Influence of different deposition strategies on the microstructure and mechanical properties of the laminated heterostructured material with ER130S-G HSS and 316 L SS fabricated by WAAM

Abstract

Two groups of laminated heterostructured materials (LHM) thin walls with different deposition strategies and the corresponding single-material thin walls were successfully fabricated by wire and arc additive manufacturing (WAAM) technology. The deposition strategy for the LHM-1 thin walls was to change the deposited material every layer, and for the LHM-2 thin walls was to change the deposited material every two layers. The results indicate that changes in the deposition strategy could affect the volume fractions and distribution locations of different phases in LHM samples, thereby influencing the mechanical properties. Due to the dilution effect, when the two materials in the LHM samples were deposited on each other, the chemical composition of the two regions deviated. Two sets of LHM samples were prepared using the same volume fraction of 316 L stainless steel (SS) and ER130S-G high-strength steel (HSS), and the LHM-1 samples showed higher tensile strength and lower elongation. In HSS areas of the LHM-1 sample, every layer consisted of the martensite microstructure. In the HSS areas of the LHM-2 sample, one layer was composed of the martensite microstructure, while the adjacent layer was a mixed microstructure of bainite and ferrite. For LHM samples, the softer regions experiencing greater deformation during the tensile process. The lower Schmid factor of the FCC phase in the LHM-2 sample compared to the LHM-1 sample, makes it easier for the former to yield, thereby resulting in superior ductility of the LHM-2 sample. The results of the investigate reveal that the possibility of controlling the microstructure and properties by altering deposition strategies in WAAM technology.