Dimensional Deviation Prediction Model Based on Scale and Material Concentration Effects for LPBF Process

Abstract

Additive Manufacturing (AM) processes generate parts layer-by-layer without using formative tools. The resulting advantages highlight the capability of AM to become an inherent part of product development. However, process-specific challenges such as high surface roughness, the stair-stepping effect, or dimensional deviations inhibit the establishment of AM at the industrial scale. Thus, AM parts often need to be post-processed using established manufacturing processes. Many process parameters and geometrical factors influence the dimensional accuracy in AM. Published results relating to these deviations are also difficult to compare because they are based on several geometries that are manufactured using different processes, materials, and machine settings. Laser Powder Bed Fusion (LPBF) is gaining in popularity, but one of the obstacles facing its larger industrial use is the limited knowledge of its dimensional and geometrical performances. Therefore, using it requires studying the process and improving the accuracy of the parts involved. This paper represents a new attempt to predict dimensional deviations of LPBF parts. During the project, the scale- and material concentration-related phenomena were implemented in a new image analysis model and applied to the as-built part. We carried out a comparison between the results of the proposed model with those obtained from numerical analyses and experiments. The model does not use finite element analysis, takes less time to compute, and provides reasonable prediction accuracy.