The formation of tungsten and tungsten carbides by CVD synthesis and the proposed mechanism of chemical transformations and crystallization processes

Tungsten (α-W and β-W modifications) and various tungsten carbides (W2C, WC1−x, WC) coatings were formed by chemical vapor deposition (CVD) in WF6, C3H8, H2 gas reactions. The structure of reaction products was studied by transmission electron microscopy and X-ray diffraction. The microhardness of coatings was determined by Vickers method. The mechanism of the CVD process is proposed to explain the formation of W or various (W-C) coatings and the variety of grain sizes in corresponding deposits.