Consolidation behavior of Mo30W alloy using spark plasma sintering

Molybdenum alloys are excellent candidates for extremely high temperature environments, such as in nuclear thermal propulsion spaceflight systems. Spark plasma sintering is a useful manufacturing technique that allows rapid fabrication of refractory materials difficult to sinter using more traditional methods. Pre-alloyed molybdenum with 30 wt% tungsten powder was consolidated spark under variety conditions determine the optimum conditions. Hold temperatures between 1400 and 1700 °C, at pressures from 10 50 MPa, hold times maximum 0.5 90 min were tested. The effects temperature, pressure, time on microstructure mechanical properties examined. Higher applied necessary achieve higher sample density lower temperatures. Sintered densities ranging 88.8 97.9% theoretical achieved over testing conditions, highest being °C MPa 5 min. hardness sintered material followed Hall-Petch inverse grain size relationship investigated sizes. Grain growth 1600 found follow second order time. When compared pure molybdenum, solid solution strengthening observed increase alloy. From these experiments analysis, an understanding how affect alloy developed will allow future development ceramic metallic composite propulsion.