Novel Zirconate Based Moulds for the Investment Casting of Titanium Alloy Melts
Besides the refractory, the choice of the binder is equally important because conventional silicate binders significantly impair the corrosion resistance. Although there have been successful attempts to develop CaZrO3 investment casting moulds, silicafree CaZrO3 investment casting moulds using a water-based binder have not yet been reported.
For the first time, graded CaZrO3 investment casting moulds using a silica-free water-based binder system were successfully produced . Moreover, the chemical, physical, thermo-mechanical and microstructural properties of the moulds were described. A combination of fine-grained primary coats and coarse-grained secondary coats resulted in a high surface quality as well as sufficient mechanical stability of the moulds. Investment casting of Ti6Al4V led to an exceptionally low hardness increase of the cast part, suggesting that only a slight corrosion reaction took place. Thus, the silica-free CaZrO3 investment casting moulds contributed to an improved investment casting of titanium alloys.