锻造方式对 Ti--6Al--4V 合金组织及取向分布的影响

在快锻液压机上对 Ti-6Al-4V 合金进行了锻造变形，采用扫描电镜、背散射电子衍射技术以及 X 射线衍射技术研究了不同锻造方式下合金组织及晶粒取向的变化规律。在单向镦拔和换向镦拔两种不同锻造方式下，难变形区、小变形区及大变形区中α相及β相的分布差别不大，组织均匀性基本一致，两种变形方式下锻坯不同区域的应变稍有差别。进一步对不同变形区域形变织构的定量分析可知：在应变较小的边缘区域，变形主要以{0001}基面滑移为主，形成基面织构；在应变较大的内部区域，织构明显转向{112

Effect of forging processes on the microstructure and texture distribution of Ti--6Al--4V alloy

The microstructure and texture evolution of Ti- 6Al- 4V alloy under different forging processes on a free forging hydrau-lic press were investigated by scanning electron microscopy, electron backscattered diffraction and X-ray diffraction. It is found that the microstructures of Ti- 6Al- 4V alloy under different forging modes, unidirectional forging and cross upsetting and stretching, are nearly the same. The distributions of α phase and β phase in the difficult deformation zone, small deformation zone and large deforma-tion zone are very similar, while the strain is distinctive in different forging regions. Further observations indicate that, in the edge re-gion with small strain, the slip system is mainly the {0001} basal plane and forms the basal texture, {112-0} and {101-0} prismatic textures occur in the internal high strain region, while {112-2} and {101-1} pyramidal textures appear in the place where the stress concentrates. The two forging processes can both improve the uniformity of deforming textures; in addition, cross upsetting and stretc-hing is better than unidirectional forging.