A Key Advance in Process Acceptance for Rapid Manufacturing by Electron Beam Melting for Aerospace Applications

Direct-digital fabrication by electron beam melting (EBM) offers enormous promise for numerous rapid-manufacturing applications including specialized aerospace parts requirements and aircraft sustainment needs. Substantial previous EBM fabrication and testing have been jointly conducted by NASA-Marshall and Boeing to achieve process approval under the guidelines of Aerospace Material Specification AMS 4999, Proposed Rev A, which is in draft form and under control of the SAE Aerospace organization. Recent results from additional interdepartmental work through IMST at NC State University (NCSU) in collaboration with Boeing have shown consistency with acceptance requirements both independently and when pooled with previous results. It has also provided a comparison between feedstock powder types manufactured by two alternative processes about which there has been uncertainty regarding whether each would deliver comparable material properties. This talk will present findings from the recent NCSU-Boeing project and show how this work fits into the larger picture of process approval, parameter space approval and flight hardware approval requirements. The legacy of ongoing collaboration between facilities using different machines, different feedstock types, at different locations will lead to qualification of this new technology as an approved process for manufacturing flight-approved parts by direct-digital EBM manufacturing.