Zr계 벌크 비정질 복합재의 변형률 속도에 따른 인장 변형 거동 연구

Abstract

Tensile deformation behavior with different strain rate was investigated. Zr56.2Ti13.8Nb5.0Cu6.9Ni5.6Be12.5(bulk metallic glass alloy possessed crystal phase which was called β-phase of dendrite shape, mean size of 20~30㎛ and occupied 25% of the total volume) was used in this study. Maximum tensile strength was obtained as 1.74GPa at strain rate 102 s-1 and minimum strength was found to be 1.6GPa at 10-1 s-1. And then, maximum plastic deformation occurred at the strain rate of 5X10-2 s-1 and represented 1.75%, though minimum plastic deformation showed 0%. In the specific range of strain rate, relatively higher plastic deformation and lower ultimate tensile strength were found with lots of shear bands. The fractographical observation after tensile test indicated that vein like pattern on the fracture surface was well developed especially in the above range of strain rate