Directionally solidified investment casting with improved filling

摘要

A method of making a directionally solidified casting by casting a melt in a mold cavity of an investment mold having a core therein to form an internal casting surface feature involves evacuating the mold cavity while the investment mold is disposed on a chill member with the mold cavity communicating to the chill member, and introducing the melt into the evacuated mold cavity about the core so that the melt contacts the chill member for unidirectional heat removal and directional solidification. Then, gaseous pressure is applied to the melt cast in the mold cavity rapidly enough after introduction in the mold cavity to reduce localized void regions present in the cast melt as a result of surface tension effects between the melt and the core.