摘要
为了研究挤压态ZK60镁合金的热变形行为,利用Gleebe-3500热模拟机在变形温度为523~723 K、应变速率为0.01~10 s^（-1）的条件下对挤压态ZK60合金进行了热压缩变形试验。通过真应力-真应变曲线分析了挤压态ZK60合金流变应力与应变速率、变形温度之间的关系,通过引入Z参数建立了挤压态ZK60合金的流变应力本构方程,并观察了其在热压缩过程中的显微组织变化。结果表明：挤压态ZK60合金的真应力-真应变曲线属于动态再结晶型,并且合金的流变应力在高变形温度或低应变速率条件下较低。在变形温度降低或应变速率升高时,动态再结晶晶粒变小,但动态再结晶进行的不充分,再结晶晶粒分布不均匀。通过本构方程计算出挤压态ZK60镁合金的变形激活能Q=122.884 k J/mol,应力指数n=5.096。
In order to investigate the hot deformation behavior of extruded ZK60 magnesium alloy,compression test of the alloy was performed on a Gleebe-3500 thermal simulator at the temperature range of 523-723 K and the strain rate range of 0. 01-10 s^（-1）. The relationship between flow stress and strain rate as well as deformation temperature were analyzed by using the true stress-true strain curves. The constitutive equation for extruded ZK60 alloy was obtained by introducing the Z parameter. Microstructure evolution of extruded ZK60 alloy during hot compression deformation was observed. The results show that the true stress-true strain curves of extruded ZK60 alloy is of dynamic recrystallization type,and the flow stress of the alloy is lower at higher deformation temperature and lower strain rate. When the deformation temperature decreases or the strain rate increases,the dynamic recrystallization grain size become finer,but the dynamic recrystallization is not completed and the grain distribution is not uniform. Calculated by the constitutive equation,the deformation activation energy of extruded ZK60 magnesium alloy is Q = 122. 884 k J/mol,and the stress exponent is n = 5. 096.
出处
《金属热处理》
CAS
CSCD
北大核心
2018年第1期33-37,共5页
Heat Treatment of Metals
基金
山东省自然科学基金(ZR2015EQ019)
山东省轻质高强金属材料省级重点开放课题(2016sdlsm002)
关键词
ZK60镁合金
流变应力
热压缩变形
动态再结晶
ZK60 magnesium alloy
flow stress
hot compression deformation
dynamic recrystallization
