Effect of the ceramic mould composition on the surface quality of As-cast titanium alloy

To best understand the metal/mould interaction reactions during the casting process, we must consider the mould composition and the thermodynamic aspects present at the liquid/solid interface during the casting. In the present work three types of mould ceramic materials were selected. Materials were received as powders to test the reactivity with molten titanium. The selected commercial investment systems were: Rematitan-Plus(R) (R-Plus), Rematitan-Ultra(R)RG (R-Ultra), and Ticoat-Manfredi(R) (T Manfredi). The chemical composition for the refractory ceramic powders is given. Wax moulds for castings were prepared according to the procedure described. Metallic rings were used as inclusions. Castings were carried out using an argon-casting machine, type Easy Ti(R), with induction heating and a centrifugal liquid metal injection system.