Study On The Preparation And Properties Of Ti_1-xAl_xN Films Deposited By The Multi-Arc Techniques

The multi-arc plating process,as one method of the physical vapour deposition, it especially can be used to prepare metallic compound coatings or metal coatings with high melting point on metal surface, it has been onrushing developed since 1980's and become one of the most advanced technique at present.The main hard coating material for tools and dies is TiN. Preparation of TiN by kinds of techniques have been studied in-depth and used in protection of tools. However, TiN film tend to oxidize at temperature above 550℃and easily become invalidate if being used in particular environment. It was find that adding other element like Cr,Al,Zr,C,Si and so on or multi-coatings such as TiN/Ti,TiN/VN,TiN/CrN could improve coating property. So most study on TiN based coatings basically were concentrated on these two directions.TiAlN is a very promising material for wear resistant coatings because of its excellent high temperature corrosion and oxidation resistance which results in higher hardness and wear resistance, in comparison to TiN. In this paper, TiAlN coatings were deposited by multi arc evaporation on W18Cr4V high-speed steel. Furthermore properties of TiAlN layers were also studied preliminarily.The deposition parameters such as gas pressure, target power,bias voltage and deposition temperature were changed to study their affections on coating properties, The coating properties such as hardness, phase structure, chemical location, microparticle and oxidation action were discussed and tested. The chemical component, microstructure(phase structure, preferred orientation, compaction ,etc),and oxidation behavior of different coatings were also examined.It suggested that increasing deposition times about 60minutes and deposition temperature at 550℃(for high speed steel); gas pressure is 1Pa; Ti target power choose as 80A and Al as 70A and bias voltage is 100V. (Ti,Al)N films will gain superior properties.Besides (Ti,Al)N phase, it contains a number of (Ti2,Al)N phase using the process mentioned above. All (Ti,Al)N phase grow along (111) crystal face by preferred orientation, no matter how much Al it contains. The property of Ti1-xAlxN coatings, such as hardness, bonding force and wearing resistance, will increase by the augment of Al content. But it will reduce when it contains too much Al. There are many factors for this change, such as misconstruction on crystal, preferred orientation and lattice distortion, which is because of content of Al. So there is the best content of Al for the finest property. Experiments results show that it performs the finest property when the coating contains 25% Al. For example, its hardness achieve...