LAUSR

Abstract The aim of this research work is the adjustment of the conventional investment casting process for the single crystal casting of thin-walled near net shape specimen with cast wall thickness down to 0.4 mm. Polymer models for manufacturing of shell molds for investment casting of Ni-based superalloys were produced by additive manufacturing from three different thermosets and one thermoplastic. Temperature dependent mass change, thermal expansion and burnout behavior of the polymers were investigated. All thermosets turned out to have inappropriate burnout behavior due to high thermal expansion. Smoothed polyvinyl butyral (PVB) could be burned out without cracking the shell mold. High quality thin-walled single crystal Ni-based superalloy M247LC was cast successfully in shell molds manufactured using polyvinyl butyral (PVB) models which were subsequently burned out and thereafter the shell molds were sintered.