Abstract: The two Ti-Al-Zr targets and one pure Cr target were used to prepare the TiAlZrCr/(Ti, Al, Zr, Cr)N gradient films on high speed steel (W18Cr4V) substrates by multi-arc ion plating technique. Short-term isothermal (at 600℃, 700℃, 800℃ and 900℃ for 4h) and long-term cyclic (at 700℃ and 800℃ for 100h) high temperature oxidation behavior of the gradient films were studied. Then the oxide scales formed on the film specimens were characterized by scanning electron microscopy (SEM), energy dispersion X-ray spectroscopy (EDS) and X-ray diffraction (XRD). It was showed that, under short-term isothermal condition, the high temperature oxidation resistance of the gradient film was excellent up to 800℃ and an oxide scale comprising TiO₂ was observed. On the other hand, under long-term cyclic high temperature condition, the oxidation resistance of the gradient film was excellent at about 700℃.

Key words: Multi-arc ion plating, TiAlZrCr/(Ti, Al, Zr, Cr)N gradient film, High speed steel, High temperature oxidation resistance