Preparation and characterization of Mo/ZrO2-Y2O3 composites

Mo/ZrO2-Y2O3 composites were successfully prepared through high-energy ball milling and powder metallurgy technique. The morphologies of the composite powders, the microstructures and properties of the sintered compacts and rotary swaged compacts were studied. The results show that ZrO2 addition refined the grains of composite powders and Mo alloys by promoting grains nucleation and inhibiting grains growth. Tetragonal zirconia (t-ZrO2) was completely stabilized at room temperatures by Y2O3 and evenly distributed in the molybdenum matrix. Moreover, ZrO2 was bonded with Mo matrix by an interfacial bonding zone. All above microstructures improve the mechanical properties and recrystallization temperature of the composites. The added values of yield strength, tensile strength and elongation of the doped Mo alloys after annealing all exceed 30% at room temperature, compared with pure Mo. ZrO2 particles make an effect on dispersion strengthening and improving recrystallization temperature by hindering dislocations movement.