There are many types of fluxes used for aluminum alloy smelting, which can be divided into two categories: covering agent and refining agent. The molten aluminum covering flux can prevent melt oxidation and gas absorption. Refining flux is used for degassing and removing inclusions.
Aluminum alloy flux is generally composed of alkali metal and alkaline earth metal chloride and fluoride, and its main components are KCL, NaCI, NaF, CaF, Na, AlF, Na, SiF, etc. The physical and chemical properties of the flux (melting point, density, viscosity, volatility, hygroscopicity, and interface effect with oxides, etc.) play a decisive role in the refining effect.
Chloride salt is the most common basic component in aluminum alloy flux, and the mixed salt of 45% NaCl + 55% KCI is the most widely used. Because they have a strong wetting ability to solid impurities and oxide films. At the melting temperature, the specific gravities of NaCI and KCI are only 1.55g/cm^3 and 1.50g/cm^3, which are significantly less than the specific gravity of aluminum melt. Therefore, it can be spread well on the surface of the aluminum melt, breaking and adsorbing the vaporized film on the surface of the melt.
However, fluxes only with chloride salts, the crushing and adsorption processes proceed slowly, and manual stirring must be carried out to accelerate the above process. Chloride has low surface tension and good wettability, so it is suitable for covering agent. Among them, chloride salts with molecular crystals such as CCl, SiCI, AICI, etc. can be used alone as purifiers, and ammonia salts with ionic crystals such as LiCl, NaCl, KCL, MgCl, etc. are suitable for mixed salt fluxes.
AdTech molten aluminum covering flux is white powdery fine particles. The main ingredients are chloride and villiaumite, together with other compounds. Spray it with gas from the refining jar as the carrier, sprinkling it directly to the surface of molten metal manually is permitted. Stir molten metal with covering flux to achieve inclusion removing purpose. It is used for aluminum, non-high magnesium-aluminum alloy, and strontium modifying aluminum alloy covering in the furnace, highly decrease metal loss caused by liquid oxidizing, and reduce oxidizing burning loss.