Copper-Phosphorus Brazing Self-Fluxing
Phosphorus-alloyed copper solder flows even when joining copper materials because phosphorus reduces surface oxides and thus promotes fluidity.
Physikalisch-chemischer Wirkmechanismus
Phosphorus-alloyed copper contains phosphorus, which acts as a reducing agent for surface oxides. This reduces the oxides on the surface of the material being brazed, promoting the flow of the filler metal.
Metallurgical Relevance & Risks in Welding
The self-fluxing nature of copper-phosphorus brazing filler metal reduces the need for additional flux, making the joint easier. However, too much phosphorus can alter the metal's structure and impair its strength. It is important to use the right phosphorus content.
Workshop Practice & Instructions
Use copper-phosphorus self-fluxing brazing filler metal when joining copper materials to save on additional flux. Make sure the phosphorus content in the filler metal is between 0.5% and 1%. This ensures good self-fluxing without loss of strength.