The pvd coating machine uses arc ion plating method for brass plating bright chromium or nickel watch case plating TiCN film.
        pvd coating machine adopts small arc source coating machine and pulse bias power supply;
        (1) Workpiece cleaning, rack loading, and furnace loading. The workpiece must go through three processes of ultrasonic cleaning, pickling and rinsing before entering the furnace.
        The first is to put the metal cleaning agent prepared according to the usage requirements in the ultrasonic cleaning tank, and use the ultrasonic for degreasing and cleaning. After cleaning, pickling is carried out, which can neutralize the residual lye during ultrasonic cleaning and can also act as an activation treatment. Then perform rinsing to completely remove the acid solution. Deionized pure water or distilled water must be used for rinsing. After three washings, it is dried immediately. The temperature is generally controlled at about 100°C and the time is about 1 hour. It can also be put into the stove immediately after air drying.
       (2) Preparation work before coating of vacuum coating machine
        ①Clean the coating room of the pvd coating machine. Clean the coating room of the pvd coating machine with a vacuum cleaner. After multiple coatings, the lining board of the pvd coating chamber needs to be cleaned regularly, usually once every half a month.
        ②Check the arc evaporation source. Before work, make sure that the arc evaporation source of the vacuum coating machine is installed correctly, the insulation is good, the arc ignition needle is controlled flexibly, the process is appropriate, and it can just touch the cathode surface.
        ③Check the insulation of the workpiece holder. The insulation between the workpiece holder and the ground of the vacuum coating machine must be good, and the contact point between the negative bias power supply and the workpiece holder must be in good contact.

        After the above several tasks have ensured that there is no problem, the door of the coating chamber of the vacuum coating equipment can be closed for air extraction and coating.

Coating
        ①Titanium plating Vacuum degree: high-purity argon gas is passed through, and the vacuum degree is maintained at 2 x 10-2Pa. Pulse bias: 200～300V, duty cycle 50%. Arc current: 60～80A, ignition of all arc sources, time 2～3min.
        ②TiCN plating vacuum degree: pass high purity nitrogen to keep the vacuum degree at (3～8) x 10-1Pa, and then gradually increase the C2H2 gas. As the amount of C2H2 gas increases, the color changes from golden to red to golden to rose Gold to black changes. Control the ratio of N2 and C2 H2 to achieve a predetermined chromaticity.
        Arc current: 50～70A. Pulse bias: 100～150V, duty ratio 60%～80%. Deposition temperature: about 200℃. Time: 10-20min, film thickness 0.2-0.5μm.
        Cooling After the coating process of the pvd coating machine is completed, first turn off the arc power supply and the bias power supply, and then turn off the air source and stop the rotating rack. When the workpiece is cooled to 80-100°C in the coating chamber of the vacuum coating equipment, the coating chamber of the pvd coating machine is filled with air, and the workpiece is taken out.