Experimental Design for Process Parameter Correlation to Dimensional Inaccuracies in Additive Manufacturing Processes

摘要

The objective of this work is to develop a comprehensive set of experiments for the investigation of the effects of Directed Energy Deposition (DED) processing parameters on dimensional accuracy. Dimensional accuracy, defined as the quantitative assessment of the agreement between the intended geometry and the final geometry of the deposited part, is understood to be one of the most important aspects of quality of an Additive Manufacturing (AM) process. This outcome is generally defined by the heat input affecting dimensions of the process including the capture efficiency of the injected powder, melt-pool size, and thermal cycling of the deposited part. Experiments were designed to generalize the effects of common DED processing parameters and their interactions on dimensional accuracy measured in situ and post-process. The experimental measurements assisted the development of validated, thermo-mechanical models that determined deformation-causing mechanisms in ways that traditional, measurement strategies fail. These models can act as a predictive tool in the assessment of the dimensional accuracy of subsequent directed energy depositions.