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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.
The microstructures and orientation changes of Ti-6Al-4V alloy under different forging deformation modes were studied by scanning electron microscopy and backscattering diffraction. The results show that with the increase of the number of upsetting deformation, α-phase And β-phase structure tend to be uniform, and the less obvious the two-phase orientation aggregation; after heat treatment, the deformation storage can be released during the forging process, the two phases will also be tilted in the release process, the axial three upsetting The results showed that the orientation distribution of the α phase of hexagonal close packed hexagonal structure is more sensitive to the deformation mode: when the original bar and the primary upsetting, the orientation of α phase in the alloy { 0001} basal topography account for a large part of the deformation; as the number of upsetting increases, the deformation can increase, although {0001} basal plane slip is suppressed, but {1010}, {1120} cylinder slip and {0111 }, {1123} and other cone slippage to start, greatly increased the type of orientation, thereby reducing the orientation of the concentration, making the orientation more uniform.