Functionalization of carbon-bonded alumina filters through the application of active oxide coatings for steel melt filtration

Carbon-bonded alumina filters for steel melt filtration are increasingly used by industries. Their potential regarding the material characteristics and the filtration efficiency appears, however, not used in full measure up to now. In the course of the present work, a new approach, due to the application of active oxide coatings, whose chemical phase equates to that of the nonmetallic oxidic inclusions in the steel melt, was created. The main emphasis consists of the generation of cold-applied, active alumina, spinel, and mullite coatings. Coatings have been developed due to the variation of sintering temperatures and a thermal pretreatment, which lead to increasing cold crushing strength. A basic understanding regarding the adhesion and the interface between the oxide coating and the carbon-bonded filter substrate has been created. Therefore, the essential factor is traceable back to thermal-related mechanisms.