Large-Size Component Printing by Selective Laser Melting for Gas Turbines: Benefits, Challenges and Mitigation.

While additive manufacturing by Selective Laser Melting (SLM) is becoming more widely used in gas turbine industry due to its relatively high dimensional accuracy, the sizes of the components commonly produced these days are relatively small (<~500mm). Large component printing however is becoming more available due to the recent advancements in SLM printers, especially those equipped with multiple lasers and large building area. In this presentation, we are reporting some of the unique challenges of printing large components by SLM, based on our experience on a few gas turbine parts. Some of the challenges include larger thermal stress, longer printing time, limitations in Design for Additive Manufacturing (DfAM), powder usage and post processing. We will also discuss some of the mitigation measures that could be employed to lessen the issues, as well as the special considerations in printing large components from powder acquisition, process development, post heat treatment to post machining/cutting. This presentation aims to provide practical knowledge and awareness for existing and potential SLM users and manufactures to better facilitate the use of SLM for large component printing.