The Influence of Laser Surface Remelting on the Tribological Behavior of the ECAP-Processed AZ61 Mg Alloy and AZ61-Al₂O₃ Metal Matrix Composite

This paper deals with the tribological study of the laser remelted surfaces of the ECAP-processed AZ61 magnesium alloy and AZ61-Al₂O₃ metal matrix composite with 10 wt.% addition of Al₂O₃ nanoparticles. The study included the experimental optimization of the laser surface remelting conditions for the investigated materials by employing a 400 W continual wave fiber laser source. Tribological tests were performed in a conventional "ball-on-disc" configuration with a ceramic ZrO₂ ball under a 5 N normal load and a sliding speed of 100 mm/s. The results showed that both the incorporation of Al₂O₃ nanoparticles and the applied laser treatments led to recognizable improvements in the tribological properties of the studied AZ61-Al₂O₃ composites in comparison with the reference AZ61 alloy. Thus, the best improvement has been obtained for the laser modified AZ61-10 wt.% Al₂O₃ nanocomposite showing about a 48% decrease in the specific wear rate compared to the laser untreated AZ61 base material.