Flux

The flux basically fulfills a threefold task during soldering: it wets the surface of the base metal to make it more moist, protects the filler alloy and the base metal from oxidation during melting and serves as a temperature indicator. The fluxes are based on active salts. They are administered in the form of paste, powder or liquid. To be effective, the flux must have a lower melting point than the solder, be in a liquid state at the soldering temperature and remain active throughout the soldering process. After soldering, the flux residues must be easy to remove and must not be aggressive and cause corrosion.
In flux soldering, two metal parts are joined together using a solder and a flux. The flux helps to clean the metal surfaces and prevent oxidation, which can weaken the joint.

Flux soldering is an important process in the world of soldering that aims to improve the quality and reliability of soldered joints. A flux, a chemical compound, is applied to the surfaces to be soldered. The flux serves several purposes in soldering, including:

Cleaning: The flux helps to remove oxides, dirt and contaminants from the surfaces to be soldered. This cleaning action ensures better wetting and bonding of the solder to the materials, resulting in stronger and more reliable solder joints.

Oxidation protection: Fluxes form a protective barrier that prevents oxidation of the solder and the surfaces to be soldered. Oxidation can weaken the solder joint and lead to poor electrical conductivity, so the flux acts as a protective shield to maintain the integrity of the joint.

Surface tension reduction: The flux reduces the surface tension of the molten solder, allowing it to flow more easily and evenly over the solder joint. This facilitates the formation of smooth, even solder joints without voids or irregularities.

There are many different types of solder. The most common fluxes are silver solder (which has a high melting point and is corrosion resistant and is made from a mixture of silver, copper and other metals) and copper solder (which has a low melting point and is easy to work with).

Flux solder is versatile (flux solder can be used to join a variety of metals together) and offers strength, durability, cost effectiveness and can withstand a variety of environmental conditions.

Factors to consider when selecting flux solders include the soldering application, the materials to be joined and any special requirements or regulations. It is important to select the correct solder diameter and alloy composition to ensure compatibility with the soldering task.

As with any soldering process, it is important to follow proper safety practices, including working in a well-ventilated area, using appropriate soldering equipment and wearing protective clothing when necessary.

Fluxes provide a convenient and reliable solution for soldering as the flux is incorporated directly into the solder alloy. This simplifies the soldering process, improves the solder flow and helps to achieve high quality solder joints in various applications.