HPDL laser alloying of heat treated Al-Si-Cu alloy

Purpose: There are presented in this paper the investigation results of microstructure of the cast aluminium alloys in the as cast state as well after laser treatment used for alloying with carbide and oxide ceramic powders like aluminium oxide and silicon carbide, titanium carbide, vanadium carbide and tungsten carbide. The purpose of this work was also to determine the laser treatment conditions for surface hardening of the investigation alloys, like laser power, as well the laser scan rate. Design/methodology/approach: The investigations were performed using light and electron microscopy for the microstructure determination. By mind of the transmission electron microscopy, especially selected area diffraction method appliance it was possible to determine the phases occurred in the alloy in the as cast state. The morphology and size of the Mg2Si was also possible to determine as well the lattice parameters for this phase. Findings: Concerning the laser treatment conditions for surface hardening the scan rat as well as the laser power influence was studied. It was used a power in the range between 1.0 and 2.0 kW The structure of the surface laser tray changes in a way, that there are very high roughness of the surface zone and the flatness or geometry changes in an important manner, crucial for further investigation. Research limitations/implications: The aluminium samples were examined metallographically using optical microscope with different image techniques as well as transmission electron microscope. Practical implications: Developing of new technology with appliance of Al alloys, High Power Diode Laser and diverse ceramic powders can be possible to obtain, based in findings from this research project. Some other investigation should be performed in the future, but the knowledge found in this research concerning the proper process parameters for each type of alloy shows an interesting investigation direction. Originality/value: The combination of metallographic investigation for cast aluminium alloys - including electron microscope investigation - and HPDL treatment parameters makes the investigation very attractive for automobile, aviation industry, and others where aluminium alloys plays an important role.