Pure titanium casting into titanium-modified calcia-based and magnesia-based investment molds

Calcia is the most stable oxide for molten titanium at high temperature. In this study, pure titanium casting into calcia- and magnesia-based investments was investigated. Experimental results show that adding the proper amount of titanium powder into calcia- and magnesia-based investments can increase the thermal expansion value, at 800 °C, of both investments. Pure titanium castings in the calcia-based group have better expression at the interface reactivity and the VH. However, castings in magnesia-based group have better results for the investing and the dimensional accuracy.