Foundries are the factories which facilitate the production of metal casting. Casting is a process of melting the metal at very high temperature and then pouring the liquified metal in casts of different shapes. After filling the casts with the molten metal, it is left to solidify. Solidifying of the molten metal inside the casts forces the metal to take the shape of the cast. Different metals like aluminium, iron, tin copper, zinc, nickel etc are cast into different shapes as per the requirement. These foundries make use of alumina ceramic foam filter for filtering the molten aluminium and its alloys. After the metal is melted, it is purified using the filter before pouring it in to the cast. The filtering of the molten metal is required because most of the molten metal are highly reactive and react with the impurities present in the air.
Some physical characteristics of the alumina ceramic foam filter are:
• Porous: The filter is manufactured using ceramic and is made porous for the flow of the molten metals through the pores.
• Physical stability: Ceramic is chosen for the manufacturing of these products because ceramic is physically stable and has high melting point as compared to the metals. This prevents the ceramic filter to melt when the molten metal is poured. It can even work around 1200 degree Celsius.
• It dimension tolerance factor is around 0.5mm.
• Shock resistant
• Light weight
• Manufactured in different shapes and sizes i.e. round, square, honeycomb etc. as per the company’s requirement.
Some chemical properties of Alu filter are:
• Resistant to corrosion: Most of the metal get oxidised and gradually rusts. During molten form, the metals contain atmospheric oxygen. This atmospheric oxygen rusts the materials in contact, but Alumina Ceramic Foam Filter is completely rust free since it does not absorb the atmospheric oxygen.
• Chemically stable: It does reacts with the molten metal and is chemically inactive.
• Phosphate free
Why Alumina Ceramic Foam Filter?
When the metal is melted at high temperature, some percentage of air is trapped inside the molten metal. When the trapped air is solidified with the metal, then it creates a hollow space inside the metal which makes the material brittle. Because of the trapped air and impurities, the formations which are crafted in the casting will not be of the required strength which is turn reduces the lifespan of the material. So, in order to extract the complete strength of the metal, it should be filtered during its molten stage.
The material used in the making of Alu filter is aluminum oxide (which is around 85%), silicon dioxide of about 6%. There are different manufacturing companies which manufacture these filters as required by the foundries. Internet is the best place to get all the detailed specifications of these filters. There are other filters and the filters should be chosen as per the metal that is to be cast. You can even order the filters of the required shape from the filter manufacturing industries.