Corrosion behaviors at different temperature based on the ultrafine-grained structure of Al-Fe alloy

Electrochemical tests and immersion experiments were employed to investigate the corrosion behaviors of the Al-Fe alloy (AA8176) processed by equal channel angular pressing (ECAP) in 3.5 wt% NaCl solution at different temperature (25 degrees C and 0 degrees C). It was worked out that after ECAP, with the reduction of grain size, the fragmentation and uniform distribution of precipitated phases increased the number of pitting corrosion but reduced its size, the increase of grain boundary density and the reduction of precipitated phase aggregation decreased the degree of intergranular corrosion. AA8176 changed from local corrosion to uniform corrosion, which provides a new idea to improve the corrosion resistance of Al-Fe alloys.

Automated summary

After ECAP treatment, Al-Fe alloy shows an increase in the number of pitting corrosion but a decrease in the size of pit corrosion, due to the fragmentation and uniform distribution of precipitated phases. The increase in grain boundary density and the reduction of precipitated phase aggregation also contribute to the decrease in intergranular corrosion. This study provides a new approach to improve the corrosion resistance of Al-Fe alloys by transforming the corrosion mode from local to uniform.