Investigation of the influence of laser treatment parameters on the properties of the surface layer of aluminum alloys

AbstractAn analysis of the literature concerning the methods of surface treatment of aluminum alloys has been performed. Based on the literature and on earlier initial investigation (hardness measurements, microscopic inspection, roughness measurements, tribological tests and scanning microscope inspection of AlSi6Cu4 and 6082 (PA4) alloy samples exposed to laser, it has been determined that the hardness of the AlSi6Cu4 alloy has increased from the level of 60–80 HV 0.1 to the level of 120HV 0.5 due to laser treatment, while heat treatment dispersion hardening has resulted in further increase of the hardness of the laser treated zones up to the level of 160 HV. The even structure obtained allows us to propose such technology for increasing hardness and wear resistance of those alloys. In the 6082 alloy, containing less alloy elements, the hardness increase is smaller reaching the level of 120 HV 0.5. This is related to obtaining zones with dispersion secretions. The suggested laser treatment parameters, 400 W and 530 W with the traverse velocity of 2.8 to 5.33 mm/s do not cause significant increase of roughness, due to which such surface does not require further machining. The results of initial tribological investigation are very promising and they allow us to expect that the technology of structure comminution by laser treatment will allow for improving the life time of products with laser treated surface