退火热处理对等径角挤压回收Ti-6Al-4V合金微观结构和显微硬度的影响（英文）

Effect of Annealing Treatment on Microstructure and Micro-hardness of Equal Channel Angular Pressing Recycled Ti-6Al-4V

采用等径角挤压法回收Ti-6Al-4V合金切屑,并研究了回收样品和退火处理样品的微观结构和显微硬度。结果表明:在回收样品中,切屑之间的边界依然存在,而由于剧烈塑性变形,超细晶结构和较强的纤维织构得以形成。退火处理后,切屑边界部分消失,超细晶组织部分再结晶;而与此同时,退火处理样品展现出更宽泛的织构,再结晶晶粒并不存在择优取向。值得注意的是,退火处理样品的显微硬度较回收样品略有升高。

The present study concerns the change in microstructure and micro-hardness induced by annealing treatment for Ti-6 Al-4 V machining chips recycled by using equal channel angular pressing（ECAP）.The microstructure exploration and micro-hardness tests upon the as-recycled Ti-6 Al-4 Vas well as the sample experienced subsequent annealing treatment were carried out.We observed that the prior chip boundaries remained in the recycled material,and the severe plastic deformation contributed to the formation of the ultrafine grained microstructure and a strong fibre-like texture.After annealing,the chip boundaries partially dissolved and the fine grains partially recrystallized.Meantime,the annealed material exhibited a weaker texture and a wider orientation distribution was found for the recrystallized grains.It is noteworthy that the micro-hardness remained essentially unchanged,even slightly increased for the recycled Ti-6 Al-4 Vafter heat treatment.