Diffusion mechanism of ion bombardment W-Mo surface alloying

The W-Mo alloy layers were obtained by double glow plasma surface alloying technique. The alloying results were compared between processing conditions: with or without ion bombardment on the surface of substrate. The binding energy of vacancy with the solute atoms of W and Mo was calculated. According to the energy condition of solute-vacancy complex diffusion, the mechanism of solute-vacancy diffusion played an important role in the double glow plasma surface alloying process. The results explained the high diffusion efficiency of W-Mo atoms in the alloying process and gave the precipitation of large quantity of intermetallics at grain boundaries during the cooling process after the alloying treatment.