Ceramic Crucible Corrosion by Heavy Metal Oxide Glasses, part I: Pheonomenological Study

摘要

Heavy metal oxide (HMO) glasses have received special attention due to their optical, electrical and magnetic properties. The problem with these glasses is their corrosive nature. In this work, three ceamic crucibles (Al_2O_3, SnO_2 and ZrO_2) were tested in the melting of the system 40 PbO-35 BiO_(1.5)-25 GaO_(1.5) (cation-%). After glass melting, crucibles were transversally cut and analyzed by scanning electronic microscopy (SEM), coupled to microanalysis by energy dispersive spectroscopy (EDS). Results indicated that zirconia crucibles presented the highest corrosion, probably due to its smallest grain size. Tin oxide crucibles presented a low corrosion with small penetration of the glass into the crucible. This way, these crucibles are an interesting alternative to melt corrosive glasses in instead of gold or platinum crucibles. It is impotrtant to emphasize the lower cost of tin oxide crucibles, compared to gold or platinum ones.