I do automobile lighting fixtures, and the filament and lampshade are welded by DC tread type spot welding machine.The problem now is the welding of the molybdenum cover (in brief, it is to weld the two molybdenum alloy sheets together),It is easy to loose, cause bad products cover molybdenum off a bit more, ask the professionals should be how to solve this problem, reduce the probability of bad products.I hope you can make constructive suggestions.
1, foot type spot welding machine is a simple function, low price, poor control accuracy and stability of the old welding machine. Even when the workpiece parameters and electrode conditions are the same, the welding quality will be different due to the difference of the network voltage and self temperature.2, the electrode condition is normal.3. Can the consistency of the work itself be guaranteed?.4, welding machine specification selection, for welding your product is appropriate.5 、 whether the power supply system matches.
The selection of welding parameters is not suitable. Do the tests before each job? Because the stability of the welding machine is not good, the quality of the same parameter is different at different time. For resistance welding, tests must be performed before each work
1, adjust the welding parameters: welding current and voltage of different materials and different thickness of the welding speed is not the same, you are suggestions according to the welding materials to do a sample test, find a suitable welding parameters. After the test piece is finished, do the welding evaluation, the appearance defect and the fusion depth. The size of the fusion can be cut into specimens, and the size of the weld is determined by pickling. The solder joints are fused into the weldment.2. Preparation before welding: the weldment is made of aluminum and the surface of aluminum is covered with oxide film. The film must be cleaned before welding and cleaned or pickled with wire brush. Because the melting point of the oxide film is above 1000 degrees, and the melting point of the aluminum material is below 1000 degrees, the existence of the oxide film prevents the fusion of the solder joint and the base metal. The estimate is the main reason. After the oxide film is cleaned, it should be welded within 3 hours. Otherwise, the film will be re oxidized with air.
