Inducing Known, Controlled Flaws in Electron Beam Wire Fed Additive Manufactured Material for the Purpose of Creating Non-Destructive Inspection Stand

To induce controlled defects in wire feed E-Beam additive manufacturing for making NDT standards, MER will work with Applied Optimization (AO) to develop a Physics based ICMSE based process model of defect formation which captures the influence of closed loop control parameters of power, build temperature, wire feed rate and deposition path. This model will be verified by experiment on a closed loop controlled wire feed platform initially using power setting and build temperature as the control parameters with real time monitoring of melt pool temperature to develop known defects. The model will have the capability to control not just the E-beam free form fabrication (EBF3) process but also the Plasma Transfer Arc wire feed system which MER currently uses, to allow either platform to be used for making initial defect containing samples. Defects due to lack of fusion (LOF) and those due to hot cracking will be targeted by the initial study. A unified model of hot cracking will be developed including solidification range of the alloys and superimposed thermal residual stress field. In phase I samples made with known defects on the PTA platform will be compared with similar defects in NASA samples made by EBF3 to confirm the physical basis of the ICMSE control model.