Deflection method inspection method of coating internal stress

The deflection method is generally used as a test method for the internal stress of the coating.

The test method is shown in Figure 11_7_3. Take a brass test piece with a size of 120mmx8mmx0.2mm. After heating to 700°C, anneal for 40 minutes, cool naturally, clean, dry, and flatten, and evenly coat one side of the test piece with paint. Insulation (the choice of insulating coating should vary according to the electrolytic value, pH and temperature), and then fix one end of the test piece in a plexiglass electrolytic chamber with a size of 250mm x 150mm x 12mm, and the other end is free and vertically downward. A corresponding anode is disposed at a distance of 150mm from the cathode of the test piece, and its size is 150mm x8mm x5mm. After the circuit is connected, the plating layer is deposited on the side of the test piece facing the anode. If there is internal stress in the plating layer, its free end will deflect. According to the deflection direction and magnitude of the free end, the direction and magnitude of the internal stress can be determined. (Related instruments: resistance meter, pH meter, Ion Meter)