Preparation, microstructure and mechanical properties of a Ce-PSZ reinforced molybdenum alloy

Improving the poor plasticity and fracture toughness of molybdenum alloys is the key to expanding their industrial applications. In this experiment, a cerium partially stabilized zirconia (Ce-PSZ) reinforced molybdenum alloy with outstanding properties was obtained by combining the hydrothermal method and the powder metallurgy technology. This study investigated how varying Ce-PSZ content influences the microstructure and mechanical properties of Mo/Ce-PSZ alloys. The results show that with increasing Ce-PSZ addition, the relative density and hardness of the alloys gradually increase, while the tensile strength, plasticity, and fracture toughness exhibit a tendency to initially increase and subsequently decrease. When 1.5 wt% of Ce-PSZ is added, the Mo alloys achieve excellent overall mechanical properties, with an ultimate tensile strength of 528.5 MPa, elongation of 29.3 %, and fracture toughness of 38.5 MPa∙m 1/2 . These values are about 22.7 %, 22.5 %, and 83.3 % higher than those of pure molybdenum. The substantial enhancement in elongation and fracture toughness can be predominantly ascribed to the refinement of grains and the stress-induced Ce-PSZ phase transformation. This research provides a novel method for the preparation of molybdenum alloys with high fracture toughness and elongation.