Study On Preparation And Properties Of TiAlN?CrAlN Coatings By Arc Ion Plating

The hard coatings require better properties with the advance of modern industrial technology,they should not only have smooth surface,but also have good mechanical properties.Arc ion plating is widely used in hard coatings because of its many advantages such as high ionization,high deposition rate and strong adhesion.The macroparticle contamination is the most serious problem that inhibits further applications of arc ion plating.TiAlN coatings were deposited on M2 high speed steel at various deposition temperatures,substrate bias voltages,arc currents and coil voltages by magnetic enhanced arc ion plating technique.CrAIN coatings were deposited on M2 high speed steel at various deposition temperatures,arc currents of cylindrical target,substrate bias voltages and nitrogen pressures by magnetic enhanced arc ion plating technique.The relationships between deposition parameters and coating properties were investigated.The magnetic enhancement device could change the morphology and the movement of the cathode spots.Due to the application of magnetic enhancement and etching cleaning technology,the surface macroparticles decreased obviously compared with the conventional arc ion plating.Increase of the deposition temperature,bias voltage,arc current and coil voltage could improve the compactness of the coatings,and the coatings became denser.The crystalline phases were face centered cubic TiN and close-packed hexagonal AIN,and the coatings exhibit(200)preferred orientation.The thickness of the coatings were in the range of 2?4 ?m.With increasing the deposition temperature,substrate bias voltage and arc current,the hardness first increased,and then decreased again.The hardness increased gradually with the increase of coil voltage.In this paper,the TiAlN coating had a maxmum hardness of 3741 HV.The trend of adhesion strength was in accordance with the relationship between the hardness of coating and the deposition parameter,and the TiAlN coating had a maxmum adhesive strength of 36.3 N.The crystalline phase was face centered cubic CrAlN of the CrAlN coatings,and the coatings had a thickness of about 2?4 ?m,had dense and fine surface morphology under high deposition temperature,arc current of cylindrical target,bias voltage and nitrogen pressure.The size and depth of micro-craters in the coating increased as the deposition temperature and the bias voltage reached a certain value.With increasing the deposition temperature and bias voltage,the hardness first increased,and then decreased again.The hardness increased gradually with the increase of arc current of cylindrical target and nitrogen pressure.In this paper,the CrAlN coating possessed a maxmum hardness of 3701 HV.The adhesion strength first increased,and then decreased again with increasing the deposition temperature and bias voltage.With increasing the arc current of cylindrical target and nitrogen pressure,the adhesion strength increased gradually,and the CrAlN coating had a maxmum adhesive strength of 37.9 N.