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利用聚焦离子束(FIB)对hcp结构金属α-Ti进行纳米尺寸单晶拉伸样品定向切割,利用特制的双金属片拉伸器在TEM中将单晶样品沿[2110]方向进行原位拉伸.结果表明,在拉伸过程中,随着应变量的增加,α-Ti先后产生了3类不同Burgers矢量的滑移位错:柱面位错及2类锥面位错,滑移位错的Burgers矢量主要通过原位TEM双束衍衬像确定.针对hcp结构的低对称性和Burgers矢量可能与多种滑移面相组合的特点,先利用TEM与EBSD确定晶体取向以及样品的拉伸方向,再通过计算位错Burgers矢量对应的多个滑移系的Schmid因子,确定α-Ti拉伸变形过程中开动的滑移系.
The oriented single crystal samples of α-Ti with hcp structure were oriented and cut by focused ion beam (FIB). In the TEM, a single-crystal sample was pulled in-situ by [2110] Stretching results show that α-Ti has three kinds of different Burgers vectors: the dislocation of the cylinder and the Burgers vector of dislocation and slip dislocation is mainly determined by in-situ TEM double-beam diffraction pattern.For the low symmetry of hcp structure and Burgers vector may be combined with a variety of slip planes, the first use of TEM and EBSD The orientation of the crystal and the orientation of the sample were determined. Then the Schmid factor of multiple slip systems corresponding to the dislocation Burgers vector was calculated to determine the slipping system that started during the α-Ti tensile deformation.