BN Type Y-CZ is based on the most thermodynamically stable oxides of Yttrium Oxide (Y2 O3 ) and Calcium Zirconate (CaZrO3 ), both with melting points over 2300 C. This combination yields 60 mol% Y2 03 and 40 mol% CaZrO3 on heating over 1000 C. Most importantly, unlike other Yttrium Oxide based coatings, Type Y-CZ is usable in air atmospheres as well as inert/vacuum to temperatures in the 1000-2000 C range; and the coating bonds well to all substrates – ceramic, graphite, metal. Due to the high stability of the coating, Type Y-CZ is suitable for use with very reactive molten metals.