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

Abstract

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