M. Rutkevičius, E.A. Périgo
Keywords: direct metal laser sintering, fatigue strength, maraging steel, metal printing
Summary:The properties of parts made by Direct Metal Laser Sintering (DMLS) depend on multiple processing choices, including laser power, scan speed, direction of printing, powder quality, postprocessing approach, and others. Fatigue performance is one of the essential material property in functional part design process. However, fatigue performance is discussed in a limited manner for the materials used in Direct Metal Laser Sintering (DMLS). We prepared additively manufactured maraging steel samples and investigated their tension-tension (R=1) fatigue behavior for two different postprocessing approaches: i) standard heat treatment (SHT), and ii) hot isostatic pressing (HIP). HIP samples showed higher fatigue strength as compared to SHT process. Fractures originated from sample surfaces, occasionally near carbon and oxygen rich oxide inclusions. These results show that HIP could be used to enhance additively manufactured maraging steel fatigue performance to improve the lifetime of tools used in demanding applications.