Determining of laser surface treatment parameters used for light metal alloying with ceramic powders

There are presented in this paper the investigation results of microstructure as well hardness investigation of the surface layer of cast aluminium alloys in as‐cast state and after laser surface treatment using a high power diode laser (HPDL) with Al₂O₃ ceramic powder. The purpose of this work was to determine the proper laser treatment conditions for surface treatment of the investigated alloys and to describe the structural changes occurred in the surface layer after laser treatment. For investigation of the obtained structure there was used light as well scanning and transmission electron microscopy. The morphology and size of the ceramic powder particles as well the structure of the remelted aluminium surface layer was possible to determine. After the laser surface treatment carried out on the aluminium cast alloys there are visible structural changes concerning the microstructure as well as distribution and morphology of the fed particles occurred in the sample surface. Concerning the laser treatment conditions for surface hardening also the laser power and ceramic powder feed rate was studied. The structure of the surface laser tray changes in a way, that there are zones detected like the remelting zone and the heat influence zone. This investigation with appliance of a high power diode laser for Al alloys makes it possible to obtain or develop an interesting technology very attractive for different industry branches.