Preparation And Properties Of CrAlN Composite Coating

At present,our hard coating industry has entered the industrialization,but there are still many problems in the actual production.At present,there are some problems such as poor uniformity,poor coating surface quality,poor bonding strength and slow deposition rate.The addition of Al element in CrAlN coating improves the performance of all aspects of this kind of coating.There are few studies on changing the transition layer,adding Si and Ti elements to the transition layer to improve the hardness,bonding strength and machining performance of the coating,and there are few articles on systematically exploring the influence of arc ion plating process parameters on the structure and performance of CrAlN coating.In this paper,Cr/CrN/CrAlN coatings and TiN/TiSiN/CrAlN coatings were prepared by arc ion plating and deposited on YT15 cemented carbide blades to explore the effects of process parameters on the structural morphology and properties of the two coatings.The optimum technological parameters of Cr/CrN/CrAlN coating and TiN/TiSiN/CrAlN coating were proposed,which provided theoretical support for future production.The oxidation and machinability of two CrAlN coatings with different transition layers were compared.The specific content includes the following aspects:(1)Cr/CrN/CrAlN coatings prepared by arc ion plating were deposited on YT15 cemented carbide blades to explore the effects of different deposition temperature and arc current on the structure morphology and properties of coatings.The increase of deposition temperature and arc current will increase the energy of particles passing through the sheath to the substrate and enhance the bombardment effect.(2)The TiN/TiSiN/CrAlN coating was prepared and deposited on the YT15 cemented carbide blade by arc ion plating in physical vapor deposition,and the effects of matrix bias and nitrogen pressure on the microstructure and properties of the coating were investigated.The increase of matrix bias will make the particles get more energy,and the bombardment effect will be enhanced.The increase of nitrogen pressure will make the metal particles react fully with nitrogen,and promote the reduction of large particles on the coating surface.However,the matrix bias should not be too high,and the strong anti-sputtering effect will reduce the coating thickness.(3)Cr/CrN/CrAlN and TiN/TiSiN/CrAlN coatings were prepared by the optimum technology,and the structural morphology,mechanical properties,high-temperature oxidation properties and machinability of different transition layers were compared.