摘要
利用Gleeble-3500热模拟试验机,在温度为300~420℃、应变速率为0.000 5~0.500 0 s^(-1)条件下对AZ80+0.4%Ce变形镁合金进行热模拟实验,研究该合金的高温流变行为。用ZIESS PL-A662数码光学显微镜分析温度与应变速率对合金显微组织演化规律的影响。结果表明:应变速率一定时,流变应力随温度的升高逐渐降低;变形温度一定时,合金的流变应力随应变速率的增大而升高。合金的显微组织演化过程为变形温度较低时,存在大量未结晶的粗大晶粒,动态再结晶进行不完全,温度升高后,动态再结晶进行较完全;动态再结晶晶粒尺寸随应变速率的增加而减小。最后,以经典的Arrhenius本构关系模型为基础,采用线性回归方法建立AZ80+0.4%Ce变形镁合金的流变应力本构模型,对比峰值应力的实验值与计算值,平均相对误差仅为6.00%。
The thermal simulation test of the AZ80+0.4%Ce wrought magnesium alloy was carried out at temperatures range from300 to 420 ℃ and strain rates range from 0.000 5 to 0.500 0 s^(-1)by using Gleeble- 3500 thermal simulation machine. The microstructure evolution with temperature and strain rate was analyzed by using ZEISS PL-A662 digital optical microscopy. The results show that the flow stresses decrease with the increase of temperature at a certain strain rate. Incomplete dynamic recrystallization tends to occur at lower deformation temperature,which is characterized by the coexistence of fine dynamic recrystallized grains and coarse original grains. The dynamic recrystallization tends to be more complete at higher temperature.Grain size decreases with increasing strain rate. Finally,based on the classical Arrhenius constitutive relationship model,a flow stress constitutive relationship model of AZ80 + 0.4% Ce wrought magnesium alloy was established by the linear regression method. Comparing the experimental and calculated values of peak stress,the average relative error is only 6.00%.
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2016年第6期35-40,共6页
Ordnance Material Science and Engineering
基金
基金项目:新世纪优秀人才(NCET-13-1001)
