Enhanced Laser Shock by an Active Liquid Confinement

This letter investigates a unique process to generate the enhanced laser shock with a higher pressure by applying an active liquid confinement — hydrogen peroxide (H2O2). The mechanism of fast chemical etching-assisted laser ablation is proposed. As a result, comparing with utilizing water as confinement, the efficiency of underwater laser shock peening of aluminum alloy 6061 is improved by 150%, and the ablation rate of pulse laser ablation of zinc is enhanced by 300%. This method breaks the major limitation of underwater pulsed laser processing caused by the breakdown plasma.