Platinum crucible is widely used in melting colored glaze materials to ensure its composition and melting quality.The failure platinum crucible for melting colored glaze in muffle furnace was analyzed.The results show that brittle cracks occurr at the crucible bottom

which are attributed to the reaction of platinum and silicon or carbon to generate the brittle phases with low melting points.Silicon and carbon are from the silicon carbide hearth plate

and its inclusive free carbon and the adhered glaze material on its surface can promote the oxidation of silicon carbide

and increase the embrittlement risk of the crucible bottom.Therefore

when platinum crucible is used for melting colored glaze

silicon carbide hearth plate must be avoided to be adopted.