DESIGN DETAILS PROCESS COMPETES WITH DIRECT TO METAL LASER SINTERING C JITEN SHAH, PRODUCT DEVELOPMENT & ANALYSIS (NAPERVILLE, ILLINOIS) Member Aristo-Cast Inc. (Almont, Michigan) set out to prove the extreme detail on the interior of the part was possible through 3D printing for investment casting. Th e printed investment casting The shell (PICS) successfully produced the fuel nozzle without requiring expensive or complex tooling or patterns. Th e PICS could reduce The cost by 50%. omplex and intricate, duplex fuel nozzles for aircraft are being printed using the direct to metal laser sintering (DMLS) process. Aircraft companies have said they tried and failed to make the same part via investment casting, so DMLS seemed like the best and perhaps only option. But AFS Corporate 2 3 5 7 THE KEY DRIVER FOR THE DESIGN WAS MULTIPLE-PART CONSOLIDATION BY INCORPORATING VARIOUS SUB-COMPONENTS AND FEATURES INTO A ONE-PIECE PART, WHICH IS NEAR-NET SHAPED AT LOWER COST AND LEAD TIME. • Th e interconnected fuel passage-ways (1) were diffi cult to form via traditional investment casting shell production, but 3D printing made it possible. • Design engineers must consider the minimum wall thickness (2) required from castability, fl uidity and solidifi cation of the liquid metal during casting and validate with casting process simulation to ensure the desired quality and overall success. 18 | CASTING SOURCE | JUL/AUG 2020