Microstructure, crystallographic texture, and enhanced wear and hardness properties of 2 wt.% Nb-modified 316L stainless steel fabricated by wire arc additive manufacturing at different deposition orientations

Abstract Wire Arc Additive Manufacturing (WAAM) has become a highly dependable manufacturing technique in the 21st century due to its cost-effectiveness, shortened production time, and reduced material wastage. Compared with other additive manufacturing techniques such as selective laser melting and electron beam electron beam melting, WAAM offers significantly higher deposition rates, lower feedstock costs, and greater capability for producing large-scale metallic components. Due to these advantages, WAAM has gained considerable attention in industries requiring large structural components and complex geometries. WAAM excels particularly in fabricating complex geometries. However, defects remain a significant challenge associated with WAAM-deposited stainless steel. The objective of this study is to investigate the influence of (Nb) addition on the microstructural characteristics, mechanical properties and mechanical behavior of WAAM deposited 316 L fabricated under different build orientations and interlayer time. WAAM deposited cubes 316L stainless steel were fabricated at the three deposition orientations (0°,67°, and 90°) with interlayer times of 2 and 5 min. The addition of 2% Nb was intended to modify the microstructure and enhance the mechanical and tribological properties of the deposited material. Details microstructural characterization were performed using electron backscatter diffraction (EBSD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). These techniques were used to analyze grain morphology, phase distribution, crystallographic orientations, and microstructural variations along the build direction. Mechanical and tribological properties were evaluated through hardness measurements and dry sliding wear tests. wear experiments were conducted using pin-on-disk tribometer to investigate the coefficient of friction (COF) and wear behavior of the WAAM—deposited material. The results indicate that build orientation significantly influences the tribological performance of the deposited material. For the 0° orientation, the coefficient of friction ranges from 0.57 to 0.64, whereas the 67° orientation shows a slightly lower COF ranging from 0.55 to 0.58. The addition of 2% Nb contributes to improved microstructural stability and enhanced wear performance. The novelty of this research lies in the incorporation of Nb into WAAM- fabricated 316L stainless steel to improve microstructural characteristics, mechanical and tribological properties.