flux

Flux is a substance that is used to help remove impurities from metals. It is often used in soldering, which is a process of joining two pieces of metal together using heat and a filler metal.

Flux helps to remove the oxides that form on the surface of the metal when it is heated. These oxides can prevent the solder from flowing properly, so it is important to remove them before soldering.

Flux is usually a liquid or paste, and it is applied to the surface of the metal before soldering. The flux melts and flows over the surface of the metal, carrying the oxides away.

Once the flux has melted, the solder is applied to the joint. The solder flows over the surface of the metal, bonding the two pieces together.

The solder flux helped the solder to flow smoothly.