Aluminum Alloy itself has a performance, it is easy to absorb the gas, it is easier to change his spots, in Aluminum Alloy casting process is the existence of such characteristics. But the final aluminum castings of this situation are certainly unfavorable, so we should try to avoid it. Let us first understand the process of the formation of this phenomenon.
Aluminum alloy will absorb hydrogen during casting process, and it will change with the change of temperature. That is, the higher the temperature of molten aluminum alloy, the more hydrogen will absorb. When the molten aluminum enters the mold, the liquid metal will decrease with the temperature, the solubility of the gas will also decrease, and the excess gas will be removed. But there will still be some of the gas remaining in the casting, which will form pores. When the pressure in the aluminum liquid increases, the surface of the hole will be smooth. But if the situation is the opposite, the surface of the hole will produce a lot of wrinkles, and the shape of the aluminum casting will affect it. Moreover, when the amount of hydrogen contained in the cast aluminum alloy is higher, the pinholes produced in the die castings will be more, so that the air tightness and corrosion resistance of the aluminum castings will be reduced, and the mechanical properties will also be affected. So if we want to improve this situation, we must pay attention to the melting conditions provided. If we can add some covering agents, the results will be different. In addition, the hydrogen content can be effectively controlled with the refining treatment of LV solution.
