Layer-level AISI 316L-18Ni (300) Maraging multi-material fabrication via Laser-Powder Bed Fusion

Abstract

Overcoming most of the limitations of conventional subtractive techniques, Laser-Powder Bed Fusion (L-PBF) is a widely adopted technology that allows the fabrication of metallic components with complex geometries. Available machines can work with a large variety of materials; however, multi-material printing is limited to inter-layer fabrication, i.e., each layer is made out of a single material. In this work, we aim at expanding the multi-layer printing capabilities of L-PBF to intralayer manufacturing (i.e., two different materials in the same layer), overcoming the previous limitations. To investigate the effectiveness and validate the proposed method, two widely used steels are used as powders to manufacture bi-material specimens, i.e., the AISI 316L austenitic stainless steel and the 18Ni (300) Maraging steel. Based on metallurgical and mechanical testing evidence, the results show that the method is repeatable and capable of fabricating strong and tough intralayer interfaces. While weak interfaces between materials with rather different mechanical properties are common in multi-material printing techniques, our method allows us not only to produce bi-materials with stronger interfaces but also to reduce discontinuities to those normally found in additive manufactured components. These results are obtained without any modifications to the machine and with low-cost additional equipment, opening the way for easy and cost-effective implementation.