TiAl单晶中〈011]超点阵位错滑移的临界分切应力(CRSS)与晶体取向的关系  

ORIENTATION DEPENDENCE OF CRSS FOR 〈011]SUPERLATTICE SLIP IN γ-TiAl SINGLE CRYSTALS

作　　者：吴东海[1,2] 吴东海[1,2] 胡赓祥[1] 乾晴行 山口正治 

机构地区：[1]上海交通大学材料科学系,上海200030 [2]上海宝山钢铁集团公司,上海201900 [3]京都大学工学部

出　　处：《金属学报》1999年第4期337-342,共6页Acta Metallurgica Sinica

基　　金：日本文部省资助

摘　　要：γ—ＴｉＡｌ单晶中，＜０１１］超点阵位错的运动方向同晶体取向有关、当沿极射投影图００１一１１０—０１０单位三角形的００１－１１１－０２１区域中的取向变形时，ＳＩＳＦ偏位错为领先位错；而沿三角形中其余区域中的取向变形时，ＡＰＢ偏位错为领先位错．在反常温度区域中（即超点阵位错开动的温度范围内），前者的ＣＲＳＳ较高，形变的热激活焓也较高，＜０１１超点陈位错的脱钉过程更为困难，造成ＣＲＳＳ反常上升的速率较快．The direction of motion for <011] superlattice dislocations in ac-TiAl single crystalsdepends on the crystal orientation. SISF super-partials become leading partials when the orientation ofloading axis is in the 001-111-021 region of the 001 -110-010 unit triangle of the sterographic projection,while APB super--partials become the leading partials with loading axis orientation in the other regionof the unit triangle. Below the peak temperature of yield stress, the correspondent CRSS for superlatticeslip is relatively higher in the SISF case than in the APB case, the unlocking process of <011] superlatticedislocation is more difficult for the SISF case with higher thermal-activation enthalpy, thus resulting inthe increase of CRSS.

关 键 词：γ-TiAl单晶 临界分切应力 热激活焓 晶体取向 

分 类 号：TG111.2[金属学及工艺—物理冶金] TG146.2[金属学及工艺—金属学]