New technologies for characterizing aging processes in infrastructure materials

Extending the useful life of existing infrastructure facilities without sacrificing safety requires a better understanding of the aging processes in materials. The evolution of dislocation structures, compositional changes, and microfailure in material microstructures precede macrocracking and total failure, and hence their rates determine to a great extent a facility's lifetime. The size scale on which such microstructural changes occur requires detection/diagnostic techniques and analytical procedures with resolutions pushing the state of the art. When high resolution techniques are lacking, techniques for measuring effects of microscale changes can sometimes substitute. New techniques and procedures on both scales are described that will bring one closer to this understanding, and lead to capabilities to predict and extend a component's lifetime