Rapid Tooling in Investment Casting: Investigation on Surface Finish of Mould Produced with 3D Printed Patterns

Mould development in investment casting is time consuming process. In addition cost involved in preparation of die and other tooling justified when large volume production is required. Application of 3D printed pattern as an alternative of wax pattern enables faster production as well as provides design flexibility for complex parts. In present work, investigation is carried out on surface quality of 3D printed ABS and PLA patterns to replace conventional wax patterns. Post processing of 3D printed ABS and PLA patterns were carried out to improve surface finish as it removes line marks formed by layered fabrication on printed patterns. Acetone smoothing was applied to finish the ABS pattern and sanding was done to finish PLA pattern. Improvement in surface finish of mould is observed to greater extent with PLA and ABS patterns as compared to wax patterns. From the experiments it is concluded that primary slurry retention and slurry wetting is better with ABS and PLA patterns as compared to wax patterns that contributes to the improvement in surface finish of mould.