Abstract
The understanding of the fracture mechanism of amorphous alloys (AAs) is of importance for their engineering applications as advanced structural materials. In this study, a series of micro-tensions of Cu_(45)Zr_(45)Co_(10) AA microwires were conducted under different strain rates ranging from 5 x 10~(-5)s~(-1) to 1 x 10~(-2)s~(-1). It is found that all microwires fracture by shear cracking, but the shear fracture strengths exhibit pronounced rate-dependent uncertainties. Based on both lognormal and Weibull statistical analyses, the studied AA microwires reveal a positive rate-sensitivity of fracture strengths. However, increasing strain rates incurs the decrease in the fracture reliability. We demonstrate that the fracture reliability of AA microwires is dominated by a square root singularity of the characteristic lengths of shear offset on fracture surfaces, which satisfies linear elastic fracture mechanics.
NSTL
Elsevier