Effect of Sm on the microstructure, mechanical properties and creep behavior of Mg–0.5Zn–0.4Zr based alloys
Effect of Sm on the microstructure, mechanical properties and creep behavior of Mg–0.5Zn–0.4Zr based alloys
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DOI：
10.1016/j.msea.2009.10.067
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发表时间：
2010-03
期刊：
影响因子：
6.4
通讯作者：
Jiang Zheng;Qudong Wang;Zhe Jin;T. Peng
中科院分区：
文献类型：
--
作者：
Jiang Zheng;Qudong Wang;Zhe Jin;T. Peng
本研究的目的是研究添加剂（0.4，0.5，1.5，3和5 wt.%）的影响。Sm对Mg-0.5Zn-0.4Zr合金显微组织、力学性能的影响。实验结果表明，少量Sm的加入可使晶界析出Mg 41 Sm 5共晶相，细化铸态晶粒。当Sm含量增加到3%时，在靠近晶界的区域形成大量细小的板状析出物，有效地阻碍位错滑移，对提高拉伸和蠕变性能起重要作用。Mg-（0.4-0.7）Sm-0.5Zn-0.4Zr合金的断裂模式为穿晶断裂，Mg-1.5Sm-0.5Zn-0.4Zr合金的断裂模式为穿晶断裂和沿晶断裂，Mg-（3-5）Sm-0.5Zn-0.4Zr合金的断裂模式为沿晶断裂。研究了Mg-3Sm-0.5Zn-0.4Zr合金在200-225°C温度范围和60- 100 MPa应力范围内的稳态蠕变速率与应力和温度的关系，提出了不同条件下的蠕变机制。
The present study aims at investigating the effect of additions (0.4, 0.5, 1.5, 3, and 5wt.%) of samarium on the microstructure, mechanical properties of Mg–0.5Zn–0.4Zr alloy. Experimental results show that a small amount of samarium addition can bring about precipitation of eutectic Mg41Sm5phases at the grain boundaries and refine the as-cast grains. When samarium content increasing to 3%, a great number of fine plate-shaped precipitates form in the regions close to grain boundaries, and could effectively hinder dislocation slip and play important roles in improving tensile and creep properties. Furthermore, the transition of fracture mode as a function of samarium content can be generally described as follows: trans-granular fracture in Mg–(0.4–0.7)Sm–0.5Zn–0.4Zr alloys, both trans-granular and inter-granular fracture in Mg–1.5Sm–0.5Zn–0.4Zr alloys, and inter-granular fracture in Mg–(3–5)Sm–0.5Zn–0.4Zr alloys. Stress and temperature dependence of the steady-state creep rate were studied over a temperature range of and stress ranges of 200–225°C and stress range of 60–100MPa, and creep mechanisms corresponding to different conditions were proposed for the Mg–3Sm–0.5Zn–0.4Zr alloy.