Advanced Surface Modification of Binder Jet Additively Manufactured 316L Stainless Steel

Abstract

The primary objective of this study is to explore the efficiency of ultrasonic pulsed waterjet (UPWJ) peening, a novel surface modification technique, on binder jet additively manufactured AISI 316L stainless steel (BJ-SS316L). Given its wide usage in automotive, aerospace, and biomedical industries, BJ-SS316L was chosen as the focus material. The investigation primarily delved into UPWJ processing parameters, particularly traverse speed (ranging from 200 to 1000 mm/sec). Surface integrity and electrochemical characteristics after UPWJ treatment were evaluated, encompassing changes in surface roughness, topography, residual stress, hardness, and corrosion behavior (both uniform and pitting). Results identified an operational window that minimizes surface roughness and erosion while maximizing imparted compressive residual stress and uniform corrosion resistance, particularly favoring higher traverse speeds (800-1000 mm/sec). Detailed surface microstructure characterization using SEM, CSLM, XRD, and EDS shed light on the role of this novel waterjet mechanism in plastic deformation, material removal, and residual stress evolution. Additionally, electrochemical analysis techniques like EIS and cyclic PDP offered insights into how UPWJ surface modification affected corrosion resistance. Overall, UPWJ peening demonstrated significant potential as a surface enhancement treatment, with implications for improving BJ-SS316L performance in aerospace and biomedical applications. Further optimization of peening parameters is recommended to enhance fatigue strength, wear resistance, and resistance against various corrosion types following UPWJ treatment.