熔制琉璃用铂金坩埚的失效问题

铂金坩埚广泛用于琉璃的熔制,以保证其成分和熔融品质。对在箱式电阻炉内熔制琉璃的失效铂金坩埚进行检测分析,发现坩埚底部出现脆裂是由Pt与Si、C发生反应形成低熔点脆性相所致,Si、C来自SiC质炉底板,其内含的游离Si及表面粘附的琉璃料将促进SiC的氧化,增加坩埚底部脆裂的风险。因此,采用铂金坩埚熔制琉璃时,要避免使用SiC材质炉底板。

Failure of Platinum Crucible for Melting Colored Glaze

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.