The invention relates to a
rapid prototyping and
investment casting combined dewaxing method facing a
turbine blade. The method includes the steps that an internal structure of a mould core is designed according to the appearance of the
turbine blade, closed small gas chambers are established in the internal structure of the mould core through the characteristic that the expansion coefficient of air is different from the expansion coefficient of a
rapid prototyping material, the small gas chambers are connected with external large gas chambers through supporting rib plates, the structure design is completed, and a
digital file is generated at the same time; operation is conducted on a three-dimensional model of the mould core of the
turbine blade, a mould core entity of a resin material is printed through a
laser rapid prototyping machine, and surface treatment is conducted at the same time for standby application;
slurry dipping, sand spreading and
drying hardening treatment are conducted on the mould core structure subjected to rapid prototyping, and a mould shell is obtained; and the obtained mould shell is heated, the large gas chambers communicate with the outside world at a
sprue gate, and the mould shell meeting the requirement is rapidly obtained with high quality. By means of the scheme mentioned above, the problem that the
ceramic mould shell expansion
breakage rate in dewaxing is too high when an additive manufacturing material is used as a
wax mould is effectively solved.