Broadband surface acoustic wave attenuation in metals using chirp compression and dispersive interdigital transducers.

Abstract

This study presents a non-destructive method for estimating surface acoustic wave attenuation, which is highly sensitive to microstructural features, especially at high frequencies. The method uses a single wideband dispersive interdigital transducer (IDT) that remotely emits acoustic waves at the sample's edge. Chirp compression of the temporal displacement response is achieved by correlating the excitation signal with the spatial configuration of the IDT's electrodes. This technique generates high-amplitude pulses with a sufficient signal-to-noise ratio, critical for enabling accurate attenuation estimation over a frequency range (15-70 MHz). Results from nickel and aluminum demonstrate the method's effectiveness for rapid material characterization.