Aerospace Part Integration Utilizing Additive Manufacturing in IN-718

Airframe and engine products are often composed of numerous components, which typically require intricate fastening mechanisms for assembly.  Some of these assemblies are also required to function in harsh environments of high stress and/or high temperature. The cost of these assemblies is typically very high due to use of superalloy materials such as IN-718 and associated operations like machining and component assembly.  For these reasons, major aerospace manufacturers are looking into possible alternative manufacturing methods such as Additive Manufacturing as means of part cost savings. Part reduction through consolidation in complex assemblies is seen as a potential cost driver, and has encouraged companies to begin investigating the full capabilities of this process.  However, it has been shown that parts produced through additive manufacturing typically have lower mechanical properties relative to wrought material.  This decrease in mechanical performance, especially in fatigue sensitive applications, often becomes a challenge on aerospace manufacturers in trying to implement the technology into a production environment.

The topic of this paper is a hybrid approach to additive manufacturing, where critical areas of components are still made from wrought material, but other shapes/features of the product, which do not have critical mechanical requirements are fabricated using additive manufacturing.  Wrought part features such as bosses and pads must be provided 100% coverage during a forging/rolling process, and then eventually machined out.  Having to perform forge and rolling processes and then secondary machining operations on features that are not load critical, is both time-consuming and costly.   With a hybrid additive approach, there is a potential to impact both the cost and complexity of the secondary machining operations, as well as enable easier fabrication and assembly of complex parts.