Precision casting is to melt the metal and cast it into the shell made of refractory material. The casting with complex shape can be cast by precision casting technology, which is close to the final shape of parts after forming. However, since the shell is in direct contact with the alloy melt during casting, the selection of shell material is the key to guarantee the casting quality for such metals with high melting point and strong chemical activity as
zirconium and zirconium alloy. The melting point of zirconium and zirconium alloy is (1852±10)℃, and the chemical activity is very high at high temperature, the melting state can react with most of the refractory materials, resulting in a layer of contamination on the surface of the alloy. For this reason, choosing refractory which does not react with zirconium melt is the key to obtain high quality zirconium casting. Refractory materials used in precision casting of zirconium and zirconium alloys mainly include graphite, refractory metal, refractory compound, oxide, etc.