO structure on contents of Y and Zn atoms. The calculated electronic structures reveal the underlying mechanism of microstructure and the stability of 18R LPSO structure.展开更多
通过光学显微镜、扫描电镜分析了铸态及固溶处理态Mg97Zn1Y2合金的显微组织,并利用EDS,XRD进行了物相分析。研究发现,固溶处理后,Mg97Zn1Y2合金中的长周期结构相（long period stacking ordered,LPSO）发生长大,由离散分布变为连续分布...通过光学显微镜、扫描电镜分析了铸态及固溶处理态Mg97Zn1Y2合金的显微组织,并利用EDS,XRD进行了物相分析。研究发现,固溶处理后,Mg97Zn1Y2合金中的长周期结构相（long period stacking ordered,LPSO）发生长大,由离散分布变为连续分布。阻尼测试结果显示,固溶处理后Mg97Zn1Y2合金阻尼性能下降。通过对铸态及固溶处理态Mg97Zn1Y2合金进行阻尼-温度谱分析,发现存在2个内耗峰：P1内耗峰位置在150-250℃附近,峰宽很宽,是由位错机制引起的内耗峰;P2内耗峰位置在350-500℃附近,初步认为是晶界内耗峰。展开更多
基金Projects(50861002,51071053)supported by the National Natural Science Foundation of ChinaProject(0991051)supported by NaturalScience Foundation of Guangxi Province,China+1 种基金Project(KF0803)supported by Open Project of Key Laboratory of Materials Design and Preparation Technology of Hunan Province,ChinaProject(X071117)supported by Scientific Research Foundation of Guangxi University,China
文摘The microstructure of the 18R-type long period stacking ordered （LPSO） phase in Mg 97 Y 2 Zn 1 alloy was investigated by the first principles calculation. The arrangement rule of Zn and Y atoms in the LPSO structure is determined theoretically. The calculation results reveal that the additive atoms are firstly located in the fault layers at the two ends of the 18R-type LPSO structure, and then extend to fault layers in the interior, which is in good agreement with the experimental observations. This feature also implies the microstructural relationship between 18R and other LPSO structures. The cohesive energy and the formation heat indicate the dependence of the stability of 18R LPSO structure on contents of Y and Zn atoms. The calculated electronic structures reveal the underlying mechanism of microstructure and the stability of 18R LPSO structure.
文摘通过光学显微镜、扫描电镜分析了铸态及固溶处理态Mg97Zn1Y2合金的显微组织,并利用EDS,XRD进行了物相分析。研究发现,固溶处理后,Mg97Zn1Y2合金中的长周期结构相（long period stacking ordered,LPSO）发生长大,由离散分布变为连续分布。阻尼测试结果显示,固溶处理后Mg97Zn1Y2合金阻尼性能下降。通过对铸态及固溶处理态Mg97Zn1Y2合金进行阻尼-温度谱分析,发现存在2个内耗峰：P1内耗峰位置在150-250℃附近,峰宽很宽,是由位错机制引起的内耗峰;P2内耗峰位置在350-500℃附近,初步认为是晶界内耗峰。
