Experimental investigation on dynamic characteristics and strengthening mechanism of laser-induced cavitation bubbles

• The dynamic features of laser-induced cavitation bubble are investigated.
• Wall-leaning effect of cavitation bubble is proved.
• The relations between relative distance parameter γ and strengthening mechanism of cavitation bubble are discussed.
• A new strengthening method based on laser-induced cavitation shotless peening (CSP) is provided.

The dynamic features of nanosecond laser-induced cavitation bubbles near the light alloy boundary were investigated with the high-speed photography. The shock-waves and the dynamic characteristics of the cavitation bubbles generated by the laser were detected using the hydrophone. The dynamic features and strengthening mechanism of cavitation bubbles were studied. The strengthening mechanisms of cavitation bubble were discussed when the relative distance parameter γ was within the range of 0.5–2.5. It showed that the strengthening mechanisms caused by liquid jet or shock-waves depended on γ much. The research results provided a new strengthening method based on laser-induced cavitation shotless peening (CSP).