Compressive deformation of Mg-Zn-Y-Zr alloy processed by equal channel angular pressing
Compressive deformation of Mg-Zn-Y-Zr alloy processed by equal channel angular pressing
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DOI：
10.1016/j.msea.2006.09.160
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发表时间：
2008-06
期刊：
影响因子：
6.4
通讯作者：
M. Zheng;S. W. Xu;X. Qiao;K. Wu;S. Kamado;Y. Kojima
中科院分区：
文献类型：
--
作者：
M. Zheng;S. W. Xu;X. Qiao;K. Wu;S. Kamado;Y. Kojima
采用等通道转角挤压（ECAP）工艺，在473 K下挤压8道次，制备了晶粒尺寸约为0.8μm的超细晶Mg-Zn-Y-Zr镁合金。在423 K的温度和1.67×10− 3至1.67×10− 1 s −1的应变速率下，对挤压态和进一步ECAP处理的Mg-Zn-Y-Zr合金进行压缩测试。在UFG ECAP处理的镁合金中，应变硬化速率极低，与挤压合金的应变硬化速率相反。ECAP处理的合金的超细晶粒在压缩中是稳定的，因为在合金中存在分散的细I相和沉淀物，这限制了晶粒的生长。ECAP处理的合金表现出更高的应变速率敏感性指数比挤压镁合金，这可能有助于其增强的延展性。
An ultrafine-grained (UFG) Mg–Zn–Y–Zr magnesium alloy with a grain size of about 0.8μm was produced by subjecting the extruded alloy to equal channel angular pressing (ECAP) for eight passes at 473K. Compressive testing was performed on the as-extruded and on the further ECAP-processed Mg–Zn–Y–Zr alloy at a temperature of 423K and under strain rates from 1.67×10−3to 1.67×10−1s−1. In the UFG ECAP-processed magnesium alloy, the strain hardening rate was extremely low, in contrast to that of the extruded alloy. The ultrafine grains of the ECAP-processed alloy were stable in compression because of the presence of the dispersion of a fine I-phase and of precipitates in the alloy, which restricted grain growth. The ECAP-processed alloy exhibited a higher strain rate sensitivity exponent than the as-extruded magnesium alloy, which may have contributed to its enhanced ductility.