Micro-macro relationship between microstructure and mechanical behavior of 316L stainless steel fabricated using L-PBF additive manufacturing

Abstract

Compared to traditional production techniques, additive manufacturing (AM) of metallic components has several benefits, mainly little material waste and more design freedom. AM process based on laser powder bed fusion has many key process parameters including scanning speed, layer thickness, build direction, and printing power. Each one of these parameters influences microstructure, and hence macro-mechanical behavior of the manufactured part, as the part microstructure plays a critical role in determining the mechanical properties. This work aims to address a relationship between micro-structure and macro-mechanical behavior of AM fabricated parts made of 316L Stainless Steel. Both as-built and heat-treated samples are being used for experimental testing and microstructure characterizations. Arcan fixture is used to evaluate the macro-mechanical fracture behavior of the material under mode-I, mode-II, and mixed-mode conditions. Microstructure evaluations of the fracture surfaces are done using scanning electron microscopy and X-Ray diffraction techniques. Finally, a correlation between micro-scale characteristics and macro-mechanical behavior is obtained together with different AM process parameters.