Wax support optimization strategy for high-precision hollow turbine blade patterns manufacturing

Hollow turbine blades require precise wall thickness to ensure structural reliability and cooling performance. The wall thickness accuracy of the wax pattern is a critical dimension index for hollow blade investment casting, which is controlled by the positional accuracy of the ceramic core in the mold. The current wax-support method for positioning the ceramic core presents two challenges. The geometric retention of the wax support in the hot-wax-liquid environment cannot be guaranteed. The wax support thickness has not been accurately analyzed and calculated, and the optimal thickness remains unexplored considering the deformed ceramic core. To address these problems, this study proposes an optimization strategy for manufacturing hollow turbine blade wax patterns integrated with control of thermal behavior, adaptive geometric compensation, and surface-fidelity control. Initially, to ensure the geometric retention of wax supports in a hot-wax-injection environment, the influence of shape and radial size on their heat resistance was investigated by theoretical and numerical analysis. Next, an adaptive thickness compensation strategy for wax supports was established to address individualized surface errors in ceramic cores. Finally, the combination of machining parameters that meet the surface quality requirements was obtained through milling experiments. The proposed method was validated through wax-pressing experiments, which compared it with the conventional method. The results showed a significant improvement in ceramic core positioning, with a 58.6 % reduction in the mean absolute error of the wax pattern wall thickness. This study provides a novel pathway for the precision control of wax pattern wall thickness of hollow turbine blades.