This paper reports on the treatment of different Al-Si alloys after laser surface remelting through analysis of the changes in microstructure and hardness of a modified surface layer. On as cast samples, laser remelting of the thin surface layer was carried out with different energy inputs into the sample surface. The remelting conditions were varied by application of different lase beam power, different degrees of defocusing and different laser beam travel speeds across the sample surface. With the selected remelting conditions for the thin surface layer a sufficiently high energy input into the surface of individual samples was ensured. It varied between 165 and 477 J/mm2. After solidification of the surface remelted layer a fine-grained microstructure was formed. Such a microstructure was found to increase the hardness of the Al-Si alloys by 20 to 50%. The variation and sizeof the residual stresses greatly depend on the coolings rates determined by the laser travel speeds.
COBISS.SI-ID: 11872539