Transmission electron microscopy studies of growth and interface structure of chemically vapour deposited TiC and TiN films on WCCo alloy subsrates

Abstract

It is known that the interface structures between deposits and substrates and the growth microstructure of deposits are important factors in the wear resistance of coating films. TiN and TiC films prepared by the chemical vapour deposition (CVD) method on WCCo alloy substrates were investigated using transmission electron microscopy (TEM). The thin foil for TEM was prepared using cross-sectional techniques. CVD TiC and TiN seem to be directly bonded with WCCo alloy and η phase without any pores at the interface. Deposits were fine grained at the initial stage of deposition. As the thickness of a film increased, the grains of CVD TiN became elongated in the direction of the growth with a preferred 220 orientation. High resolution TEM revealed that the grains in CVD TiC were connected with each other without any second phases.