What does flux aid in regarding molten filler metal?

Flux plays a crucial role in the brazing process by promoting the flow of molten filler metal. During brazing, flux is applied to the surface of the metals being joined and helps to remove any oxides and contaminants that could hinder the adhesion and flow of the filler metal. By creating a clean surface and reducing surface tension, flux enables the molten filler metal to spread more easily and uniformly across the joint. This improved flow is vital for ensuring a strong and effective bond between the materials being joined. Without sufficient flow, the filler metal may not adequately fill the joint, leading to weak connections or incomplete bonding.