Effects of Ca, Ag addition on the microstructure and age-hardening behavior of a Mg-7Sn (wt%) alloy
Effects of Ca, Ag addition on the microstructure and age-hardening behavior of a Mg-7Sn (wt%) alloy
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%20of%20Ca、%20Ag%20添加%20对%20%20显微组织%20和%20时效硬化%20行为%20of%20a%20Mg-7Sn%20(wt%)%20合金
DOI：
10.1016/j.msea.2017.03.066
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发表时间：
2017-04-24
期刊：
影响因子：
6.4
通讯作者：
Huang, Weigang
中科院分区：
文献类型：
--
作者：
Li, Wandong;Huang, Xuefei;Huang, Weigang
本文研究了Mg-7Sn、Mg-7Sn-lCa和Mg-7Sn-lCa-lAg合金的显微组织和时效硬化行为。结果表明，Mg-7Sn合金中Ca和Ag的联合添加对Mg-7Sn合金的晶粒细化有积极的作用，Mg-7Sn-1Ca-1Ag合金的晶粒尺寸从113.5 μ m细化到54.3 μ m。同时，由于Ag元素抑制CaMgSn相的形成和生长，CaMgSn相的尺寸被细化。CaMgSn相的平均长度从27.2 μ m减小到14.9 μ m。与Mg-7Sn和Mg-7Sn-lCa合金相比，Mg-7Sn-lCa-lAg合金具有最高的时效硬化响应。通过200 ℃时效处理，峰值时效硬度值从61.1 HV增加到80.4 HV，并且时效硬化响应的孕育期也随着Ag的添加从80 h缩短到20 h。这是由于Mg-7Sn-1Ca-1Ag合金中弥散析出相的有效促进和Mg_2Sn相体积分数的增加，使α-Mg基体产生了较强的沉淀强化作用。
The microstructure and age-hardening behaviors of Mg-7Sn, Mg-7Sn-lCa and Mg-7Sn-lCa-lAg alloys have been investigated in this study. The results show that the combined addition of Ca and Ag in Mg-Sn alloy has a positive effect on grains refinement from 113.5 mu m of Mg-7Sn alloy to 54.3 mu m of Mg-7Sn-lCa-lAg alloy. Meanwhile, the size of CaMgSn phase is refined due to suppressing the formation and growth of CaMgSn phase by Ag element. The average length of CaMgSn phase decreases from 27.2 to 14.9 mu m. Compared with Mg-7Sn and Mg-7Sn-lCa alloys, Mg-7Sn-lCa-lAg alloy exhibits the highest age-hardening response. The peak-aged hardness value increases from 61.1 HV to 80.4 HV by ageing treatment at 200 degrees C and the incubation period of age-hardening response also shortens from 80 h to 20 h with Ag addition. It is attributed to the effective promotion of dispersive precipitation and the volume fraction increasement of Mg2Sn precipitates in Mg-7Sn-1Ca-lAg alloy, which can lead to a strong precipitation strengthening effect in alpha-Mg matrix.