Experimental Study For Micro Laser Peen Forming Of 8011 Aluminum Alloy Foil

As the trend of miniaturizing, integration, multi functions of electronic and mechanical products, as well as extensive applications of aluminum alloy, using plasma shock waves that generated by pulsed laser to cause plastic deformation of sheet became a well prospective field. Based on the review of research status and theory basis of micro laser peen forming, this paper analyzed its advantages and prospect of forming, and considered effects of every influence factor to forming results comprehensively. Experiment device of self-design and single factor experiments were utilized to research forming performance of 8011 aluminum alloy. At the same time, digital photos for forming parts were taken, and the reasons for forming success and forming failure were discussed. Digital camera and Photoshop software were adopted to calculate the real area of laser spots, and height of forming parts was measured by sliding caliper. Some meaningful conclusions were obtained:(1) Laser power density or laser energy is the major influence factor for forming. As the increase of laser power density or laser energy, the peak pressure of the plasma shock waves became higher, and thus bigger deformation amount could be obtained(2) the more pulse numbers, the more deformation of sheet; (3) as the increase of the diameter of round concave die, the sheet's deformation amount became lower. The materials and mechanical mechanisms of these phenomena were preliminary presented. Metallographic testing method were adopted to analyze microstructure change of cross section of deformation area of the sample, and some small etch pits were found on the sample's surface.We use finite element mesh division program FEMB and commercial program LS-DYNA to numerically simulate the micro laser peen forming process, and the deformation amount were gained. At the same time, the deformation amounts were compared with experimental results, and they were found to be very close between them. This indicates the simulation model is reasonable, and the simulation method is proper. The model could be better improved as the further development of micro plastic forming theory and experiment.