单晶Nb拉伸,压缩及恒应变疲劳后的滑移系和滑移特征

研究了单滑移位向和多滑移位向Ｎｂ单晶在拉伸，压缩及循环变形时的滑移系，根据试样表面滑移线的方向，在极图上确定滑移面，单滑移位向（［３２１］）的单晶，在拉伸时的滑移系为（１０１）［１１１］，在压缩时是（１０１）［１１１］和（２１３）［１１１］．根据ｂｃｃ晶体变形特点，分析了拉伸，压缩和循环变形的滑移系之间的关系，用光学显微镜和透射电镜复型观察了试样的表面形貌，确定了多滑移位向（［１１０］位向）单晶滑

SLIP SYSTEMS AND THEIR CHARACTERISTICS OF Nb SINGLE CRYSTALS UNDER TENSION, COMPRESSION AND CYCLIC DEFORMATION

The slip systems of Nb single crystals with single and multiple glide orientations have been investigated respectively under tension, compression and cyclic defomation. From the stereographic plots of the slip line directions measured around the specimen surface,the slip planes were determined. The slip system for the single glide orientation ([321] orientation) is(101) under tension, however in compression, it is(101) and (213) . The relationship of the slip systems activated by tensile,compressional and cyclic deforination was analyzed in accordance with the deformation features of bcc crystals. The surface topography of the specimens has been observed using optical microscope, SEM and TEM(replical).The activated sequence of the slip systems for the multiple slide orientation ([110] orientation) was therefore determined.