近期,我系张德平副研究员,李伯琼教授和赵亚丽教授等的”Creep behavior and microstructure evolution of heat-resistant Mg-Sm-Yb-Zn-Zr alloy”在《Materials Science and Engineering A》上发表。
论文简介如下:
In this work, we investigated creep behavior and microstructure evolution of cast Mg-4Sm-2Yb-0.6Zn-0.4Zralloy. The alloy exhibited temperature-dependent stress exponents (n=4.7, 5.8, and 7.2 at 200, 225, and250◦C, respectively) and high creep activation energies ranging from 112 kJ/mol to 504 kJ/mol. Given theconsiderable influence of the temperature on the minimum creep rate, a normalized stress exponent of ~4 wasderived, implying that dislocation creep was operative. Abnormally high creep activation energies could beassociated with the thermally stable intermetallic at grain boundaries and high density of precipitates within theα-Mg matrix. An analysis of the dislocation substructure confirmed that the main creep mechanisms were bothcross-slip and climb of<a>dislocations. During creep, the precipitation of both prismaticβphases and basalγ’’phases in theα-Mg matrix formed closed volumes, effectively arresting dislocations and contributing to thehigher creep resistance than the majority of creep-resistant Mg alloys, such as traditional Mg-RE-based cast alloysand die-cast Mg benchmark alloys.
本文下载地址:https://doi.org/10.1016/j.msea.2022.143358