摘要
利用弯曲应力松弛方法研究了魏氏组织Ti-6Al-4V合金200℃,400℃和600℃时的应力松弛行为,并利用TEM研究了应力松弛前后微观组织变化;宏观热力学参数结合微观组织观察初步探讨应力松弛机理。研究表明:应力松弛开始时应力下降较快,随时间延长,应力下降速率降低,最后趋于应力松弛极限。TEM微观组织观察结果结合表观应力指数分析表明:200℃和400℃应力松弛变形机制为位错蠕变,a型位错滑移;而600℃变形机制则为回复蠕变和原子扩散的共同作用机制,a型和a+c型或c型均开动,产生滑移和攀移。
The stress relaxation behavior of Ti-6Al-4V alloy with widmanstatten microstructure at 200℃, 400℃ and 600℃were investigated, and microstructures before and after stress relaxation were observed by TEM. The results show that the stress decreased rapidly at the beginning of stress relaxation, but the stress relaxation rate decreased with the progress of relaxation time, the remained stress tended to stress relaxation limit. The TEM observation combined stress exponent showed the deformation mechanism is dislocation creep at 200℃ and 400℃, in which a type dislocation slide occurred; while recovery creep and atom diffusion at 600℃, in which both a and c or a＋c dislocation slide and climb occurred.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2005年第11期1766-1769,共4页
Rare Metal Materials and Engineering
