Case Studies in Digital Foundry™

Closed Impeller for Fluid Handling- Stainless Steel 316

DDM designed a closed impeller typically used for fluid handling applications. The impeller is 100mm in diameter and 25mm in height with complex internal vanes. DDM then designed a monolithic shell for casting this impeller, printed and fired the shell and delivered it to partner foundry Signicast. The castings were poured at Signicast in Stainless Steel 316L. Chemistry, metallurgical quality, mechanical properties, and surface finish are consistent with typical production investment castings.

Payoff: No tooling, no soluble wax cores, no wax, no 3DP patterns, no finishing.

Oil Pump for Aviation - Aluminum A357

DDM partnered with Signicast to produce an oil pump for aviation hydraulic applications. This is a complex Aluminum A 357 casting with multiple curvilinear internal channels. When made through conventional methods, this casting requires 12 sets of unique tooling to produce the soluble wax cores for the internal passages, and 1 set of pattern wax tooling for the external geometry. DDM engineered, printed, fired and delivered monolithic shells with integrated cores to produce the casting through two steps namely, “ready to pour” printed shell production, and metal pouring.

Payoff: 12 sets of tooling eliminated, no wax pattern, no soluble wax cores, no finishing.

Knee Implant - Cobalt Chromium Moly Alloy

DDM partnered with Signicast to produce a prototype knee implant. DDM sourced the CAD file for the implant from the public domain. DDM then engineered, printed, fired and delivered monolithic shells with optimized gating schemes to Signicast. Signicast produced the implant castings in Cobalt Chromium Moly Alloy with a composition similar to ASTM F75, the standard Cobalt alloy for implants.

Payoff: No wax or 3D printed pattern, high resolution features possible without machining.

Fighter Aircraft Roll Ratio Servo Cover - Aluminum A357

DDM partnered with Signicast and Moog to demonstrate rapid investment casting of a roll ratio servo cover for a legacy fighter jet. 3D scans of the part were combined with 2D drawings to develop a CAD model. DDM delivered printed and fired shells to Signicast. The entire process from CAD to first casting was completed in 39 days just in time for the AFWERX Fusion 2020 event. It takes over 100 days to source this part through the current casting supply chain. The alternative of metal 3D printing can be cost prohibitive and may not be able to meet the alloy specification for this part as defined in the technical data package.

Payoff: No tooling, no wax pattern, rapid on-demand delivery of certified spare parts for legacy systems.