Diffusion processes in tungsten metal, alloys, thin films and foils

Abstract

Volume, grain boundary and surface diffusion processes in W metal and alloys have been reviewed and data compiled. The relative diffusion kinetics of the three processes have been characterized and reveal that the volume diffusion is the slowest mode of atomic transport followed by grain boundary and surface diffusion. New data on 67Cu radiotracer diffusion in chemical vapor deposited W films and sintered foils are presented and the interplay of volume and grain boundary diffusion is illustrated over a wide temperature range. At temperatures < 2000K of interest for powder metallurgical processing, chemical vapor deposition and sintering, short circuit diffusion is found to be the dominant mechanism.