中文摘要：

利用电子背散射衍射（EBSD）对采用90°模具以C方式制备的等径弯曲通道变形（ECAP）各道次工业纯钛（CP-Ti）试样的组织及织构演变进行表征。结果表明：1道次变形后,ECAP组织并不均匀,既有拉长的粗晶,又有细小的等轴晶。随着道次的增加,组织变得细小均匀,从而达到细化晶粒的效果;工业纯钛ECAP变形初始阶段,粗大的晶粒破碎,产生位错缠结和位错胞,使小角度晶界增加。随着道次的增加,位错不断地向亚晶界运动,亚晶间产生相对滑动和转动,最终形成具有大角度晶界的超细晶组织,使小角度晶界减少,大角度晶界增加。工业纯钛原始试样具有双峰基面织构,晶体的c轴由法向方向（ND）向挤出方向（ED）偏转约15°,4道次变形后变为剪切织构,晶体的基面与剪切面平行,最终形成织构组分为（1120）[1101]。

英文摘要：

The microstructure and texture developments of CP-Ti during equal-channel angular pressing（ECAP） using 90° die via route C were investigated by electron backscatter diffraction（EBSD） technique. The results showed that after the first pass the typical ECAP microstructures consisted of elongated coarse grains and fine-equiaxed grains. With the increase of ECAP passes, the microstruc- ture became more homogeneous and fine, which achieved the effect of fine grain ; in the initial ECAP of CP-Ti, the coarse grains were broken and formed dislocation tangles and dislocation cells, so the fraction of low-angle boundarys increased. With the increase of ECAP passes, the dislocation moved to the grain boundary, subgrains slided and rotated with each other. Finally ultra-fine grains with high angle grain boundary formed. The fraction of low-angle boundarys decreased and the fraction of high-angle boundarys increased. The texture of hot rolling CP-Ti was of two peaks basal plane texture, of which most c-axis of grains tilted about 15° from normal direc- tion（ND） to extrusion direction （ED） ; after 4 ECAP passes, the texture changed to ECAP shear texture, of which most basal planes were parallel to shear plane, and the finally formed texture was （1120） [ 1101].