3338 分子動力学法を用いたアモルファス合金の有限変形挙動に及ぼす温度・ひずみ速度依存性(S18-5 アモルファス合金,S18 材料の強度と組織)

抄録

Amorphous metals have excellent mechanical properties such as high yield stress and high fracture toughness. However, they hardly exhibit the sufficient plastic elongation due to the localized deformation. To overcome such a defect, the localization mechanism must be resolved and the fracture criterion should be settled for future practical designing. In order to investigate the localization mechanism and to discuss the effects of the temperature and strain rate from the atomistic viewpoint, we construct the computational amorphous alloy models using molecular dynamics technique. Under a variety of environmental temperatures and loading rates, we performed the two-dimensional uniaxial tensile simulations. After large elastic elongation, the homogenous strain state immediately localize in shear deformation without any inelastic strain. These localized deformations, so called Shear band, largely depend on the strain rates and temperature.