Influence of selected parameters of Selective Laser Sintering process on properties of sintered materials

Purpose: Presented researches aimed at determining the influence of parameters of Selective Laser Sintering (SLS), such as: laser power, point distance, scanning speed and exposure time on the density and compression strength of sintered material. Design/methodology/approach: Researches were performed using EOS 250XT (with maximum laser power of 250 W) and Renishaw AM 250 (with maximum laser power of 400W) systems for additive manufacturing. Investigated material was EOS - DirectSteel H20. There was prepared plan of the experiment incorporating above mentioned parameters of the sintering process. According to the DOE, samples for 25 sets of parameters were built, and later on investigated in order to measure and observe their densities and compression strength. Findings: Results of the performed studies enabled to work out the basis of the methodology for finding and optimizing parameters of the SLS process depending on the optimization criteria (i.e. physic-mechanical properties of the sample, sintering time, quality of the sintered surface). Basing on the knowledge gained during performed investigations, it can be stated that the sintering technologies supplied by the manufacturers of additive manufacturing systems can be significantly improved by modifying selected parameters. Practical implications: As the additive manufacturing allows to produce almost any shape, without limits existing in case of subtractive machining methods, it might be applied in the tooling industry for manufacturing moulds for injection moulding. Results of performed studies will find its application in making moulds with conformal cooling channels of durability comparable with solid / base materials. Originality/value: Selective Laser Sintering and Selective Laser Melting processes the additive manufacturing methods, are booming with its possible application fields, however it is still limited due to the main limitations of the process concerning durability and strength of sintered elements. The paper presents approach and test methodology enabling relatively simple and low cost (due to not large number of samples) optimization of SLS process enabling reaching properties of sintered elements comparable with those built of solid materials.