Laser surface remelting of Al-Mg and Al-Si-Mg alloys: microstructure and properties

Solidification is one of the most widely used manufacturing processes for metallic components.In the context of surface treatments, localized melting and resolidification represent an important application that deserves special attention.Among these, the Laser Surface Remelting (LSR) process is notable for creating a thin molten layer on the alloy surface.This occurs through the application of a continuous high-energy-density laser beam.Once the laser is removed, rapid solidification of the molten region is achieved by heat extraction into the remaining cold part of the material (the substrate), which has a much larger mass.Currently, there is great interest in new aluminum (Al) and magnesium (Mg) alloys for lightweight components such as pistons, manifolds, reducers, oil pans, and chassis, as well as in their laser treatments.Although LSR of Al-Cu alloys is well understood, there is a gap in studies on AlSi10Mg and Al-Mg alloys, which have high application potential.This short review addresses LSR applied to these less-explored alloys.Methods for determining cooling rates and their correlation with the resulting laser-modified microstructures will be presented.This study investigates the influence of laser surface remelting on the microstructure and mechanical properties of Al-Si10MgNi and Al-Mg-Sc alloys.The aim is to understand how alloy composition and laser parameters affect solidification features and their correlation with nanohardness and wear behavior.The results indicate that increasing Ni content (from 1Ni to 3Ni) in Al-Si10Mg alloys refines the microstructure and develops a third phase (Al 3 Ni), which increases the hardness.In Al-Mg-Sc alloys, higher Mg levels and slower scanning speeds promote cellular coarsening and affect hardness distribution across the laser melt pool.