The influence of thermo-mechanical loading on the mechanical behavior of Zr55Al10Cu30Ni5 bulk metallic glass was investigated experimentally. Pre-stressed specimen like loaded mechanical parts was subject to external and thermal load by heating. When pre-stress was lower than about 900MPa~1000MPa, during heating, this material showed plastic deformation with softening so that the mechanical tester cannot keep and control constant stress. A higher pre-stress than 1000MPa caused its brittle fracture to Zr55Al10Cu30Ni5 bulk metallic glass by heating. The temperatures to show these failures induced by heating under prestress to specimen were lower than the glass transition temperature of Zr55Al10Cu30Ni5 metallic glass measured by differential scanning calorimetry. Therefore, the interaction of the mechanical and thermal load such as external force and environmental temperature appears to decide the yield stress and the thermal properties of Zr55Al10Cu30Ni5 metallic glass, complementarily. From the result of this study, the direction for the strength design of applications made of this material subjected to various temperature conditions is indicated, and an effective machining method will be suggested.
