A Repair Method for Damage in Aluminum Alloy Structures with the Cold Spray Process

Aluminum alloy structures may be damaged due to wear or corrosion while in service. These damages will bring about huge financial costs, as well as a huge amount of energy consumption. There is an urgent need to search for an appropriate repair method in order to solve this problem. In this research, the cold spray process was used to repair the damages by using a mixture of powders with Al and Al2O3. A 7N01-T4 aluminum alloy plate with a factitious pit was regarded as the damaged sample. The microstructure, mechanical properties, and corrosion behavior were studied. The results showed that there were no visible perforative pores or cracks in the repaired areas. The microhardness of the repaired areas was in the range of 57.4–63.2 HV and was lower than that of the 7N01-T4 aluminum alloy. The tensile strength of the repaired samples was markedly improved compared with the unrepaired samples. The alternate immersion test results indicated that the repaired samples had the lowest rate of mass loss compared with 7N01-T4 and the unrepaired samples. After alternate immersion tests for 504 h, the repaired samples were covered with dense corrosion products. The repaired samples had a superior corrosion resistance compared to that of 7N01-T4. Thus, the cold spray process is a method of repairing damage in aluminum alloy structures.