Influence of added La2O3 on the microstructure, mechanical properties, and tribocorrosion resistance of TiB2–Ni plasma-sprayed coatings

To enhance the tribocorrosion resistance of 7075-T6 aluminum alloy in deep sea environments, TiB2–Ni coatings with varying La2O3 content were deposited on 7075-T6 aluminum alloy substrates using plasma spray technology. The effects of different La2O3 contents on the organization, structure, and properties of the coatings were analyzed. The results indicated that La2O3 incorporation suppressed brittle phase formation such as Ni3B; 1.0 wt% La2O3 addition reduced Ni3B by 16.9%. The coating's corrosion resistance significantly improved with La2O3 doping - the self-corrosion current density of the 1.0 wt% La2O3-doped coating decreased from 71.2 nA/cm2 to 30.2 nA/cm2.