Microstructure and properties of TiCrN coatings by arc ion plating

TiCrN coatings were deposited onto high-speed steel substrates by arc ion plating. The crystalline structure of the coatings was analysed by X-ray diffraction. Influence of both negative bias applied to the substrates and nitrogen flowrate on the crystalline structure was investigated. Scanning electron microscopy was employed to observe the surface quality of the coatings. Hardness of the coatings was measured by the XP nanoindenter. It is indicated that both size and quantity of the macroparticles decrease with increasing negative bias. TiCrN coatings with enhanced hardness can be obtained when a larger negative bias is applied. Increasing nitrogen flowrate benefits hardness of the coatings as well. Compared with the TiN thin film, the TiCrN coatings exhibit better mechanical behaviour due to the solid solution strengthening effects caused by the doped Cr atoms. Influence of deposition parameters on the structure and mechanical properties has been discussed.