Transfer and incorporation of dislocations to 3 tilt grain boundaries under uniaxial compression

単軸圧縮下の3粒界に対する転位の通過と反応

渋谷 陽二*; 廣内 智之*; 都留 智仁   

Shibutani, Yoji*; Hirouchi, Tomoyuki*; Tsuru, Tomohito

マクロな降伏現象は粒界を横切る転位の移動または粒界における残留転位と粒界近傍の転位の生成によって再現される。本研究では、運動転位に対する粒界の役割を規定する基準として、または'値を提案する。各種の傾角粒界に対するこれらの値を明記するとともに、実際に転位源を含む原子モデルを用いた単軸圧縮解析によって検証を行った。

Microscopic yielding can be realized by the transfer of a dislocation across a grain boundary (GB), or by incorporation between the residual GB dislocation and the dislocations nucleated in the near-field of a GB due to the applied stress. In the present paper, a new boundary interaction criterion of - or '-value is proposed, which considers both the contributions of the geometric relationship between two grains and a GB, and the stress state applied to the near-field of a GB. This value and the others so far proposed were calculated for 110, 100, and 111 symmetric tilt grain boundaries under uniaxial compression normal to the GB. The dynamic transfer and incorporation of the dislocations nucleated under uniaxial compression normal to the GB plane were then examined using 3-dimensional molecular dynamics simulations.