Metals and alloys with high vapor pressure can reduce the gas content due to evaporation adsorption. Alloying elements that have a greater binding force to the gas increase the solubility of the alloy. In contrast to the elements with less binding force to the gas, increasing the solidification temperature range of the alloy, especially the element which lowers the temperature of the solidus line, tends to cause pores and looseness in the ingot.

Copper, silicon, manganese, and zinc all reduce the gas solubility in aluminum alloys, while titanium, zirconium, and magnesium are opposite.

Effect of temperature on casting of aluminum alloy profiles such as 6061 aluminum plate

The higher the temperature of the molten metal, the faster the thermal movement of the metal and gas molecules, and the faster the diffusion rate of the gas inside the metal. Therefore, in general, the solubility of a gas in a metal increases as the temperature increases.

Effect of pressure on casting of aluminum alloy profiles such as aluminum rods

Pressure and temperature are two interrelated external conditions. Pressure factors also have a significant impact on the ability of metals to absorb gases. As the pressure increases, the gas solubility also increases.

Other factors in the casting of aluminum alloy profiles such as aluminum rods

Due to the presence of an oxide film on the surface of the metal melt and its density, it hinders the diffusion of gas into the interior of the metal, which greatly slows down the dissolution rate. If the oxide film is destroyed, it will inevitably accelerate the metal absorption of gas. Therefore, any operation that destroys the oxide film on the surface of the melt during the casting process is disadvantageous.

For any chemical reaction, the time factor is always beneficial to the continuous progress of a reaction, eventually reaching its saturation state in which the gas dissolves in the metal. Therefore, the longer the exposure time in any case, the more inhalation. In particular, exposure of the melt to high temperatures for extended periods of time increases the chance of inhalation. During the smelting process, the 6061 aluminum plate always strives to shorten the smelting time to minimize the gas content of the melt.