Chemical Vapour Deposition of TiC and TiC_xN_y on the Cemented Carbide

The deposition ratd and microhardnoss of the coating ofTiC and TiC_xN_y increase with input molar ratio (m_c/Ti) and the maximum microhardness of TiC and TiC_xN_y are achieved as the ratio is 1 and 0.87 respectively. The coalings identified by X-ray di ff ractometer is TiC and TiC_xN_y. When m=0.94-1.47. deposition temperature at 1 223-1 323 K. the η phase at interlayer between the substrate and TiC coaling is not formed; m_c/Ti=0.68-1.54. at 1 248K, N₂/H₂=1/2. the coating only is TiC_xN_y; m_c/Ti ≤ 0.28. the η phase is formed. The apparent activation energy of TiC is 157.9 kJ/mol. It proves that the deposition process is controlled by surface process.