| Abstract Scope |
Robotic Directed Energy Deposition (DED) offers a strong business case for reducing automated manufacturing and repair programming costs, high productivity and first-time part quality, and significantly reduced schedules and ship outage repair costs. New quality systems requirements, processes and methods need developed to support implementation of robotic arc DED (i.e. digital welding) manufacturing and repair of marine components. In this NSRP RA project, robotic DED is being developed for Nickel Aluminum Bronze (NAB) propellers and other shipbuilding manufacturing and repair applications. A key objective was to develop a quality system framework that met the requirements of both NAVSEA and ABS metal additive manufacturing standards. ABS requirements also addressed design approval where NSWCCD has design responsibility for Naval propellers. This project focused on manufacturing quality requirements for both standards.
The project compared the ABS and NAVSEA DED quality requirements to existing quality systems used for fabrication. The DED quality framework was divided into three workflows: DED manufacturing operations, procedure & report requirements, and data retention. New quality procedures and reports are required for machine calibration (digital twin and post-processor), build model files, process interrupts and in-process correction logging, in-process monitoring data, post-DED processes (heat treatment, pre-nondestructive testing (NDT) machining), conformance evaluation sample properties, final NDT and dimensional evaluation, and part certification. A digital manufacturing storage file structure is required to manage / retain all this data, and support manufacturing workflows and routine conformance audits. These DED quality system procedures will be audited and qualified in 2024 in conjunction with implementation of qualified gas metal arc DED procedures, a LCU DED part verification build (first article), and a certified LCU DED demonstration propeller. The DED quality system framework and new procedures should be adopted by shipbuilding supply chains to accelerate the implementation of metal DED of marine components. |