Influence of retrogression and re-aging treatment on intergranular and exfoliation corrosion of 1973 aluminum alloy

The influence of retrogression and re-aging treatment (RRA) process on mechanical properties and the intergranular and exfoliation corrosion of 1973 aluminum alloy were investigated using hardness measurement, constant tensile properties test, polarization curve measurement, intergranular and exfoliation corrosion tests, optical microscopy (OM) and transmission electron microscopy observation (TEM). The results show that the intergranular corrosion trend is the same as that of exfoliation corrosion after different aging treatments, and the RRA process order of descending corrosion resistance is that: 200°C, 60 min; 180°C, 60 min; 180°C, 40 min; 180°C, 20 min; T6. The strength and the resistance of intergranular and exfoliation corrosion of 1973 aluminum alloy can be enhanced with the retrogression and re-aging treatment at 180°C. As the retrogression and re-aging treatment at 200°C for 1 h the corrosion resistant of 1973 aluminum alloy increases, however its strength decreases greatly. Retrogression and re-aging at 180°C for 1 h is a suitable processing for 1973 aluminum alloy to have good combination properties.