A General Algorithm for Inverse Modeling of Layer-By-Layer Liquid-Metal Deposition

Abstract

In order that freeform fabrication techniques, which entail layer-by-layer liquid-metal deposition, transition from prototyping to manufacturing, these techniques must be made reliable and consistent. Accordingly, detailed microstructural and thermal characterizations of the structures produced are needed in order to advance these fabrication techniques. The inherent complexity of layer-by-layer liquid-metal deposition, which is characteristic of energy and mass deposition processes in general, is such that process modeling based on basic theory alone, which represents the direct-problem approach, is extremely difficult. A general approach to overcoming the difficulties associated with this inherent complexity is the inverse problem approach. Presented here is a general algorithmic structure for inverse modeling of heat transfer that occurs during layer-by-layer fabrication. This general algorithmic structure represents an extension and refinement of an algorithmic structure presented previously and is potentially adaptable for prediction of temperature histories within parts having complex geometries and for the construction of process-control algorithms.