Hydrogen and non-metallic inclusions are two major causes of porosity, reduced mechanical properties, and casting defects in aluminum products. An aluminum degassing machine provides an effective solution by continuously treating molten aluminum before casting.
An aluminum degassing machine typically uses a silicon nitride rotor to inject and disperse inert gas, such as argon or nitrogen, into the molten aluminum.
The basic process is:
Molten Aluminum → Inert Gas Injection → Bubble Dispersion → Hydrogen Removal → Inclusion Separation → Cleaner Aluminum
The rotor rotates at high speed inside the molten aluminum while inert gas is introduced through the rotor. This creates numerous fine bubbles that are evenly distributed throughout the aluminum melt.
Molten aluminum can absorb hydrogen from moisture and the surrounding atmosphere. When the metal solidifies, dissolved hydrogen can form gas pores.
The fine inert-gas bubbles provide a large surface area for dissolved hydrogen to diffuse into. The hydrogen-rich bubbles then rise to the surface and escape from the melt.
This significantly reduces dissolved hydrogen and helps prevent hydrogen porosity in aluminum castings.
The turbulent flow generated by the rotating rotor also helps bring non-metallic inclusions, such as oxides, toward the surface. These impurities can be removed together with the floating dross.
As a result, the aluminum melt becomes cleaner and more suitable for casting or further processing.
For production lines, an online aluminum degassing system can be installed directly in the molten aluminum flow path before casting.
This allows the melt to be treated continuously without repeatedly transferring it to a separate treatment vessel. Treatment parameters such as gas flow, rotor speed, and processing time can be adjusted according to the alloy and production requirements.
Effective molten aluminum degassing can help:
In short, an aluminum degassing machine uses fine inert-gas bubbles and controlled melt circulation to remove hydrogen and help separate inclusions from molten aluminum. By integrating online degassing into the production line, aluminum manufacturers can achieve more consistent and cleaner melt quality before casting.
