Abstract by Scott Smith
Chemistry and Biochemistry
Signal Decay of Second Harmonic Generation Signal
Non-destructive testing(NDT) seeks to determine the likelihood that a component will fail without further compromising it, allowing for its continued use. Current NDT methods typically probe metallic components for microscopic cracks, which are associated with fatigue and are the immediate precursors to failure. These methods are of limited sensitivity because they cannot detect the small-scale plastic deformations(PD) which precede microfracture formation. Further, some forms of damage like tensile loading don’t present these features before failure. Our research has shown second harmonic generation(SHG) spectroscopy to be sensitive to PD in 2024 Al and is a viable means of NDT. The SHG response we use in this analysis decays rapidly with sampling and suggests modification of the surface. My project aims to explore this trend, and to correlate it with specific structural changes.