THIN TICX FILMS CHEMICALLY VAPOR-DEPOSITED ONTO CEMENTED CARBIDES FROM THE TICL4-CCL4-H-2 MIXTURE

Results on the study of the deposition rate, structure, composition an d some properties of TiCx films deposited from the TiCl4-CCl4H2 gaseou s mixture when varying the CCl4/TiCl4 mole ratio are presented. The cr ystal lattice parameter of the films slightly increases when increasin g the CCl4/TiCl4 ratio from 0.3 to 0.8. The average grain size of the TiCx films significantly decreases and their microhardness correspondi ngly increases when decreasing the CCl4/TiCl4 ratio from 0.5 to 0.1. T he deposition rate has a maximum at the CCl4/TiCl4 ratio value of arou nd 0.4. Due to enhanced reactivity of CCl4 compared with that of metha ne utilized as a carbon source in the CVD of TiCx films, it is possibl e to completely eliminate formation of a decarburized eta-phase underl ayer in the cemented carbide substrate when depositing from the TiCl4- CCl4-H-2 mixture. The TiCx films when applied as wear-resistant coatin gs for cemented carbide tools allow improvement in tool lifetime compa rable with that of conventional TiCx coatings chemically vapour deposi ted from the TiCl4-CH4-H-2 mixture.