Wear and corrosion resistance of TiAlSi-Nix (x = 0, 5, 11, 17, 23 at%) multi-principal component alloy coating prepared by ∞ oscillating laser cladding

To improve the wear and corrosion resistance of key components and ensure the safe operation of offshore equipment, we applied an ∞ oscillating laser to prepare a TiAlSi-Ni composite coating. The effects of Ni addition on the composition, microstructure, corrosion resistance and mechanical properties of the coating were experimentally investigated. The results showed that the coating mainly presented an interdendritic - dendritic structure, and the S4 coating with 17 at% Ni had the best wear and corrosion resistance. In the reciprocating sliding friction and wear test at 10 N and 30 N, the wear rates were 0.83 and 1.66 × 10−7 mm2·N−1, respectively, which is 1/5 and 1/3 of TC4 under this load. The S4 also had the largest passivation interval and passivation film stability. The internal and external double-layer film structure ensures that it is not corroded by corrosive medium. The Ti3Al/TiNi semi-coherent interface and lattice distortion gave the Ti3Al-Ti2Ni and TiAl-TiNi eutectic interfaces a high bonding strength. Moreover, the “labyrinth effect” produced by the lamellar eutectic structure further improved the corrosion resistance. This work provides a new method for obtaining coatings with high adhesion and wear and corrosion resistance for offshore platforms. •“∞” oscillating improve the properties of deposition layer.•The diffusion impedance of the dense outer passivation film obstructs Cl- penetration.•The Semi-coherent relation promotes the improvement of wear and corrosion resistance.