A kind of sodium-free refining agent for aluminum and aluminum alloy and production method thereof

Abstract

The invention discloses a sodium-free refining agent for aluminum and aluminum alloy, which consists of the following ingredients in percentage by weight: 15 to 25 percent of potassium aluminium fluoride, 5 to 15 percent of calcium fluoride, 10 to 25 percent of potassium carbonate, 10 to 25 percent of potassium sulfate, 5 to 15 percent of barium sulfate, 15 to 30 percent of potassium chloride and3 to 5 percent of anhydrous aluminium chloride. The invention also discloses a production method of the sodium-free refining agent. Because the sodium-free refining agent does not contain sodium salts, compared with sodium-containing refining agents, the sodium-free refining agent effectively solves the problem of antimony modification and phosphor modification influence caused by more or less sodium salt contained in the existing refining agent and overcomes the defects of alloy casting performance influence, melt flowability reduction and sodium brittleness possibly caused by the sodium element in aluminum-magnesium system alloy with the magnesium content being higher than 2 percent. A better use effect can be obtained in the antimony modification and phosphor modification alloys and high-magnesium-aluminum alloy. The invention belongs to the qualitative improvement on the prior art.

Description

technical field [0001] The invention relates to a sodium-free refining agent for smelting aluminum and aluminum alloys, and also relates to a production method of the refining agent. Background technique [0002] Aluminum and aluminum alloys are generally smelted under non-vacuum conditions. During this process, they easily absorb ambient gases and undergo chemical reactions to form inclusions, which greatly reduce the mechanical properties of the alloy. If the unpurified molten aluminum is directly produced into castings, the dissolved gas in the molten aluminum will float up with the decrease of solubility during the solidification process, and the oxidation inclusions in the casting will cause casting defects such as pores and cracks in the casting. Seriously affect the quality of castings, and even make the product scrapped. Therefore, it is necessary to purify aluminum and aluminum alloy melts to remove gases, metal oxides, non-metallic inclusions and other harmful ele...

AI Technical Summary

Problems solved by technology

But the defect of the prior art is: because the existing refining agents all contain more or less sodium salts, when added to the aluminum liquid, it can react with aluminum to form free sodium element and dissolve into the aluminum melt

In addition, sodium element can not only cause "sodium brittleness" in aluminum-magnesium alloys with magnesium content greater than 2%, but also reduce melt fluidity and affect the casting properties of the alloy

Sodium fluorosilicate can also react with aluminum to produce silicon tetrafluoride with a strong pungent smell, resulting in a large amount of smoke, worsening working conditions and polluting the environment

However, due to the important role played by sodium salt in the refining agent and the existing refining agents are constrained by the traditional concept of formulation, looking at the prior art, no sodium-free refining agent has been found.