Performance of silicon oxide-based ceramic cores made by rapid prototyping for single crystal turbine blades

Abstract

The shortcomings of long period, high cost and slow response in making ceramic core by using investment casting method were overcome by using stereolithography and gel casting, which is of great significance for the rapid manufacturing of the single crystal blades with complex structure. The evolution rule of high temperature strength and shrinkage of silica based ceramic core was studied. The addition amount of nano zirconia power and aluminum powder and sintering time were explored. The micro morphology of the sample was characterized by field emission scanning electron microscope, and the high temperature strength of the sample was measured by three-point bending method. The results show that: when the mass fraction of nano zirconia power is 2.16%, the mass fraction of aluminum powder is 9.8% and the sintering time is 3.9 h, the maximum high temperature strength value of silicon oxide-based ceramic core reaches 14.3 MPa. The value of high temperature strength meets the needs of directional solidification casting of single crystal blade. There are no obvious cracks on the surface of the prepared ceramic core, the structure is complete and the molding quality is good.

Keywords

• hollow turbine blade
• ceramic core
• high temperature strength
• response surface metho-dology