当前位置: X-MOL 学术Acta Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Glide and cross-slip of a -dislocations in Zr and Ti
Acta Materialia ( IF 8.3 ) Pub Date : 2018-08-01 , DOI: 10.1016/j.actamat.2018.05.038
D. Caillard , M. Gaumé , F. Onimus

Abstract Slip systems involving dislocations with Burgers vectors have been studied in hexagonal close packed Zr and Ti, by means of in situ straining experiments in a transmission electron microscope, at various temperatures and as a function of resolved shear stress. The results show that Zr and Ti are very similar in many respects. Prismatic slip is activated at rather low resolved shear stresses, and is controlled by the interaction between mobile dislocations and solute atoms (presumably oxygen). Pyramidal slip requires substantially higher resolved shear stresses and is characterized by straight screw dislocations moving by a kink-pair mechanism. Basal slip is activated at and above room temperature, for resolved shear stresses equal or higher than those in the prismatic planes. The slip traces are always wavy, presumably due to intensive cross slip from basal to prismatic planes. It also involves straight screw dislocations moving by a kink-pair mechanism. These microscopic observations are discussed in the light of some aspects of the mechanical behavior, in particular the increase of yield-stress at decreasing temperature and the discontinuity of activation area close to room temperature.

中文翻译:

Zr 和 Ti 中 a -位错的滑移和交叉滑移

摘要 通过透射电子显微镜中的原位应变实验,在不同温度下,作为解析剪切应力的函数,研究了在六角密堆积 Zr 和 Ti 中涉及具有 Burgers 向量的位错的滑移系统。结果表明Zr和Ti在许多方面非常相似。棱柱滑移在相当低的解析剪应力下被激活,并受移动位错和溶质原子(可能是氧)之间的相互作用控制。锥体滑移需要显着更高的解析剪应力,其特征在于通过扭结对机制移动的直螺旋位错。基底滑移在室温及以上被激活,解析剪切应力等于或高于棱柱平面中的剪切应力。滑痕总是波浪状的,大概是由于从基面到棱柱面的强烈横向滑移。它还涉及通过扭结对机制移动的直螺旋位错。这些微观观察是根据机械行为的某些方面进行讨论的,特别是在降低温度时屈服应力的增加和接近室温的活化区域的不连续性。
更新日期:2018-08-01
down
wechat
bug