Effects of graphene addition on the mechanical, friction and corrosion properties of laser powder bed fusion 316L stainless steel

Abstract

Laser powder bed fusion of 316 L (LPBF-316 L) has been known to exhibit high ductility but low strength, along with strong corrosion resistance and weak anti-friction properties. Graphene is commonly utilized as a reinforcement phase in metals fabricated through LPBF, as this process helps reduce the tendency of graphene to agglomerate. Therefore, it is crucial to investigate the impact of incorporating graphene into the LPBF-316 L alloy, aiming to enhance toughening and anti-friction properties while maintaining the original corrosion resistance. Various concentrations of graphene were incorporated into 316 L powder and processed using LPBF. The study examined the impact of graphene concentration on the electrochemical, mechanical, and friction properties of the resulting composites. The study revealed a significant reduction in corrosion current from 8.05 ± 0.6 × 10−7 A/cm2 to 6.61 ± 0.8 × 10−8 A/cm2. The 15-day immersion experiment further validated that the incorporation of graphene contributed to enhancing the stability of corrosion resistance. Additionally, the presence of graphene led to improved strength and ductility in LPBF-316 L through grain refinement and precipitation. Notably, samples containing 0.2 wt% graphene exhibited a tensile fracture strength of 927.4 MPa and ductility of 54.75%. In addition, the compressive fracture strength of 2342.8 MPa, both surpassing that of LPBF-316 L. Furthermore, the study investigated the impact of graphene content on the friction of LPBF-316 L, revealing that graphene addition increased matrix hardness, reduced COF, and enhanced wear resistance. Overall, the findings suggest that graphene serves as an effective reinforcing agent for 316 L stainless steel matrix composites, enhancing mechanical properties, friction resistance, and wear resistance while preserving original corrosion resistance.