Influence of additive manufacturing process parameters on selective laser melting of CL91RW hot-working stainless steels
University of New Brunswick
In this thesis, the commissioning of a manufacturing metal 3D printer (Concept Laser M2) was undertaken. Commissioning of metal 3D printing requires an experimental approach. Materials manufactured in this fashion behave differently depending on both hardware factors such as laser power, speed, spot size, and environmental factors such as inert gas utilized (argon or nitrogen), calibration, auxiliary condition, and powder quality. A knowledge foundation including CAD preparation, employing parameter sets, print setup, and powder removal was developed. Several geometries were printed by employing parameters for CL-50WS (MS-1), CL-20ES (316L), and CL-91RW alloys. A preliminary study of laser power and speed and the effects on the porosity and melt pool morphology of additively manufactured CL50WS (MS-1) maraging steel were studied. This revealed the effects of processing parameters on the physical properties of the samples printed and explored some limitations of the machine. Forty cubic samples of CL-91RW were generated varying laser power and speed from 270 to 326 watts, and 900-1100 mm/s respectively. Sample density was determined using the Archimedes method and showed a density within 5% of the maximum, with the densest sample being 6.324 g/cm^3.