What is the primary purpose of using flux in the soldering process for copper or brass parts?

Using flux in the soldering process for copper or brass parts primarily serves to prevent oxidation. When metals like copper or brass are heated during soldering, they can develop oxidized surfaces that impede the bonding process. Oxidation occurs because the metal reacts with oxygen in the air, which can create a barrier that prevents solder from properly wetting the surfaces and forming a strong joint.

Flux acts as a cleaning agent, removing any existing oxidation and creating a protective layer on the metal surfaces during the soldering process. This ensures that the solder can adequately flow and adhere to the metal, allowing for a reliable and durable joint. By preventing oxidation, flux plays a crucial role in ensuring the effectiveness of the soldering process.

While joint strength, conductivity, and speed may be influenced by other factors in the soldering process, the specific purpose of flux is fundamentally about preventing oxidation to ensure proper adhesion of the solder to the metal components.