FILTERS FOR LIGHT METALS

摘要

Filters for filtering molten light metals comprise a reticular foam formed from a composition comprising graphite, wollastonite, silica and a borosilicate glass and consist of a crystalline phase comprising graphite and wollastonite dispersed in a substantially amorphous matrix of borosilicate glass. The filters can readily be machined accurately from large pieces of the filter material and they do not pick up moisture from the atmosphere when stored. The borosilicate glass used to produce the filters preferably has a softening temperature (T1) in the range of 600 DEG C, more preferably 650 DEG C to 900 DEG C and a melting temperature (T2) in the range of 700 DEG C to 1100 DEG C, as measured according to the tests in German Standard DIN 51730.