摘要
非共格孪晶界(ITB)能显著影响金属力学性能,受到了研究者极大关注.理论模型预测ITB是由系列偏位错组成,ITB两侧的晶面没有沿[111]方向的相对位移.本文利用分子静力学模拟研究了Ag,Cu,Ni和Al中ITB的结构,发现ITB的结构具有显著的尺寸效应.对于较薄的ITB,界面两侧的晶面处于同一水平面,没有沿[111]方向的相对位移,与理论模型结果一致.而对于较厚的ITB,界面两侧的晶面有明显的[111]方向的相对位移,且相对位移随着ITB厚度的增加而增加.此外,研究揭示出ITB两侧晶面沿[111]方向的位移与金属的层错能直接相关.该研究表明ITB的结构并不唯一,不同的厚度、层错能对应不同的ITB结构.本研究为理解孪晶厚度和层错能对金属力学性能的影响提供了新见解.
Twin-structured materials have garnered significant attention owing to their exceptional mechanical properties^([1,2]),such as ultrahigh strength^([3-5])and improved fatigue resistance^([6-8]).These mechanical properties are directly influenced by their atomic-scale structures.Consequently,numerous studies have investigated the atomic structures of twin boundaries(TBs)in face-centered cubic(FCC)metals.Among TBs,the coherent TB(CTB)is a special grain boundary(GB)with perfect symmetry and coherent structure.
作者
王占鑫
郭谊忠
马琰
杨成鹏
翟亚迪
燕鑫
王立华
韩晓东
Zhanxin Wang;Yizhong Guo;Yan Ma;Chengpeng Yang;Yadi Zhai;Xin Yan;Lihua Wang;Xiaodong Han(Beijing Key Laboratory of Microstructure and Properties of Advanced Materials,Beijing University of Technology,Beijing 100124,China;School of Mechanical Engineering and Automation,Beihang University,Beijing 100191,China)
基金
supported by the National Key R&D Program of China(2021YFA1200201)
Beijing Outstanding Young Scientists Projects(BJJWZYJH01201910005018)
the National Natural Science Foundation of China(12174014,12372106)
the Fundamental Research Funds for the Central Universities(YMF-22-L-808)。
