02 9月 Filtering aluminum-based alloys in foundry
Filtering aluminum-based alloys in foundry
Alloys of aluminum and other light alloys are particularly prone to the formation of unwanted inclusions.
A high magnesium content leads to the formation of oxide inclusions that adversely affect the quality of the metal.
The resulting slag inclusions, exfoliating particles of the furnace lining and the drain trough, along with other particles, form new phases and significantly reduce the quality of the casting.
Provide the highest level of quality of the casting can the most efficient cleaning of the melt. The use of foamed ceramic filter elements.
Ceralu® guarantees the achievement of the desired degree of metal purification.
Ceralu® ceramic filters are specially designed for the processing of molten aluminum and its alloys.
Ceralu® filters, consisting of porous alumina (Al2O3), vol. Operation 1150ºС.
The highest level of cleaning from non-metallic inclusions is achieved thanks to the triple action of Ceralu® filters:
mechanical retention of large inclusions by the surface layer of the filter, which acts as a sieve
the formation of filter cones that delay small inclusions
the deposition of the smallest inclusions on the developed inner surface of the foamed filter, providing a deep degree of filtration.
The porosity of Ceralu® filters, at the request of the Customer, can be selected in the range of 10-50 ppi (pores per inch). In practice, filters with a porosity of 30 ppi are typically used.
It is appropriate to note that the filtration efficiency increases as the filtration operation approaches the pouring of metal into the mold.
That is, it is possible, of course, to filter the metal when it is drained from the melting furnace to the bucket or to carry out the filtering process when overflowing from the shipping ladle to the transfer furnace, but it is most effective to install the filter in the gate system of the mold.
In this case, the metal will not be able to accumulate enough contaminants again to form defects in the castings.