Preparation of hard film on 7A04 aluminium alloy by magnetron sputtering

Titanium nitride thin films were prepared on 7A04 aluminium alloy by unbalanced magnetic field magnetron sputtering. The phase composition of the films was analyzed by X-ray diffraction (XRD), and the surface morphology of the films was observed by scanning electron microscopy (SEM). The hardness and film-base bonding force of each sample under different sputtering process and time were analyzed by HVS-10 digital display Vickers hardness tester. The effect of sputtering time and process on corrosion resistance of 7A04 aluminium alloy was discussed by electrochemical polarization curve, and its corrosion behavior was analyzed.The experimental results show that TiN thin films with uniform and compact surface can be prepared on aluminium alloy by magnetron sputtering. The hardness of the coating is higher than that of the aluminum alloy substrate. The test of bonding force shows that the film-substrate bonding force is better than that of the film sputtered for 6 hours after 2 hours and 4 hours. A new phase Ti2N is formed by X-ray diffraction (XRD), which improves the hardness of the film. The electrochemical polarization curves show that the corrosion resistance of the film after coating is better than that of the aluminum alloy. The best corrosion resistance is the sample sputtered for 4 hours after heat treatment, which has higher corrosion resistance than the film treated by other processes.