摘要
在420℃～650℃的温度范围内，实验研究了FGH95粉末高温合金在应变率0．0001s^-1～0．01S^-1范围内的拉伸一断裂性能，分析了温度和应变率对该合金流动应力的影响，结果表明，应变率对杨氏模量、拉伸屈服强度和塑性模量的影响不是很大，随着应变速率的增大和温度的升高，合金的塑性流动应力有所提高，断裂强度和断裂韧性增强。并通过流动应力与应变、应变率和温度之间的函数关系，分别讨论了硬化指数咒、应变速率敏感系数m及应力相关系数K与温度ε和应变率；的函数关系。SEM断口分析表明FGH95合金是微缺陷敏感材料，在高温（420℃-650℃）应变率范围为10^-4s^-1～10^-1s^-1时的拉伸断裂都是韧性断裂。
Tensile performance tests were carried out on powder metal（PM）FGH95 at strain rates ranging from 10^-4 s^-1 to 10^-1 s^-1 and over temperatures ranging from 420℃ to 650℃. Emphasis was put on the effect of strain rate and temperature on the plastic flow stress. Experimental results show that the effect of strain rate on the Young/s modulus, tensile yield strength, and plastic modulus can be neglected within temperature range from 420℃ to 650℃. Plastic flow stress, fracture stress and fracture toughness increase along with the strain rate and temperature increasing. The relations between hardening exponent n, strain rate sensitivity index m, stress coefficient K, temperature T and strain rate ε were investigated respectively by the equation of a= Kεnε^m. The SEM results show that the fracture mode of all specimens is tough within temperature range from 420℃ to 650℃ with strain rate range from 0. 0001s^-1 to 0.01s^-1. The PM FGH95 was sensitive to the micro-defect, which has a significant deleterious effect on material mechanical behavior of FGH95.
出处
《实验力学》
CSCD
北大核心
2008年第5期411-416,共6页
Journal of Experimental Mechanics
基金
国家自然科学基金(10472094
50375124)资助项目
国防科技工业项目技术基础科研项目(Z142006B001)
博士点基金(N6CJ0001)
