Effect of combined grinding-burnishing process on surface integrity, tribological, and corrosion performance of laser-clad stellite 21 alloys

Herein, the influence of the grinding-burnishing on surface integrity, mechanical properties, and corrosion performance of Stellite 21 alloys coating deposited by laser cladding is investigated. The as-clad specimens are first ground followed by further modification by ball burnishing at forces of 424 N and 509 N. Results show that the grinding-burnishing enhances surface finish by lowering R${}_a$ from 2.6 to 0.73 µm and R${}_z$ from 13 to 4.9 μm, respectively. Surface porosity is found to decrease from 3.8% to 0.9%. Hardness is increased from 609 HV to 702 HV, with a surface alteration as deep as 250 μm, while wear resistance increases by reducing worn volume from 4.15 to 2.95 mm${}^3$. Because of high hardness, the grinding-burnishing increases impact resistance by lowering indent depth by 20%. Grains flatten and surface undulations are remarkably reduced due to burnishing. Finally, grinding-burnishing at 509 N improves the corrosion resistance by increasing positive corrosion potential from -0.41 to -0.14 V and lowering corrosion current density from 6.34 × 10${}^{-4}$ A cm${}^{-2}$ to 2.19 × 10${}^{-5}$ A cm${}^{-2}$, as compared to grinding. This synergistic grinding-burnishing can be a plausible post-treatment route for the laser-clad alloys. (© 2022 The Authors. Advanced Engineering Materials published by Wiley‐VCH GmbH)