90°模具室温4道次ECAP变形纯钛的宏观织构演变

Texture Evolution in Commercially Pure Titanium after ECAP Using a 90° Die at Room Temperature

采用两通道夹角Φ=90°,外圆角ψ=20°的模具,实现TA1纯钛C方式4道次室温ECAP（Equal Channel Angular Pressing）变形,制备了表面光滑无裂纹的变形试样。研究纯钛室温ECAP变形试样的织构演变特征。结果表明：在ECAP变形初期,基面织构和锥面织构逐渐向P（φ1=45°,φ=0°~90°,φ2=30°）织构旋转,基面织构和锥面织构减少,柱面织构增加,织构的演变是由位错增殖导致微结构变化引起的。在变形后期因晶粒细化,织构演变主要由整个晶粒的旋转来形成剪切织构,基面织构逐渐增加。

Commercially pure （CP） titanium （grade 1） was processed by equal channel angular pressing （ECAP） up to 4 passes via route C at room temperature using a die of Φ=90° and ψ= 20°. The as-processed CP-Ti billets were smooth and free of visible surface cracks. The texture evolution in CP-Ti after ECAP was investigated at room temperature. The results show that the basal and pyramidal textures gradually evolve to P （φ 1 =45°, φ=0°～90°, φ 2 =30°） texture. Basal and pyramidal textures are decreased, while prismatic texture is increased. Texture evolution in CP-Ti is caused by the dislocation multiplication in the early stage of ECAP deformation. In the later period of deformation, the shear texture is formed through the grain rotation and the basal texture is increased gradually due to grain refinement.