Method for preparing super-hydrophobic aluminum alloy surface through flat-topped laser peening

A method for preparing a super-hydrophobic aluminum alloy surface through a flat-topped laser peening, comprising the following steps:

• pretreating an aluminum alloy surface;
• evenly coating the aluminum alloy surface with a nanoscale carbon powder layer;
• performing an unconstrained peening treatment on the aluminum alloy surface using a square spot flat-topped nanosecond pulsed laser with the nanoscale carbon powder layer serving as an absorption layer, wherein beams are kept perpendicular to the aluminum alloy surface all the time;
• a laser irradiation on the nanoscale carbon powder layer increases an absorption rate of a laser energy;
• a part of the nanoscale carbon powder converts into plasmas after absorbing the laser energy;
• and a shock wave generated by a rapid expansion of the plasmas stirs and mixes a melted carbon powder and a remelted material of the aluminum alloy surface to increase a carbon content near the aluminum alloy surface;
• and
• removing a residual carbon nanopowder after the flat-topped laser peening, and reducing a surface energy of an aluminum alloy material through a low-temperature heat treatment to obtain the super-hydrophobic aluminum alloy surface with micro-nano multiscale structures.