摘要
在温度为400～440℃、应变速率为10^-2～10^-4s^-1。的范围内研究AZ31镁合金的超塑性。结果表明，当应变速率不小于5×10^-3s^-1时，AZ31镁合金的超塑性伸长率随着温度的升高而增大。对应变速率敏感指数和拉伸试样的宏观断裂特征分析表明，应变速率敏感指数是影响超塑性的主要因素。当应变速率不大于5×10^-4s^-1时，AZ31镁合金在420℃时具有最大伸长率。对断裂试样的颈缩现象和断口空洞的SEM分析表明，空洞是影响超塑性的主要因素。
At the temperature between 400 ℃ and 440 ℃, tensile tests were conducted with strain rate between 10 ^-2 s ^-1 and 10^-4 s^-1 to investigate the superplasticity of AZ31 magnesium alloy. The results show that superplasticity ductility increases with temperature when strain rate is equal to or larger than 5 × 10^-3 s^-1. The analysis of the value of strain rate sensitivity exponent and fractured characteristics of tensile sample also finds that strain rate sensitivity exponent is the key factor that influences the elongation. AZ31magnesium alloy exhibits the highest ductility at 420 ℃ when strain rate is equal to or lower than 5 × 10^-4 s^-1. By analyzing the necked characteristic and the SEM photograph of the fractured area, it is concluded that cavitation is the key factor that influences the elongation of superplasticity.
出处
《武汉科技大学学报》
CAS
2008年第5期547-551,共5页
Journal of Wuhan University of Science and Technology
基金
湖北省教育厅重点资助项目(Z200511007)
关键词
AZ31镁合金
超塑性
应变速率敏感指数
空洞
AZ31 magnesium alloy
superplasticity
strain rate sensitivity exponent
cavitation
