To fabricate coarse yttria grain with closed pores for improving the thermal shock resistance of yttria, a proper additive wasfirstly selected among calcium nitrate, cerium nitrate, and neodymium nitrate. Then, the appropriate amount of calcia addedinto yttria was investigated. Finally, the corrosion resistance of the fabricated yttria crucible was compared with pure calcia,and magnesia crucible. The results reveled that by adding 1 mol% calcia, lots of closed pores were distributed in coarse yttriagrains and the composite has superior thermal shock resistance and excellent corrosion resistance with titanium alloy. Thenewly fabricated yttria might fit for the melting and casting of pure titanium and its alloys.

Keywords: Additive, Yttria, Interface, Titanium alloy