ヘテロナノ組織チタンの粒界から発生する変形モードの負荷方向依存性

抄録

In this study, the loading direction dependence of deformation modes activated from grain boundaries in heteronanostructured pure titanium was studied using molecular dynamics. Based on the observed texture of hetero-nanostructured titanium, a bicrystal model with Σ15 (tilt angle is 79°) grain boundaries is adopted. The crystal orientations are 〈1010〉, 〈1120〉, 〈0001〉 for TD, RD and ND respectively. Uniaxial tensile and compressive deformations in the TD, RD and ND directions are performed. As results, basal slip, deformation twinning and prism slip are observed. Basal slip appears under TD tensile and ND compressive deformations. {1121} deformation twinning appears under TD compressive and ND tensile deformations. Prism slip appears under RD tensile remarkably. The loading-direction dependence of activated deformation modes is originated from the grain boundary structure: basal slip and {1121} deformation twin are generated from the structural unit, but prism slip cannot utilize the structure unit.