Preparation and characterization of Mo/Al2O3 composites

Abstract

In order to improve the performance of molybdenum, the Mo/Al2O3 composites were prepared by using a hydrothermal method for the synthesis of the precursor powders and subsequent powder metallurgical processing. The morphologies of the composite powders and the microstructures and properties of the composites were investigated. Compared with the pure Mo powder, the grains of composite powders are smaller because of the existence of the fine Al2O3 particles. The results from the sintered composites show that the fine Al2O3 particles are evenly distributed in the Mo matrix and well bonded with the Mo matrix. With increasing Al2O3 content, all the values of the micro-hardness, compressive strength and flow stress at 0.08 strain are increased. The strengthening effect is more remarkable at elevated temperatures. At room temperature, the compressive strength and the flow stress at 0.08 strain of the composite with 40vol.% Al2O3 are 1.67 and 2.01 times greater than those of pure molybdenum, respectively, while the values are up to 2.02 and 2.52 at 1100°C.