Microstructure and Properties of TiAlN Films Prepared by Mid-frequency Non-equilibrium Magnetron Sputtering

(Ti_1-xAl_x)N films were prepared on YG10-cemented tungsten carbide surface by using mid-frequency non-equilibrium magnetron sputtering. The films' properties were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), and microhardness and surface property testing. Effects of nitrogen partial pressure, DC bias voltage, and Al content on the mechanical properties, composition, and microstructure of the films were investigated. The films were composed of (Ti, Al)N columnar crystals. The concentration of nitrogen in the film increased with the increasing of nitrogen partial pressure, while the concentrations of Al and Ti, the atom ratios r_Al/(Al+Ti) and r_(Al+Ti)/N were decreased. The (111) crystal orientation became less prominent, and the (220)and (200)orientations became predominant. Mechanical testing show that, with the increasing of Al concentration and DC bias voltage, the film hardness and thickness, along with the binding force between the film and substrate, all initially increase and then decrease. The maximum microhardness of the films is 2915 HV, and the maximum binding force between the film and substrate is 73 N.