MECHANICAL PROPERTY OF A NEW Zr-BASED BULK METALLIC GLASS WITH CERTAIN PLASTICITY AT LOW TEMPERATURE

摘要

The mechanical property of a new bulk metallic glass Zr50.7Cu28Ni9Al12.3, which owns 5% room-temperature plasticity, is investigated at low temperatures 193K and 123K. It is indicated that the yield strength and the plasticity significantly increase by 12.8% and 50% respectively as testing temperature is lowered from 298K (at room temperature) to 123K (in liquid nitrogen). The dense and multiple shear bands which contribute to the improved ductility are observed on the side surface of these samples fractured at low-temperature. Detailed study of the stress-strain curves for the samples deformed at low temperature show that more serrations and smaller stress drop form due to generation of more much shear bands.