不同锤锻方式下Ti-6Al-4V合金组织及取向演变

发布时间：2018-11-07 09:17

【摘要】：利用扫描电镜和背散射衍射技术研究了Ti-6Al-4V合金在不同锤锻变形方式下的组织与取向变化.结果显示:随着镦拔变形次数的增加,Ti-6Al-4V合金中α相及β相组织均趋于均匀,而且两相的取向聚集越不明显;进一步热处理后,锻造过程中形变储存能得到释放,在释放过程中两相也会发生一定的倾转,轴向三次镦拔或者换向三次镦拔对组织均匀性改善明显.综合分析发现,密排六方结构的α相的取向分布对变形方式较敏感:原始棒材以及一次镦拔时,合金中α相的取向{0001}基面织构占了很大部分;随着镦拔次数增多,形变能增加,虽然{0001}基面滑移被抑制,但是{1010}、{1120}等柱面滑移以及{0111}、{1123}等锥面滑移得以开动,大幅地增加了取向的种类,进而降低了取向的集中性,使得取向更趋均匀化.
[Abstract]:The microstructure and orientation of Ti-6Al-4V alloy under different hammer-forging deformation modes were studied by means of scanning electron microscopy (SEM) and backscatter diffraction technique. The results show that the microstructure of 伪 phase and 尾 phase in Ti-6Al-4V alloy tend to be uniform with the increase of the number of upsetting and drawing deformation, and the orientation aggregation of the two phases is less obvious. After further heat treatment, the deformation storage can be released during forging process, and the two phases will also be tilted in the process of release. The structure uniformity is improved obviously by axial three times upsetting or reversing three times upsetting. It is found that the orientation distribution of 伪 phase with dense hexagonal structure is more sensitive to the deformation mode: the orientation {0001} basal plane texture of 伪 phase in the alloy accounts for most of the original bar and the first upsetting drawing; With the increase of upsetting and drawing times, the deformation energy increases. Although the base slip of {0001} is suppressed, the slip of {1010}, {1120} and cone slip of {0111}, {1123} are activated, which greatly increases the types of orientation. Thus, the centrality of orientation is reduced, and the orientation becomes more uniform.
【作者单位】：北京科技大学材料科学与工程学院;
【分类号】：TG146.23;TG319

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