论文部分内容阅读
研究了Ti-2Al-2.5Zr合金的高温(673K)低周疲行为,结果表明:Ti-2Al-2.5Zr合金的循环变形表现出初始硬化、随后软化和最后二次硬化的特征。在高温和较高应变幅((Δε_t/2)>1.0%)条件下,材料的疲劳寿命高于室温下的疲劳寿命。随着应变幅的提高,高温673 K材料疲劳变形后形成的位错组态由位错墙逐渐演变成成熟的位错胞。多系滑移开动和塑性变形均匀性增强是高温Ti-2Al-2.5Zr合金疲劳寿命提高的原因。
The high temperature (673K) low cycle fatigue of Ti-2Al-2.5Zr alloy was studied. The results show that the cyclic deformation of Ti-2Al-2.5Zr alloy shows initial hardening, softening and final secondary hardening. At high temperature and high strain amplitude (Δε_t / 2)> 1.0%), the fatigue life of the material is higher than the fatigue life at room temperature. With the increase of strain amplitude, the dislocation configuration formed by the fatigue deformation of high temperature 673 K material gradually evolved from dislocation wall to mature dislocation cell. Multi-system sliding start and plastic deformation uniformity enhancement is the reason for the high temperature Ti-2Al-2.5Zr alloy fatigue life increase.