Crystal rotation and microstructures in an aluminum single-slip system under tensile loading

単結晶のとの角度が引張荷重方向に対して45°である、アルミニウム単すべり系の(220)面の回転角度を実験的に調査した。SPring-8のBL28B2における放射光白色X線を利用し、とに沿ったいくつかのスポット（50×50μm）について結晶回転を調査した。負荷ひずみε=5%において、軸に沿った測定では垂直面の(220)面の結晶回転が、0.9mm～1.4mmの範囲で、0.850°～5.438°まで相対的に増加していた。さらに透過型電子顕微鏡を利用し、に沿った各スポットの転位セルや亜結晶粒のサイズを確かめた。この研究で明らかにされる基本的な局所結晶学は、材料の延性損傷を評価する方法として確立するために有効である

Crystal Orientation Dependence on Deformation Localization and Ductile Fracture in FCC Tri-Crystal Materials

On the basis of shock wave theory one of the author derived that the micro-crack nucleation is caused by the jump of the velocity along the intersected crossing line between two different stationary discontinuity bands characterized by vanishing velocity of an acceleration wave. In the previous paper, to consider dependence of the progress of ductile fracture of crystal solids on crystal orientations, the algorithm of acoustic tensors derived from the proposed model was built into finite element crystal plasticity model (FEPM) and the progress of ductile fracture in FCC bi-crystal was analyzed. In particular, the role of the crystal orientation and the grain boundary in the trigger of the transcrystalline fracture or intercrystalline fracture was examined. In this paper, the role of the crystal orientation and the grain-boundary triple junction in the trigger of the ductile fracture is studied and then the correlation between the progress of the ductile fracture and the amount of the jog caused by intersected cross slides of the dislocation slips is examined from the viewpoint of deformation controlled and/or diffusion controlled processes