The process of vacuum brazing includes preparation, assembly, filling of solder, and application of flow inhibitor (if necessary) before brazing the parts. Brazing, vacuum brazing furnace discharge inspection. According to the structural condition of the components, the filling of solder can also be carried out before assembly.
Preparation before welding of parts:
The preparation before welding in a vacuum brazing furnace includes removing the oxide skin on the surface of the parts and removing oil and cleaning. Parts with mechanically processed surfaces that are free of oxide skin only need to undergo a degreasing and cleaning process. Special components require some special processing
1. Deoxygenated skin
Mechanical cleaning method, using a knife, sandcloth, metal grease or grinding wheel to polish the surface to be welded. Sand blasting and shot blasting can also be used to remove oxide skin.
2. Physical cleaning method: Ultrasonic cleaning is a method of physically removing oxide films. Its principle is to rely on the cavitation effect generated inside the liquid by ultrasonic propagation in the liquid medium to remove the oxide film on the metal surface. For stainless steel or high-temperature platform metal components, the commonly used medium solutions are propane fan, alcohol, triazine, gasoline, or steam filling water. The frequency of the ultrasonic field is 20000 Hertz, and the cleaning time generally does not exceed 30 minutes.
During ultrasonic cleaning, the parts should not be overlapped, and the cleaned parts should be immersed in a medium solution to ensure that dirt is easy to flow out.