快速凝固 / 粉末冶金镁合金的压缩变形行为
Compressive Deformation Behavior of Rapidly Solidified / Powder Metallurgy Magnesium Alloy
周 涛1, 夏 华1, 杨明波1, 陈振华2
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作者单位：(1. 重庆理工大学 材料科学与工程学院, 重庆 400054; 2. 湖南大学 材料科学与工程学院, 湖南 长沙 410082)
中文关键字：快速凝固/粉末冶金； 镁合金； 变形行为； 力学性能
英文关键字：rapidly solidification/powder metallurgy; magnesium alloy; deformation behaviour; mechanical properties
中文摘要：采用雾化-双辊急冷法和热挤压工艺，成功地制备了快速凝固/粉末冶金(RS/PM)Mg-6wt%Zn、 Mg-6wt%Zn-
5wt%Ce和Mg-6wt%Zn-5wt%Ce-1.5wt%Ca合金，并对合金的压缩变形行为进行了研究， 其中测试温度为25～300 ℃，初始应变速率为5 × 10-4 /s。结果表明，合金的变形行为强烈依赖于变形温度。合金中细小、弥散的析出相为主要的非位错型障碍物，可能是造成合金硬化的主要原因；而随着温度的升高，软化机制的激活会引起合金变形行为的不同。其中，位错的交滑移、攀移以及晶界滑动可能是软化的主要原因。
英文摘要：Rapidly solidification / powder metallurgy (RS/PM) Mg-6Zn, Mg-6Zn-5Ce and Mg-6Zn-5Ce-1.5Ca (wt%) alloys in the form of rods were prepared by hot extrusion. The compressive deformation behavior of the magnesium alloy was studied at the temperature range of 25 ℃～300 ℃ and initial strain rate of 5 × 10-4 /s. The results show that the yield stress as well as the maximum stress of the alloy are very sensitive to testing temperature. The fine and dispersive precipitates in the alloys are the main non-dislocation obstacles, which are the main obstacles for the moving dislocations, hence, responsible for hardening. The cross slip, climb of dislocations and grain boundary slide may control softening in the alloys with the increase of temperature.