Tribo-corrosion behavior and mechanism of Ni-WC laser-clad coating in mineralizing solution.

Wang, Qin-Ying; Liu, Li-Yang; Zhang, Xing-Shou; Xi, Yu-Chen; Dong, Li-Jin; Bai, Shu-Lin

Laser cladding technology is an efficient method for repairing downhole drilling tools. The microstructural evolution and tribo-corrosion mechanism of Ni-WC laser-clad coating were investigated. The microstructural results indicate that the Ni-WC laser-clad coating is mainly composed of γ-Ni, WC, W2C, MxCy (M = W, Ni, Cr, Fe, Mo), M23C6 (M = W, Ni, Cr, Fe, Mo), and eutectic phases (CrC / MoC). Cl− exacerbates the corrosion of MxCy layer around WC particles by penetrating cracks, which further causes the shedding of the MxCy layer during wear. During tribo-corrosion, the Ni-WC laser-clad coating's open-circuit potential shifts negatively with increasing loads. Meanwhile, Ecorr shifted negatively and Icorr gradually increased, indicating more severe corrosion promoted by wear. The wear rate of coating is higher under open-circuit potential compared to that under pure mechanical wear, and mechanical wear is predominant in tribo-corrosion.

OPEN-circuit voltage; MECHANICAL wear; TRIBO-corrosion; SURFACE coatings; LASERS; FRETTING corrosion

Journal of Materials Science, 2025, Vol 60, Issue 7, p3408

0022-2461

Academic Journal

10.1007/s10853-025-10644-9