Fabrication of an ultrafine-grained W-ZrC-Re alloy with high thermal stability

Abstract A bulk ultrafine-grained (UFG) W-ZrC-Re alloy is fabricated via a developed bottom-up powder metallurgy process. The detailed fabrication processes including the mechanical alloying and spark plasma sintering have been introduced. The relative density of this UFG W-ZrC-Re is as high as 99.5 %, and the average grain size is about 0.4 μm and uniform dispersion particles with the average particle size of ∼28 nm and number density of 1.48 × 1021 /m3. The W-ZrC-Re exhibits high thermal stability that maintains its UFG microstructures as well as a high hardness (∼740 HV) even after annealing at 1500 °C for 1 h. This high thermal stability is attributed to the synergistic effects of the nano-sized ZrC particle pinning and Re solute drag, which demonstrates a good potential in the manufacturing of high-stabled UFG and even nanocrystalline W materials.