Effects of Zn and Ca addition on microstructure and mechanical properties of as-extruded Mg-1.0Sn alloy sheet
Effects of Zn and Ca addition on microstructure and mechanical properties of as-extruded Mg-1.0Sn alloy sheet
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Zn、Ca添加量对挤压态Mg-1.0Sn合金板显微组织和力学性能的影响
DOI：
10.1016/j.msea.2019.01.028
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发表时间：
2019-02-11
期刊：
影响因子：
6.4
通讯作者：
Pan, Fusheng
中科院分区：
文献类型：
--
作者：
Chai, Yanfu;Jiang, Bin;Pan, Fusheng
研究了挤压态Mg-1.0Sn、Mg-1.0Sn-0.5 zn、Mg-1.0Sn-0.7 ca和Mg-1.0Sn-0.5 zn -0.5 ca合金板材的室温组织和力学性能。结果表明：Mg-1.0Sn和Mg-1.0Sn-0.5 zn合金晶粒较粗，基底织构较强；Mg-1.0Sn-0.7 ca和Mg-1.0Sn-0.5 zn -0.5 ca合金晶粒细化明显，挤压方向（ED）分裂织构减弱；与Mg-1.0Sn合金相比，Mg-1.0Sn-0.5 zn合金的屈服强度和塑性分别提高了约20 MPa和5%。尽管Mg-1.0Sn-0.5Zn和Mg-1.0Sn-0.7Ca合金的塑性相似，但Mg-1.0Sn-0.7Ca合金的屈服强度提高更为显著。特别是Mg-1.0Sn-0.7 ca合金在横向拉伸下的屈服强度为209 MPa，比Mg-1.0Sn合金高约73 MPa。这主要是由于晶粒从26 μ m细化到9 μ m，以及均匀分布的球形Mg2Ca纳米颗粒诱导析出强化所致。此外，Mg-1.0Sn-0.5Zn-0.5Ca合金在ED拉伸下的延展性可达30.5%，几乎是Mg-1.0Sn-0.7Ca合金的两倍，这主要是由于棱柱滑移激活增加，晶界黏聚增强，晶间应变传播能力提高。因此，单独添加稀Zn或Ca有助于提高Mg-1.0Sn合金的强度和塑性，而稀Zn和Ca的联合添加为Mg-1.0Sn合金获得优异的塑性提供了新的途径。
The microstructure and mechanical properties of as-extruded Mg-1.0Sn, Mg-1.0Sn-0.5Zn, Mg-1.0Sn-0.7Ca and Mg-1.0Sn-0.5Zn-0.5Ca (all in wt%) alloy sheets were investigated and compared at room temperature. The results showed that the Mg-1.0Sn and Mg-1.0Sn-0.5Zn alloys exhibited relatively coarse grains and typical strong basal textures, whereas the Mg-1.0Sn-0.7Ca and Mg-1.0Sn-0.5Zn-0.5Ca alloys showed obvious grain refinement and weakened extrusion direction (ED)-split textures. The yield strength and ductility of the Mg-1.0Sn-0.5Zn alloy increased by approximately 20 MPa and 5%, respectively, than that of the Mg-1.0Sn alloy. Despite the similar ductilities of the Mg-1.0Sn-0.5Zn and Mg-1.0Sn-0.7Ca alloys, the yield strength improvement was more remarkable in the Mg-1.0Sn-0.7Ca alloy. In particular, the yield strength of the Mg-1.0Sn-0.7Ca alloy in tension along transverse direction was 209 MPa, which was about 73 MPa higher than that of the Mg-1.0Sn alloy. This was attributed mainly to the grain refinement from similar to 26 mu m to similar to 9 mu m and the precipitation strengthening induced by homogeneous distributed, spherical Mg2Ca nano-particles. Furthermore, ductility of the Mg-1.0Sn-0.5Zn-0.5Ca alloy in tension along the ED could reach up to 30.5%, which was almost twice that of the Mg-1.0Sn-0.7Ca alloy, because of increased activation of prismatic slip, enhanced grain boundary cohesion and improved intergranular strain propagation capacity. Therefore, individual addition of dilute Zn or Ca contributed to an improvement in the strength and ductility of the Mg-1.0Sn alloy, whereas combined addition of dilute Zn and Ca provided a new approach for achieving excellent ductility of the Mg-1.0Sn alloy.