纯钛室温ECAP和旋锻复合变形过程中的织构演变

Texture evolution of pure titanium during ECAP and rotary-swaging composite deformation at room temperature

采用等径弯曲通道挤压(ECAP)和旋锻(RS)复合工艺在室温下对纯钛进行大塑性变形,利用X射线衍射技术分析了纯钛室温ECAP和ECAP+RS复合变形过程中的织构演变规律。结果表明,随着室温ECAP变形道次的增加,原始基面织构逐渐向锥面织构和柱面织构转变,且织构强度减弱。室温ECAP变形过程中晶粒取向的变化主要以晶向绕TD轴的旋转为主,晶面旋转幅度较小。RS变形使得ECAP形变织构发生根本改变,柱面织构基本消失,形成以锥面织构和基面织构为主的形变织构,且织构强度显著增加。纯钛室温ECAP+RS复合变形过程中ODF图的演变是连续的,说明其塑性变形机制以位错滑移为主。

Large plastic deformation of pure titanium was carried out by equal channel angular pressing(ECAP)and rotary-swaging(RS) composite deformation at room temperature.The texture evolution of pure titanium during ECAP and ECAP+RS composite deformation at room temperature was investigated by X-ray diffraction(XRD) technology.The results show that with the increase of ECAP deformation pass,the initial basal texture gradually evolves to pyramidal texture and prismatic texture,and the texture strength decreases.The change of grain orientation is mainly that the crystal orientations rotate around the TD axis and rotation amplitude of crystal plane is small during the ECAP at room temperature.RS deformation changes ECAP deformation texture completely.The prismatic texture basically disappears and the main deformation textures are pyramidal texture and basal texture,and the texture strength increases significantly.The evolution of orientation distribution function(ODF) diagram during ECAP+RS composite deformation at room temperature is continuous,which means that its plastic deformation mechanism is mainly dislocation slip.