Precipitation hardened aluminium alloys are a very important and infallible material in industry mostly because of their good density/strength ratio. They are used especially a lot in aviation industry despite a large increase in epoxy matrix reinforced carbon fiber composite materials. Because of the exposure to extreme conditions in aviation, such as high-cycling fatigue and corrosive degradation, additional technology for surface hardening is neded. The modern method of Laser Shock Peening (LSP) is slowly but persistantly displacing the conventional kinetic method of Shock Peening (SP), because it allows more workability control, absence of contamination and imparting of higher residual stress into the thin surface of the material. In this thesis we have studied the effect of differen LSP treatment parameters on entered residual stress on samples of Al alloys 2017A-T451 and 7075-T651. We have analized the impact of two different coatings (Al tape and black PVC tape), different power densities and also different numbers of passes. By using x-ray diffraction (XRD) method we have measured residual stresses on the treated surface and on the other/untreated side of the Al plates with 10mm thickness. The results of the analys have confirmed that largest residual stress has been entered using black PVC tape as coating, higher power density and larger number of laser beam passes across the surface. The highest compressive residual stresses were obtained using highest power density (8 GW/cm2), highest number of passes (3) and with the use of black PVC tape, where the compressive residual stresses in transversal direction were -420 MPa for 2017A-T451 and -421 MPa for 7075A-T651 Al alloy. The highest residual stresses on the untreated/opposite side were confirmed with alloy Al 7075A-T651, treated with the highest power density, highest number of passes and coated with black PVC tape.
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