Compressive fracture characteristics of Ni42Cu5Ti19Zr22.5Al8Si3.5 bulk metallic glass

The uniaxial compressive fracture behavior of Ni42Cu5Ti19Zr22.5Al8Si3.5 bulk metallic glass (BMG) was investigated. It was found that the 2 mm rod exhibited a high fracture strength of 2851 MPa and plastic strain of 0.5%, while the 3 mm sample showed a fracture strength of 2724 MPa and nearly zero plastic strain. The property difference in the two samples was explained due to different structure caused by different cooling rates in glass formation. The compressive fracture surfaces of the deformed samples consisted of a flat shear zone and a coarse zone. The compressive fracture angles between the stress axis and the fracture plane changed from <45 to 90° as the fracture proceeded, suggesting that the compression fracture mechanism of the alloy might be understood in terms of the ellipse criterion.