A new approach to selective laser melting (SLM) could alleviate long-standing challenges in additive manufacturing of high-density metal parts. Researchers at Lawrence Livermore National Laboratory and its Accelerated Certification of Additively Manufactured Metals Strategic Initiative used computer simulations to gain better insight into the SLM process and refine process parameters such as laser power and speed, distance between laser scan lines and scanning strategy. The study focused on 316L stainless steel, although the researchers said this new method could also be applied to other metal powders. “We mine the simulation output to identify important SLM parameters and their values such that the resulting melt pools are just deep enough to melt through the powder into the substrate below,” said Chandrika Kamath, a researcher at LLNL who led the study. SLM produces 3-D parts layer by layer by fusing particles of metal powder with high-energy laser beams. Some applications require parts that are very dense because pores and voids are typically the weakest part of the material. The study’s findings will be used to certify properties of metal parts that are built using SLM, according to the researchers. The research was published in the International Journal of Advanced Manufacturing (doi: 10.1007/s00170-014-5954-9). For more information, visit www.llnl.gov.