Ways to increase the productivity of L-PBF processes

Abstract

One of the main limitations of additive manufacturing (AM) technologies consists in the relatively low build rate. Low productivity discourages companies from investing in AM machines, thus limiting the market of additive technologies. Machine manufacturers have introduced new solutions to their designs to increase the build rate, some of them are described in this paper. However, design improvements are not the only method to accelerate the process. The paper specifies factors that influence the build rate in the laser powder bed fusion process and provides an analytical assessment and comparison of the significance of how they affect its productivity. The influence that a change in selected parameters has on the process and the influence of multi-laser systems on its productivity are analysed in terms of the melted material quality. The processes from which the data for analysis were obtained were carried out on an SLM 280 machine with single- and dual-laser versions as well as on an SLM 500 with four lasers. Two types of samples, solid and thin-walled, both of the same volume, were tested. The data under analysis were the process times for both geometries, manufactured with different sets of parameters from the adopted range. Processing times were analysed to determine the main effects and interaction effects for extreme values of a given parameter. The height of the melted powder layer had the greatest influence on the build rate, which turned out to be greater even than the application of a two-laser system.