摘要
采用Gleebe-1500热/力模拟机研究了 Mg-5.6Zn-0.7Zr-0.8Nd合金在应变速率为0.1,0.01和0.002s^(-1)、变形温度为373—673K、最大变形程度60％条件下的高温塑性变形行为。分析了合金流变应力与应变速率、变形温度之间的关系,计算了高温变形时变形激活能和应力指数,并观察了合金变形过程中显微组织变化情况。结果表明:Mg-5.6Zn—0.7Zr-0.8Nd合金在热变形过程中不同温度下流变应力呈现不同形式,分析可知加工硬化、动态回复和动态再结晶在不同温度和不同应变速率下各自起到了重要的作用,合金变形激活能随应变速率增加而升高.在473K温度以上变形,合金发生明显动态再结晶且动态再结晶晶粒非常细小,晶粒尺寸为 5—10μm。
The plastic deformation simulation of Mg-5.6Zn-0.7Zr-0.8Nd alloy at elevated temperature was performed on Gleebe-1500 hot simulator with the strain rates 0.1, 0.01 and 0.002 s-1 over a temperature range from 373 to 673 K and the maximum deformation degree 60%. The relationships between flow stress and deformation temperature as well as strain rate were analyzed and the deformation activation energy and stress exponent were calculated. The variations of microstructure during the hot deformation process were observed. The results show that there are three types of flow stress at different temperatures. Working harden, recovery and recrystallization operate under different temperatures and strain rates. The deformation activation energy increases with increasing strain rate. The alloy dynamic recrystallizes during deforming over 473 K, and the recrystallized grain size is only 5-10μm, which improves the ductility of alloy
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第5期492-498,共7页
Acta Metallurgica Sinica
关键词
镁合金
塑性变形
热模拟
动态再结晶
magnesium alloy, plastic deformation, hot deformation simulation, dynamic recrystallization
