挤压温度对Mg-9Gd-4Y-0.6Zr合金组织与力学性能的影响

来源期刊：中国有色金属学报2006年第3期

论文作者：张新明 肖阳 陈健美 蒋浩

文章页码：518 - 523

关键词：镁合金； Mg-9Gd-4Y-0.6Zr合金； 挤压温度； Hall-Petch常数

Key words：magnesium alloy; Mg-9Gd-4Y-0.6Zr alloy; extrusion temperature; Hall-Petch constant

摘    要：为提高Mg-9Gd-4Y-0.6Zr合金的强度， 研究了不同温度下的挤压组织对合金力学性能的影响。 结果表明， 随着挤压温度从500 ℃降低到400 ℃， 其晶粒度也从126 μm细化到7.4 μm， 抗拉强度和延伸率分别从200.1 MPa和2.93%提高到312.4 MPa和5.6%。 通过力学性能和晶粒尺寸之间的关系计算出该合金的Hall-Petch常数K_y为327.6 MPa·μm^1/2， 明显高于纯镁及常规镁合金的K_y。 大量稀土元素的固溶及其第二相粒子对晶界和位错运动的阻碍作用是合金K_y值较高的主要原因。

Abstract: The influence of different extrusion temperatures on the microstructures and mechanical properties of Mg-9Gd-4Y-0.6Zr alloy was investigated. It is found that when the extrusion temperature descends from 500 ℃ to 400 ℃, the grain size drops from 126μm to 7.4μm, the tensile strength and elongation increase from 200.1 MPa and 2.93% to 312.4 MPa and 5.6%, respectively. The Hall-Petch constant (K_y=327.6 MPa·μm^1/2 ) calculated by the Hall-Petch equation for the alloy is markedly higher than that of pure magnesium and conventional magnesium alloys, which is caused by a great deal of dissolved rare-earths and their second-phase particles by which motions of grain boundaries and dislocations are effectively impeded.

基金信息：国家安全重大基础研究资助项目
国家高技术研究发展计划资助项目