Structure and properties of ultra fine grained aluminium alloys after laser surface treatment

The presented investigation results concern the influence of laser heat treatment on the structure and properties of aluminium alloys that underwent severe plastic deformation using the equal channel angular pressing method. The initial stage of this study aimed at determining the possibility of improving the mechanical properties of core material using the severe plastic deformation process method and the subsequent partial recrystallization process that allows obtaining equivalent ductility and grain refinement. The next stage involving investigating the surface modification of the fine grained alloy by remelting and feeding silicon carbide powder into the molten material and to end solidification. To modify the surface layer of aluminium alloy, the Ytterbium Laser System YLS-4000 has been used, with the applied power of the laser beam in the range of 1.2 kW and 2.0 kW. The linear laser scan rate was 0.4 m/min. Results of the conducted treatments a core material with better mechanical properties, in comparison to initial state, was obtained whereas laser surface treatment allows to obtain composite surface with increased hardness and enhanced wear resistance when compared to substrate material.