Influence of Thermoplastic Deformation Conditions on Strength Properties of Zr60Cu25Al10Ni5 Bulk Metallic Glass at Room Temperature
Takamasa YOSHIKAWA , Tadashi INABA and Masataka TOKUDA
Abstract:The influence of thermoplastic deformation on the mechanical properties of Zr60Cu25Al10Ni5 bulk metallic glass (BMG) at room temperature was studied experimentally. The strength of this BMG at room temperature after thermoplastic deformation can be decreased with deformation under a hot condition, even if the thermal condition does not exceed the specific TTT curve of this material and does not induce crystallization with embrittlement. It is supposed that the crystallization is caused not only by thermal condition but also by plastic deformation, and induces the decrease in the strength and embrittlement. Therefore the increase in the thermoplastic strain tends to promote the crystallization, and decrease the fracture stress at room temperature. However, it is confirmed experimentally that a high strain rate and low temperature is effective to avoid the decrease in the fracture stress at room temperature although the thermoplastic strain increases. Key Words:Bulk metallic glass, Thermoplastic deformation, Fracture stress, Room temperature, Amorphous, Crystallization