Surface roughness control of LY2 aluminum alloy milled surface subjected to laser shock wave planishing processing

In this paper, Laser shock wave planishing processing (LSWP) is performed on the CNC milling surface of LY2 aluminum alloy. The influence of contact foil roughness on the surface roughness of the workpiece is analyzed. The results show that in a single LSWP, the coarser the contact foil, the higher the removal of the milling marks. The contact foil is not smoother and more effective. For surfaces with different roughness, there is a corresponding contact foil with appropriate roughness, which can minimize the roughness of the workpiece. By selecting a contact foil of suitable roughness, LSWP can greatly reduce the NC machining surface with high initial roughness and simplify the CNC milling process. The surface roughness of CNC milled surface can be reduced from 3.12 μm to 0.977 μm after one LSWP impact. In multiple LSWPs, the surface roughness of the contact foil in the previous LSWP treatment will seriously affect the effect of the latter LSWP, so the choice of film contact roughness is particularly important. The surface roughness of CNC milled surface can be reduced from 3.07 μm to 0.562 μm after two LSWP impacts.