What does silver brazing flux remove from the surface before brazing?

Silver brazing flux plays a critical role in the brazing process by preparing the surfaces to be joined. The primary function of the flux is to remove oxides from the surface of the metals being joined. When metals are heated, especially at the high temperatures required for brazing, they can form oxides that create a barrier, preventing proper adhesion and the flow of the filler material.

By effectively removing these oxides, the brazing flux ensures that a clean and reactive surface is presented, which promotes better wetting of the filler metal. This not only improves the strength and integrity of the joint but also aids in achieving a smooth and uniform flow of the brazing material. Without the removal of oxides, the filler metal would struggle to bond effectively, leading to weak joints or complete failure.

While contaminants, moisture, and air can also have negative effects on the brazing process, the specific role of silver brazing flux is predominantly focused on handling oxides to facilitate optimal bonding.