Preparation And Performance Characterization Of Titanium Aluminium Nitride Thin Films Using PVD Technology

Superhard (Ti,Al)N thin films were prepared on W6Mo5Cr4V2high-speed steel substrate by multi-arc ion plating technology which is in hollow cathode electron beam assisted deposition situation,and the compound coating equipment of hollow cathode and multi-arc ion plating was used in this experiment.The formation mechanism of (Ti,Al)N thin film prepared by this technology were studied, and we discussed the effect of pulse bias voltage mode on micro-structure and mechanical property of thin films deposited by this workmanship. The phase composition, microstructure and the element of the thin film were characterized respectively with X-ray,scanning electron microscopy and EDAX. It were tested that the hardness of the thin film, film/substrate bond strength, resistance to friction performance and3D profilemeter by universal nano/micro material tester.The results show that the auxiliary function of hollow cathode electron beam can increased ionization ratio of depositional grain, restrained macro-particles contaminate on surface of film, and the (Ti, Al)N thin films deposited by this technology more compact and smooth compared with the thin film prepared with multi-arc ion plating technology. Hollow cathode electron beam can form plasma electron beam zone which contain a good deal of high energy and high density grain, and they can reduce the quantity and size of macro-particles.The plasma of high energy and high density can also enhance activation radioactivation to the surface of the substrate and promote the formation of tiny crystalline grain,thus improved the compactness and reduced the surface roughness of the film,and enhanced the mechanical property and resistance to friction performance of the thin film.Pulse bias voltage value and duty cycle have a great impact on micro-structure and mechanical property of (Ti,Al)N thin films. with the increase of pulse bias voltage value,the quantity of macro-particles on the surface of the film and the surface roughness gradually reduced,and the surface of the thin film gradually become smooth.The nanohardness and film/substrate bond strength of (Ti,Al)N thin films increased with the enchantment of pulse bias voltage value, and the nanohardness and film/substrate bond strength reached respectively40.6GPa and65N when the bias voltage value is-400V,but when the bias voltage value greater than-400V the hardness and film/substrate bond strength will be decrease because of high temperature rise effect.Duty cycle don’t have obviously inhibitory action to macro-particles,but it have a great impact on compactness of (Ti,Al)N thin films.The thin film have plenty of holes when the duty cycle is20%,and the hardness value is less than20GPa.When the duty cycle reached80%the hardness is38.2GPa,and the thin film is great compact,at the same time,enhanced the resistance to friction performance of (Ti,Al)N thin films.