Plasma transferred arc intergranular and transgranular orientation processing route for enhanced nickel-matrix coating corrosion and wear resistance

This study introduces a novel Plasma Transferred Arc Welding (PTAW) processing route for depositing high-performance NiCrBSi coatings on structural steel. The innovation of this work lies in the strategic use of a low standoff distance (5 mm) in combination with low arc currents (60 A and 70 A) to tailor the coating's microstructure for superior wear and corrosion resistance, addressing a significant challenge in extending the lifespan of machine tools. The coating prepared at 60 A (C60A) demonstrated a significant improvement in properties compared to the one prepared at 70 A (C70A). Quantitatively, the C60A coating achieved a maximum microhardness of 754.0 HV_0.5, a 26.8 % reduction in corrosion current density, and a 38 % lower wear rate (p < 0.01). These enhancements are attributed to a more refined microstructure, a higher volume fraction of beneficial FCC texture components, and a lower density of geometrically necessary dislocations (1.04 × 10¹³ m⁻² for C60A vs. 1.08 × 10¹³ m⁻² for C70A). This research provides a viable pathway for fabricating durable and reliable Ni-based coatings for demanding industrial applications.