Publication

Materials & Advanced Manufacturing (MAM)
2019

Tech Pub Qualification Scheme Development for Arc Directed Energy Deposition Additive Manufacturing

by D.D Harwig; W. Mohr; S. Hovanec; J. Rettaliata; R. Hayleck; E Handler; J.Farren

Abstract

A prescriptive qualification scheme was completed for Arc Directed Energy Deposition (DED) metal Additive Manufacturing (AM) processes for austenitic single-sided builds. Robotic arc DED AM qualification builds used stainless steel consumables with the gas metal arc welding - pulse (GMAW-P) process. A matrix of standard qualification builds were made to develop, evaluate, and recommend the preferred process qualification build schemes. The qualification scheme explored a range of heat inputs, deposit sizes, and deposition rates; and the effects of interpass temperature that can be a limiting productivity factor for robotic arc DED metal AM builds. The standard qualification builds evaluated the effects of thickness (thin and thick geometric build features) where the process deposit (heat input) and process build thermal features (preheat and interpass temperature) are controlled over smaller ranges. The builds were examined with both ultrasonic and radiographic inspection, and a standard set of destructive tests (tensile, bend, macros, etc). Arc DED stainless steel builds showed good tolerance and consistent properties over the range of features tested. A prescriptive qualification scheme provides a clear path to accelerate implementation of high impact DED AM technology. Additional standard qualification build designs and testing plans are underway for ferrous materials, and with and without integrated build plates to provide prescribed qualification requirements for the most common applications of arc DED AM processes.