Molten Aluminum Refining Degassing

When the hydrogen content in the aluminum casting reaches a certain value, its mechanical properties will be seriously reduced. And hydrogen embrittlement will occur, causing the casting to be scrapped. In order to prevent cracking defects caused by hydrogen in the alloy, AdTech offers molten aluminum refining degassing system to remove hydrogen from the aluminium material.

AdTech molten aluminum refining degassing system has an ultra-long life furnace body, uses new high-silicon molten material manufacturing technology. The degassing rotor, heater protection sleeve, and thermocouple protection sleeve are all made of silicon nitride (Si3N4) ceramic manufacturing technology. Degassing Unit is installed between the furnace and the casting machine. It is to exclude hydrogen and other residues contained in molten aluminum and its alloys.

The degassing system adopts gas blowing method, also known as the float method. It is mainly to form many fine bubbles after blowing inert gas into the aluminum liquid.

The initial pressure of hydrogen in the bubble is zero, and there is a pressure difference of hydrogen at the interface between the bubble and the aluminum liquid. So the hydrogen dissolved in the aluminum liquid is continuously sucked into the bubble. This inhalation process will not stop until the pressure of the hydrogen in the bubble and the hydrogen in the aluminum liquid are equal. After the bubbles float out of the liquid surface, the hydrogen in the bubbles escapes and enters the atmosphere.

In addition, the bubbles meet the oxide inclusions in the melt during the passage through the melt. The inclusions are adsorbed on the surface of the bubbles and float to the surface of the melt with the bubbles to be removed.

Therefore, the bubble rising process can not only bring out hydrogen to achieve the degassing effect, but also can bring out the oxidation inclusions, so as to achieve the effect of refining.