Quality assurance is one of the most important challenges in powder bed fusion. Binding faults are triggered by locally too thick powder layers and consequently insufficient connection to the layers below. Therefore, the knowledge of the local powder height could be one essential aspect in future quality assurance routes. In this work, multi-detector electron optical imaging based build surface topography measurements of the melted surface and the subsequently applied powder layer are combined to determine the local powder height in situ. The local powder height is measured during the build of a complex part, purely from experimentally measured data. Differences to theoretical continuum-based considerations are rationalized and the role of the process-cycle induced temperature evolution on recorded build surface topographies after melting and powder application revealed. The widths of height histograms, originating from segmented part and powder areas, are identified as key elements to assess the quality of the applied powder layer and the melted surfaces. The developed measurement principle and derived process signatures can serve as basis for future quality assurance routines in series production environments.

Additive manufacturing (AM) enables the production of complex, customized parts through its layer-by-layer process. However, high surface roughness and geometrical distortions often necessitate post-processing, with machining being the most widely used method. Therefore, understanding the machinability of AM parts is essential for selecting appropriate tooling and machining parameters. This requires insight into the material’s microstructure and mechanical behavior, which are significantly influenced by AM process conditions. Rapid solidification and steep thermal gradients inherent to AM processes result in distinct crystallographic textures and columnar grain growth, which affect the material’s response during machining. Due to inconsistent experimental findings in the literature, there is a need for microstructure-informed constitutive modeling. This study presents a comprehensive constitutive model to predict flow stress and cutting forces during orthogonal cutting, incorporating key strengthening mechanisms: thermal activation, solid solution, lattice resistance, grain boundary influence, and forest dislocation interactions. AM Inconel 718 which is widely used in critical industrial applications was fabricated using laser powder bed fusion (LPBF). Microstructural features and solute atom concentrations were characterized using electron backscatter diffraction (EBSD) and energy-dispersive X-ray spectroscopy (EDS), providing input for the constitutive model. Model validation was performed through orthogonal cutting experiments under various cutting conditions. Cutting forces were measured using a dynamometer, and chips were examined via scanning electron microscopy (SEM). The model predicts flow stress and cutting forces within 10% of experimental values. Moreover, it enables a quantitative evaluation of each strengthening mechanism’s contribution, providing insight into their individual effects on the machining behavior of AM-fabricated parts.