Zr-Ni-Al金属ガラスの疲労せん断帯厚化の支配要因および形成条件

抄録

Metallic glasses (MGs) are materials in which atoms are arranged randomly over a long range. Therefore, MGs have superior mechanical properties such as high strength, low Young's modulus, high corrosion resistance, low coefficient of friction, and high transferability compared to crystalline materials. In previous studies, the shear band (SB) thickening occurring after the SB formation has been observed, and attributed to the intrinsic fatigue mechanism for MGs. However, the dominant factor for the thickening phenomenon has not been investigated and remains elusive. In this study, molecular dynamics (MD) simulation for monotonic compression, tension, and cyclic fatigue behavior was performed to investigate the fatigue mechanisms in Zr-Ni-Al metallic glass at the atomic-scale. The relationship between the strain range and SB formation and SB thickening phenomena was quantitatively explored by conducting several types of cyclic loading simulations. As a result, the relationship between the plastic strain range and SB thickening behavior was established.

Fig. 4　A sequence of snapshots monitored by local atomic shear strain under Tension-Compression fatigue test with a total strain range of 9.2％.