Surface characterization of CVD tungsten coating on molybdenum substrate

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2-μm-thick diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows that tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad effects to the adhesion. The result of high-temperature diffusion experiment in the diffusion rate from molybdenum substrate to tungsten coating is faster.