Influence of powder ball milling pretreatment on microstructure and properties of Mo-W-Cu refractory functional alloys sintered in a normal-pressure hydrogen atmosphere

Abstract

In this work, the effect of powder ball milling pretreatment on the microstructure and properties of the Mo-30W-20Cu (mass fraction) refractory functional alloys sintered in normal-pressure H2 is investigated systematically. The results indicate that a moderate milling can obviously refine the particle size of the Mo-30W-20Cu composite powder, largely contributing to the sintering densification and thermo-physical property improvement. In contrast, an excess milling instead causes reaggregation of plastic Cu particles, negatively influencing the following compact densification and the property improvement. The composition analysis shows that there is a strong compositional inheritance correlation between the pretreated powders and the corresponding bulk alloys. Besides, the experimental and the calculated results of the thermal and electrical conductivities of the sintered alloys are compared, and they show a similar trend with milling time varying. This work can provide valuable theoretical and technological insights for preparation of high-performance Mo-W-Cu refractory functional alloys.