Stereolithography-Based Manufacturing of Molds for Directionally Solidified Castings

Directionally solidified components, such as single crystal turbine blades, are typically grown using shell molds prepared using a lost wax process that begins with injection-molded wax positives. These positives have complex designs, are manufactured in low volumes, and are made using expensive tooling. Here we investigate the potential of replacing these injection-molded positives with plastic patterns created using stereolithography. By using 3D printing instead of injection molding to create the positives, we can dramatically reduce tooling costs and leverage the freedom of design offered by 3D printing to create more intricate turbine blade designs. While using 3D printed positives to create molds for shape castings was one of the earliest examples of rapid prototyping of metallic components, the present work highlights the potential of extending this approach to molds used for growing single crystal parts.