Deforamtion and fracture behavior of Zr-based bulk amorphous metal under quasi-static compression

The deformation and fracture behaviors of a bulk amorphous metal, Zr-based one (Zr_41.2Ti_13.8Cu_12.5 Ni₁₀Be_22.5: Vitreloy), were investigated over a strain rate range (7×10^-4∼4 s^-1). The uniaxial compression test and the indentation test using 3mm-diameter WC balls were carried out under the quasi-static loading condition. As a test result, at the uniaxial compression state, the fracture strength of the material was ∼1,700MPa and the elastic strain limit was about 2%. The fracture strength showed a strain rate independent behavior up to 4 s^-1. Using indentation tests, the plastic deformation behavior of the Zr-based BAM up to a large strain value of 15% could be achieved, even though it was the deformation under locally constrained condition. The Meyer hardness of the Zr-based BAM measured by static indentation tests was about 5 GPa and it revealed negligible strain hardening behavior. At indented sites, the plastic indentation occurred forming a crater and well-developed multiple shear bands were generated around it along the direction of 45° when the indentation load exceeded 7kN. With increasing indentation load, shear bands became dense. The fracture surface of the specimen after uniaxial compressive tests showed vein-like pattern, typical morphology of many BAMs.