Effect of Ti and Zr on high temperature mechanical and thermal properties of MoCu composites

Abstract

Based on the design concept of diversified alloys, the reinforcement of TZM alloys was combined in the fabrication of MoCu composites. The MoCu composites were prepared by vacuum hot press sintering under the effect of Ti, Zr elements added separately or simultaneously, and the microstructure adjustment was realized by mechanical ball milling on the pretreatment of the original alloy powder. The results show that Ti and Zr elements form metal-based solid solutions and intermetallic compounds by diffusion with Mo and Cu matrix during the sintering process. It can not only reduce the sintering activation energy of MoCu composites to improve the densification, but also improve the mechanical properties of the composites through certain solid solution strengthening and second phase strengthening. When Ti, Zr elements are added at the same time, Zr elements can enhance the β-stabilizing effect of Mo on Ti elements and improve the solid solution effect between Ti and Mo, Cu matrix, which further improves the interfacial bonding. Therefore, the 60Mo35Cu2.5Ti2.5Zr composites have the best overall performance, and their thermal properties and mechanical properties at room and high temperatures are greatly improved compared with the original 60Mo40Cu composites.