固溶处理后预变形对 Ti-6Al-4V Alloy时效行为和机械性能的影响

Effect of Pre-deformation on the Aging Behavior and Mechanical Properties of Ti-6Al-4V Alloy

摘要:

本文研究了固溶处理后预变形对Ti-6Al-4V合金时效行为和机械性能的影响。结果显示在940 °C 和 955 °C固溶处理后进行预变形，可以提高时效过程中第二相α的析出。在940 °C固溶处理后，随着预变形量的增加，时效处理后第二相α含量增加，α相尺寸减小，合金的强度和硬度增加。在时效处理之前进行预变形可以明显提高合金的拉伸强度和硬度，也能同时保持比较好的韧性。相对固溶温度为940 °C来说， Ti-6Al-4V合金在955 °C固溶处理后进行预变形，对于提高合金的强度和硬度的效果不显著。本文采用扫描电镜对不同预变形和时效处理后的合金断口形貌进行了分析。

Abstract:

The effects of pre-deformation on the aging behavior and mechanical properties of Ti-6Al-4V alloy were studied. Results show that the addition of pre-deformation after the solution process at 940 °C and 955 °C is beneficial in promoting the precipitation of the secondary α phase during the aging of Ti-6Al-4V alloy. When solution temperature was 940 °C, the content of the secondary α phase increased with an increase in pre-deformation amount, its size decreased, and the strength and hardness of the alloy increased monotonously after aging. The tensile strength and hardness of Ti-6Al-4V alloy after aging were evidently higher with pre-deformation than without pre-deformation. Simultaneously, excellent plasticity was maintained. In the case with added pre-deformation, a solution temperature of 955 °C slightly improved the strength and hardness of Ti-6Al-4V alloy compared with a solution temperature of 940 °C. Scanning electron microscopy examinations indicate that the fracture modes of all aged alloys with varying pre-deformation degrees are ductile fracture.