Hardness and tensile properties of metals subjected to aging conditions

Abstract

Many metals used in engineering applications are exposed to aging conditions such as ultraviolet radiation and moisture. Aged metals are expected to lose their designed mechanical properties, and it was desired to relate a degraded local property to other homogenous properties. To study the aging effect, steel and aluminum were tested with reproduced variables in an accelerated weather testing chamber. Multiple tensile specimens of steel and aluminum were created to undergo accelerated Q-Lab Ultraviolet testing in the presence of radiation, heat and moisture. Accelerated aging resulted in decreasing surface hardness correlating with the tensile strength and elastic modulus for both steel and aluminum. The study also investigated the change in hardness through the depth of specimens resulting from aging, exhibited more consistently in steels. The overall strongest correlations existed in steels, between surface hardness and tensile strength, analogous to other studies. Modeling linear relationships for metal lifetime forecasts from hardness has been supported by this study. Outcomes can be expanded upon with more elaborate finite element analysis if desired in future experimentation.