摘要
利用扫描电镜电子通道衬度（ＳＥＭ－ＥＣＣ）技术，对单滑移取向疲劳Ｃｕ单晶从基体脉络位错结构到驻留滑移带（ＰＳＢｓ）位错结构的演化进行了观察．且对这个演化过程中典型的位错结构进行了模拟计算，给出了ＰＳＢｓ演化过程中典型位错结构内应力场的分布．结果表明：在从基体脉络位错结构到ＰＳＢｓ位错结构的演化过程中，内应力的分布是不均匀的，位错密集区域（基体脉络和ＰＳＢｓ墙中）比位错贫乏区域（通道中）平均内应力分布相对集中，ＰＳＢｓ夹层与基体相比平均内应力的分布相对较弱，ＰＳＢｓ与基体边界处存在很大的应力差．由观察和计算结果对ＰＳＢｓ演化给出了一个新的可能的演化机制．
The evolution from the so-call matrix vein to persistent slip bands (PSBs) in a fatigued copper single crystal of single-slip-oriented has been investigated by using electron channeling contrast (ECC) technique in a scanning electron microscope (SEM). The distribution of the internal stress field of typical dislocation structures in consecutive stages of PSBs formation was calculated by the method of discrete dislocation distribution. The results show that the distribution of internal stress is non-uniform in the evolution process from matrix vein to PSBs dislocation structures. In the dislocation dense regions (matrix vein and PSBs walls) the distribution of the internal stress is relatively more concentrated than that in the dislocation poor regions (channel). In a PSB the internal stress distribution is apparently weaker than that in matrix after the PSBs well formed. At the interface between PSBs and matrix, the stresses have a sharp transition. Finally a possible mechanism for PSBs formation was proposed.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2001年第5期507-511,共5页
Acta Metallurgica Sinica
基金
国家重大基础研究项目G20000671
G19990680
自然科学基金项目59971058资助
关键词
疲劳Cu单晶
驻留滑移带的演化
内应力场
位错结构模拟
fatigued copper single crystal
evolution of persistent slip band
internal stress field
simulation of dislocation structure
