A design framework for build process planning in DMLS

Abstract

Additive manufacturing (AM) of metal parts using the direct metal laser sintering (DMLS) process employs layer-wise melting of powder material to fabricate geometrically complex models. However, this option to build high-end metallic products comes with technical challenges, spreading along the overall process chain. Therefore, the powder bed fusion (PBF)-based metal-AM technology, such as DMLS, requires extensive research, addressing part quality and build repeatability issues, primarily induced by underlying thermal activity at the melt-pool level. At the same time, no software tool is available, beyond the commercial regime for the vital process planning of metal-AM using DMLS. This paper presents an open-source framework named MarcSLM, which integrates the thermally aware segmentation of the powder layer and build process control. First, a modular framework is proposed, based on metal-AM digital thread and then, its implementation is explained. The process starts with the preparation of a build platform, where multiple geometries are arranged with individualized process parameters. Afterwards, the laser exposure vectors are generated based on thermal region segmentation of sliced data. All the build data are packaged into a custom-build machine code, which is designed to derive the laser-galvanometer scanner duo as a synchronized entity and control the powder feedstock servomechanism. This article is organized into the introduction section explaining the requirement and the novelty of this research. Following which, the methodology and implementations are explained. The digital and experimental results verifying the proposed framework will be presented towards the end.