| Ti N film is widely used in mechanical, aerospace and other fields due to their high hardness, high wear resistance and golden color in the last decades. However, the lower toughness limits the possible applications of Ti N films. Therefore,the films which have excellent comprehensive mechanical properties should be developed to meet the actual requirements. Recently nanocomposite films have been paid much attention due to their excellent comprehensive application performance.In this paper, Ni-Ti N nanocomposite films were deposited under different flow rate of N2, power of Ni target, substrate temperature and negative bias voltage by reactive co-sputtering. The microstructures of the as-deposited films were examined by X-ray diffraction, scanning electron microscopy and atomic force microscopy; Hardness and elastic modulus of the as-deposited films were determined by nanoindenter. Corrosion resistance of the films was studied by electrochemical test system and the film/substrate adhesion force was investigated by multi-function test instruments for surface properties of material.The influence of the flow rate of N2 on microstructures and properties of Ni-Ti N nanocomposite films was investigated. The results show that Ti N crystallite sizes and depositing rate of the films decreased with the increase flow rate of N2. The root mean square roughness(RMS) first decreased and then increased. When the N2 flow rate was 16 m L/min, the RMS of the films reached minimum value of 2.75 nm. At this time, the film/substrate adhesion force reached the maximum value of 28 N.The effect of the power of Ni target on Ni-Ti N nanocomposite films was studied. It found that the size of the grains was larger and the preferred orientation of the films was Ti N(111) plane at lower power of Ni target. When the power of Ni target increased the preferred orientation changed from Ti N(111) to(200) plane and the grain size gradually decreased and the grains were apparently refined. The film deposited at power of Ni target of 35 W was smoothest, and its RMS was 3.14 nm. Meantime, the film/substrate adhesion force and the corrosion resistance were best. When power of Ni target was increased from 25 W to 45 W, the hardness and elastic modulus increased from 15.1GPa and 288 GPa to 21.1 GPa and 290.5 GPa, respectively, and the resistance to plastic deformation(H3/E2) was best. However, hardness and elastic modulus decreased to 18.2 GPa and 281.4 GPa when power of Ni target was further increased to 55 W.The experimental results of the effect of the temperature on the films show when the temperature was increased from 100°C to 400°C, the preferred orientation of films was changed from Ti N(111) to(200) plane. The average grain size of the Ti N crystallites in the films firstly decreased and then increased. And film/substrate adhesion force and the corrosion resistance of the films first increased and then decreased. When the temperature was 200 °C, the average size of the Ti N grains reached minimum value of 12.5 nm and the RMS were smallest. When the temperature was 300°C film/substrate adhesion force and the corrosion resistance of the films was the best.The effect of the bias voltage on the films was the same as the temperature. With increasing bias voltage, the preferred orientation of the films was changed from Ti N(111) to(200) plane, and the average size of the Ti N grains firstly decreased and then increased, while the mechanical properties and corrosion resistance firstly increased and then decreased. When the bias voltage was-80 V, the average size of the Ti N grains reached minimum value of 13.6 nm, hardness and elastic modulus reached the maximum value of 19.2 GPa and 311 GPa, respectively, and the film/substrate adhesion force reached maximum value of 41 N, and the corrosion resistance was best. When the bias voltage was-120 V, the minimum value of RMS was 3.15 nm.By comparative experiments, the corrosion resistance of the Ni-Ti N nanocomposite films was much better than that of 304 stainless steel. |
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