The Synthesis Of ZrO₂/Zr-Based Bulk Metallic Glass Composites And Study Of Their Mechanical Properties

By using techniques of copper mold casting and powder hot-pressed forming, ZrO₂ /Zr-based bulk metallic glass (BMG) composites have been fabricated, and the mechanical properties of ZrO₂ /Zr-based BMG composites have been studied in this paper.The particle of ZrO₂ would react with the element Y when the arc melting technique was used to prepare ZrO₂/ Cu₄₆Zr₄₂Al7Y5 composite ingot. As a result, the structure of the composite after copper mold casting was amorphous matrix reinforced by Y2O3 particles.The compressive failure strength of the composites increased because of the reinforcement of Y2O3 particles and the compositional variation of the amorphous matrix.The ZrO₂/ Zr55Cu₃₀Al₁₀Ni5 BMG composites prepared by copper mold casting contained some quenched-in crystalline phase, because the oxygen induced by the ZrO₂ particles increased the critical cooling rate by inducing crystalline precipitation and hence narrowing supercooled liquid region and decreasing the thermal stability of the metallic glass composites. The mode of fracture changed from ductile to fragile for the BMG composites, but the compressive failure strength increased.The ZrO₂/Zr-based BMG composites were successfully prepared by powder hot-pressed forming method, since it weakened the reaction between ZrO₂ and element Y, and reduced the sensibility of oxygen for the amorphous matrix. The method of hot-pressed forming exhibits more advantages in preparing ZrO₂/Zr-based bulk metallic glass composites than copper mold casting.