Enhancement of tribological properties by fabricating gradient structure and MoS₂ coating on the surface of 06Cr19Ni9 stainless steel

Abstract Stainless steel is extensively used in civil engineering and mechanical industries due to its superior corrosion resistance and mechanical performance. Nevertheless, its surface is prone to wear, which can compromise component functionality and introduce safety concerns. The present study developed a composite structure consisting of a gradient microstructure layer combined with a pure MoS 2 coating on the surface of 06Cr19Ni9 stainless steel. The fabrication process involved ultrasonic shot peening using α -Al 2 O 3 particles, followed by thermal spraying. Fretting friction and wear using the ball-on-disc method demonstrated a notable improvement in tribological performance. The composite structure achieved a remarkably low friction coefficient of 0.16 under a normal load of 15 N representing a 74.19% reduction compared to a mechanically polished sample. However, when subjected to a higher normal load of 50 N, the friction coefficient increased significantly. Despite a relatively higher wear rate, the composite structure effectively safeguarded the metal matrix from substantial wear during testing. The enhanced tribological properties were primarily attributed to the synergistic interaction between the gradient microstructure layer and the MoS 2 coating. These findings underscore the potential of this composite structure to significantly improve the wear resistance and extend the operational life of 06Cr19Ni9 stainless steel.