Application Of Metal Foam Foundry Filter in Aluminum Die Castings

In the production of non-ferrous metals, the easy oxidation of alloys is a headache for the industry, whether it is aluminum, copper or other alloys, it is very similar. At present, the use of effective solution cleaning and metal treatment technologies such as slag granulation and circular degassing has basically solved the related problems.

However, in foundry production, when the liquid metal is injected into the mold cavity from the holding furnace, there is still the problem that any turbulence at this stage will produce a thin scale. Not only are these defects never "healed", but they remain as weak points in the aluminum die casting and often fail the pressure test due to the gaps created between the two walls.

Metal foam foundry filter has been widely used in the non-ferrous foundry industry for many years. However, it is clear that the filter must have the following two separate characteristics: the ability to remove metal-entrained impurities and ensure a smooth, vortex-free flow of metal into the cavity.

When the first stream of liquid metal reaches the metal foam foundry filter inlet surface, there is a brief dwell, creating sufficient back pressure. This pressure is created by the metal head in the sprue, and once established, metal flow resumes as if the filter had never been present.

The turbulent flow in the gating system mostly occurs at the sprue and the front end of the sprue rod. If a metal foam foundry filter is placed across the sprue bar. Then the first metal flow will be blocked, and after the sprue is filled, it will be poured smoothly, thus preventing the formation of scale. Metal foam foundry filters are the only filters with this performance.

Using this kind of filter is not afraid of direct oxidation of aluminum die castings during the forming process, which is a very effective means.