Phase Interaction between ZrB₂–SiC Composite Ceramics with Oxide Melts

Abstract

The paper studies the mechanism of interaction between the ZrB₂–ZrSi₂–SiC composites and dross-type oxide melts formed during the combustion of low-reactive carbons containing oxide rocks up to 30–40 vol.%. It is established that the silicon carbide from the surface layer of the composite interacts with the iron oxides to form spherical deposits of the FeSi_x phase at 1350–1550 °С in the wetting process and in contact with the dross during 10–50 h. In the composite–dross contact area, a thin (~7.5–30.0 μm) layer of ZrО₂ and SiО₂ oxides is formed (depending on the amount of SiC and ZrSi₂), the latter serving as a protective film, preventing the composite ceramics from corrosion in the oxide melts. The optimum composition of the ZrB₂–ZrSi₂–SiC ceramics which can be used as corrosion-resistant in the oxide melts is determined.