Induction Brazing Basics for jointing copper,silver,brazing,steel and stainless steel,etc.
Induction Brazing uses heat and filler metal to join metals.ย Once melted, the filler flows between close-fittingย base metals (the pieces being joined) by capillaryย action. The molten filler interacts with a thin layerย of the base metal to form a strong, leak-proof joint.ย Different heat sources can be used for brazing:ย induction and resistance heaters, ovens, furnaces,ย torches, etc. There are three common brazingย methods: capillary, notch and moulding. Inductionย brazing is concerned solely with the first of these.ย Having the correct gap between the base metals isย crucial. A too-large gap can minimize the capillaryย force and lead to weak joints and porosity. Thermalย expansion means gaps have to be calculated forย metalsย at brazing, not room, temperatures. Optimumย spacing is typically 0.05 mm โ 0.1 mm.ย Before you brazeย Brazing is hassle-free. But some questions shouldย be investigated โ and answered โ in order to assureย successful, cost-effective joining. For instance: Howย suitable are the base metals for brazing; whatโsย the best coil design for specific time and quality demands;ย should the brazing be manual or automatic?
Atย DAWEI Induction we answer these and otherย key points before suggesting a brazing solution.ย Focus on fluxย Base metals must usually be coated with a solventย known as flux before they are brazed. Flux cleansย the base metals, prevents new oxidation, and wetsย the brazing area prior to brazing. It is crucial to applyย sufficient flux; too little and the flux may become
saturated with oxides and lose its ability to protectย the base metals.ย Flux is not always needed. Phosphorous-bearing filler
can be used to braze copper alloys, brass and bronze.ย Flux-free brazing is also possible with active atmospheresย and vacuums, but the brazing must then beย performed in a controlled atmosphere chamber.ย Flux must normally be removed from the part onceย the metal filler has solidified. Different removalย methods are used, the most common being waterย quenching, pickling and wire brushing.