The effect of grain structure on the corrosion resistance of 7050 aluminum alloy

Multi-direction isothermal forging of 7050 aluminum alloy at 103s1strain rate and temperature of 3000C are observed. EBSD is used to characterize the grain structure, and the Vickers hardness and intergranular corrosion (IGC) properties are tested. The results of EBSD indicate that the sub-grains increase and the grain size decreases gradually as the pass of isothermal forging increases. The volume fraction of sub-grain has great effect on the corrosion resistance. The more sub-grains are included in the grain structure, the better the corrosion resistance and the mechanical properties. The grain size also influences the corrosion resistance, and the decreasing of the grain size is adverse to the corrosion resistance but is good for mechanical properties.