Investigation of fully dense laser sintering of tool steel powder using a pulsed Nd:YAG (neodymium-doped yttrium aluminium garnet) laser

A 550W neodymium-doped yttrium aluminium garnet (Nd:YAG) pulsed laser was used in the solid freeform fabrication (SFF) process to form fully dense sintered parts. Tool steel powder was chosen due to its wide acceptance in the tool-making industry. Unlike many processes applying either thermoplastic binder or metals of low melting points in the powder mixture, this process enables a direct fusion of material to solid parts without a further post-processing step. This paper presents a methodology and the results of high-power laser sintering of tool steel powder. The investigation includes the effects of various process parameters on the fully dense laser sintering results on a single bead and single layer and the related scan strategy to build up solid cubes. This process could eventually produce pre-forms with complex material structures rather than finished tools or parts.