Mechanical Electrochemical Study of Susceptibility to Stress Corrosion Cracking of Aeronautical Alloys Al6061-T6 and Inconel 600

For the aeronautical industry corrosion has always been an important problem, especially within the aircraft maintenance, falling into great expenses to study and prevent the formation of it on some elements that are indispensable for the aircraft’s service. The external stresses or the existing loads joined with the atmospheric environment can provoke degrading mechanisms that combined cause cracking on the material by means of tension and early failures. This phenomenon, called Stress Corrosion Cracking (SCC), produce a great loss of mechanical strength, without evidence of the material’s damage and loss, but it can produce fast mechanical fracture and catastrophic failures. This study’s objective is to evaluate and compare two materials commonly used in the aeronautical industry, Al6061-T6 and Inconel 600, to identify which one presents a better resistance to SCC in salty, caustic and acid environments. Mechanical tests were performed using low speeds on a CERT (Constant Extension Rate Test) machine, varying the environment, its pH and concentration. Simultaneously, the electrochemical noise tests were also performed to determine the corrosion speed and link the Stress-Deformation plots with the electrochemical patters recorded, giving results more complete and accurate to the behavior of the materials when in service.