Microstructure evolution and plastic deformation of Ni47Co53 alloy under tension

Abstract

To investigate microstructural evolution and plastic deformation under tension, the rapid solidification processes of the Ni₄₇Co₅₃ alloy are first simulated by molecular dynamics methods at cooling rates of 10¹¹, 10¹² and 10¹³ K s⁻¹. Then, the uniaxial tension simulation study was conducted on a single crystal, polycrystal and metallic glass, which were formed during the rapid solidification. The results show that the dislocation loops evolution in the crystal is caused by the slips and proliferation of stacking faults, and in terms of plastic deformation, the single crystal is carried by stacking faults, while a polycrystal is carried by grain boundaries. A metallic glass formed at the critical cooling rate and crystallized under tension, the plastic deformation is carried by grain boundaries and stacking faults in metallic glass. Ultimately, the stacking faults are the most resistant to plastic deformation. This study has great significance for the study of the mechanical properties of single crystals, polycrystals and metallic glass.