Evolution of phase and mechanical high temperature properties of nano tungsten-5 wt. % molybdenum alloy by mechanical alloying and argon purged sintering

摘要

Nanostructured powders of tungsten (W) and molybdenum (Mo) with nominal composition of W_(95)Mo_5 (in wt. %) were synthesized by mechanical alloying (MA) followed by compaction at 1GPa pressure for 5 minutes and conventional sintering at 1500℃ for 2 h in argon atmosphere. The microstructure and evolution of phases during milling and consolidated products were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Minimum crystallite size of 44.4 nm and maximum lattice strain and dislocation density of 0.35% and 9.96 (1016/m~2) respectively was achieved in W_(95)Mo_5 alloy after 10 h of milling. W_(95)Mo_5 alloy showed sintered density, hardness, strength and elongation of 90.7%, 8.09 GPa, 0.74 GPa and 10.27% respectively, whereas minimum wear depth of 32.43 μm was achieved after 10 h of milling. Oxidation measurement was also carried out to investigate the high temperature behavior of W-Mo alloy system.