Influence of surface liquid segregation on corrosion behavior of semi-solid metal high pressure die cast aluminium alloys

The corrosion behavior (in chloride medium) of the surface layer of SSM-HPDC plates of alloys 7075-T6 and 2024-T6 was compared with that of the wrought alloys 7075-T6 and 2024-T6. Potentiodynamic testing was performed in deaerated 3.5%NaCl solution. In separate tests, the open-circuit potential was monitored in aerated 3.5% NaCl for 30 min after immersion. The electrochemical tests show that there is no significant difference in the pitting potential of the wrought alloys and that of the Cu-enriched surfaces of the SSM-HPDC alloys.