A method to decrease surface roughness in laser shock processing

• A rigid contact metal foil was covered on the workpiece in LSP.
• RCLSP can effectively decrease surface roughness on the scope of laser spot.
• There was an ultimate surface roughness for the workpiece treated by RCLSP.

A method called rigid contact laser shock processing (RCLSP) technique was presented in this paper. LY2 aluminum alloy samples with different initial surface topographies were treated by RCLSP with different technological parameters, and then surface topographies were carefully investigated with a non-contact optical profiler (NCOP) before and after RCLSP. Results showed that whatever the initial surface topography, there was a final value about surface roughness. Compared with the regular LSP technique, the RCLSP technique could effectively reduce the surface roughness.