High-Temperature Brazing Powder
Brazing powder for high-temperature applications is a fine-grained flux powder based on borides or fluorides that dissolves oxides on the joint faces during brazing and promotes the capillary action of the filler metal.
Physical-Chemical Mechanism of Action
Brazing flux for high-temperature applications consists of fine particles of borides or fluorides. These particles react with oxides on the joint surface and dissolve them, freeing the surface and improving the capillary action of the molten brazing filler metal.
Metallurgical Relevance & Welding Risks
Without flux, oxides on the joint surface can prevent brazing or impair the quality of the joint. The flux ensures that the filler metal stays liquid and spreads evenly across the entire joint, guaranteeing a clean and tight bond.
Workshop Practice & Action Guidelines
Use flux at a concentration of 1-2 % of the total weight of the filler metal. Make sure the powder is spread finely and evenly over the joint. Set the temperature so that the filler metal stays liquid but doesn't evaporate too quickly. At high temperatures, the flux can react faster and achieve a better joint.