Characterization of Aging Behavior of AA6061 Aluminum Alloy Through Destructive and Ultrasonic Non-destructive Testing Techniques

An experiment was conducted to characterize microstructural and mechanical behavior of AA6061 alloy during an artificial aging treatment through destructive and ultrasonic nondestructive techniques. Identical aluminum plates of AA6061-T6 aluminum alloy were solutionized at a parts per thousand 800 K, followed by quenching and artificial aging at 493 K up to 8 h. The microstructural evolution was analyzed using scanning electron microscopy. The variations in hardness, yield stress, and ultimate tensile strength with respect to aging time were discussed. Besides, ultrasonic parameters velocity and attenuation were measured and correlated with the microstructural evolution as well as certain mechanical properties. The ultrasonic measurements showed a good correlation with the microstructural features and mechanical properties of the alloy during aging, whereby an excellent correlation was found between the longitudinal wave velocity and strength properties of the aged specimens. The longitudinal wave velocity was found to be directly related to the hardness with a correlation coefficient of 0.99.