Compressive residual stress generation at crack tip in bulk metal using acoustic cavitation

Abstract

We propose to generate compressive residual stress at the crack tip in the bulk metal by introducing acoustic cavitation to the crack tip. We conducted experiments using pre-cracked specimens to measure compressive residual stress at the crack tip achieved by the acoustic cavitation. In the experiments, the pre-cracked metal specimens were subject to an acoustic load with a frequency of 20 kHz to introduce acoustic cavitation to the crack tip. We found that the acoustic cavitation generates a significant amount of compressive residual stress at the crack tip and the generated compressive residual stress effectively retarded the crack growth.