Effects of aging on corrosion behavior of a novel nano TiC/Ti refiner refined Al-Zn-Mg-Cu alloy were investigated by means of soaking corrosion

polarization curve and stress crack corrosion.The results indicate that after soaked in 3.5% NaCl solution for 192 h

the corrosion rate of peak-aged and over-aged Al-Zn-Mg-Cu alloy refined with TiC/Ti reach 0.756 5mm/a and 0.361 3mm/a respectively.The fracture time of stress crack corrosion are 72.2h and 50.1h with the peak-aged alloy refined with TiC/Ti at NaCl and NaCl+H

2

O

2

solution

respectively

while at over-aged

they are 221.2h and 80.8h

respectively.The resistance of stress crack corrosion at over-aged is the higher than that of ones at peak-aged.The wider PFZ can decrease significantly the corrosion resistance of alloy refined with TiC/Ti at peak-aged

however

at over-aged

the coarse and discontinuous phase preciphated from grain boundary and the narrow PFZ can improve the corrosion resistance.