The corrosion behavior of multicomponent porous MAX phase (Ti0.25Zr0.25Nb0.25Ta0.25)2AlC in hydrochloric acid

Multicomponent porous MAX phase (Ti0.25Zr0.25Nb0.25Ta0.25)2AlC was fabricated through powder metallurgy. The corrosion behavior in different concentrations of HCl was studied through electrochemical and immersion tests, and porous Ti, 316 L stainless steel, Ta2AlC and Ti2AlC were taken as the comparisons. The corroded samples' phase composition, microstructure, and passive film have been characterized using XRD, SEM, TEM, EDS, and other analyses, from which the corrosion mechanism is summarized. The results reveal that (Ti0.25Zr0.25Nb0.25Ta0.25)2AlC exhibits great corrosion resistance in 6 M HCl, with the lowest mass loss rate, corrosion current density, and the highest polarization resistance compared with other materials. The excellent performance of (Ti0.25Zr0.25Nb0.25Ta0.25)2AlC in HCl is considered to be the result of the combined action of four elements in the M position. This work is expected to provide ideas for the research in the corrosion field of MAX phases.