Bulk Al-Al9Co2 alloys: Microstructure, corrosion behavior and hydrogen evolution kinetics

Two Al alloys with 1 and 3 at% Co were prepared by arc-melting of Al and Co in argon. The corrosion behavior of the as-cast alloys was studied in a NaOH aqueous solution (0.01 M). Furthermore, a hydrogen evolution was investigated by volumetric measurements. The results were compared with pure Al. The alloy with 1% Co was the least corrosion resistant and evolved most hydrogen. The presence of Al9Co2 in the eutectic facilitated hydrogen evolution and contributed to corrosion activation. The results can be used for the design of Al-Co alloys for hydrogen generation.

Automated summary

Two Al alloys with 1 and 3 at% Co were prepared and their corrosion behavior and hydrogen evolution were studied in a NaOH solution. The alloy with 1% Co showed the lowest corrosion resistance and the highest hydrogen evolution. The presence of Al9Co2 in the eutectic contributed to enhanced corrosion and hydrogen evolution. These results can be applied in the design of Al-Co alloys for hydrogen generation.