Deformation Mechanism of Nano-crystal at High Strain Rate

Y. Qi, H. Ikeda, T. Cagin, W. L. Johnson, W. A. Goddard


We used MD method at constant temperature, constant shape condition(ThN MD) to simulate the tensile test at constant strain rate, by increasing the unit length along z direction 0.5% every step. For a CuNi system, at a strain rate of 0.5%/ps, twins formed to release the elastic energy, and as the stain rate increased, the twin size decreased. When the strain rate reached 5%/ps, the crystal transformed to metallic glass and deformed uniformly. To understand the deformation mechanism in crystal, glass and liquid states of metals and alloys is the focus of the current work.