Multiscale Process Control in Metal Additive Manufacturing

Tremendous gains have been made over the past several years to improve understanding of defect formation in laser powder bed fusion (LPBF) processes and develop predictive material models that can guide process optimization. However, while control of defects may be achievable at a given length scale for a given material, there remain significant challenges in efficiently predicting and mitigating defects wholistically across length scales, e.g. grain-, melt pool-, feature-, part-scale. In this talk I will present efforts to improve the efficiency and accuracy of predictive models that describe defect formation across the multiple relevant length scales found in LPBF. Beyond predictions, effective means to implement defect mitigation solutions are also required. Efforts to manipulate the optothermal coupling in both custom and commercial LPBF systems will be discussed that begin to address such requirements. Prepared by LLNL under Contract DE-AC52-07NA27344.