Geometry and surface characteristics of H13 hot-work tool steel manufactured using laser-directed energy deposition

This research focuses on specimen geometry and the associated surface roughness of H13 hot-work tool steel, processed using laser-directed energy deposition additive manufacturing, and varying both the powder feed rate and the laser scanning speed. Under the examined conditions, the test sample measurements of length and width did not vary, but the sample heights were significantly affected by the scanning speed. An increase in scan speed resulted in 'underbuilding', while a decrease resulted in 'overbuilding', as might be anticipated. The top surface roughness of the samples was found to be greater than the side surface roughness, due to the capture of extra powder particles. For the single-track and multitrack clad samples, the surface roughness was increased when decreasing the scan speed. The addition of a draft angle, when producing 3-D components, was shown to reduce the side surface roughness. Using a finer layer thickness results in overbuilding the target height, while a coarser layer thickness results in underbuilding. Finally, the surface roughness exhibited no clear trend when the layer thickness was changed.