Synthesis and thermal stability of Al75W25 alloy obtained by mechanically alloying

Al75W25 nanocrystalline alloy is synthesized by mechanically alloying the pure metal powder mixtures. The decrease of fcc Al peaks from XRD patterns as a function of milling time suggests the formation of an extended W(Al) solid solution, even though no significant change of the bcc lattice parameter is observed. The supersaturated solid solution is stable at 700 °C in vacuum, and the formation of Al4W intermetallic compound occurs when the MA-ed powders are annealed at 900 °C. After TG analysis, we find that the oxidation resistance of Al75W25 alloy is much improved compared with metal W, may be due to the passivity of Al.