Optimization of Surface Quality of CrAlN Coatings Fabricated Using Cathode Multi-Arc Ion Plating

To solve the wear problem of stamping dies in high-speed machining，cathodic multi-arc ion plating is often used to improve surface properties，and the surface quality of cathode multi-arc ion plated coating is one of main factors affecting the life of stamping dies.In this paper，the effects of the DC bias voltage，flow rate of nitrogen and arc current on the surface quality of CrAlN coating were studied by the orthogonal experiments.The significance of the effects of DC bias voltage，flow rate of nitrogen and arc current on the surface quality of the CrAlN coating was analyzed by the extreme-range method and variance method.Results showed that the surface quality of the CrAlN coating was affected most significantly by the flow rate of nitrogen，and the DC bias voltage also influenced the number of large particles on the surface of the CrAlN coating.When the DC bias voltage was 160 V，the nitrogen flow rate was 1 600 mL/min，and the arc source current was 120 A，the as-prepared coating possessed the minimum number of large particles on the surface (42.5 per 10，000 μm2) and the optimal surface quality.