Impact of aging time on the morphological, mechanical, and tribological behavior of Al-6.6Si-0.2Mg-0.2La hypoeutectic alloy

Abstract

The present work aimed to examine the influence of Lanthanum (La) on the morphological, mechanical, and tribological characteristics of Al-6.6Si-0.2Mg alloy. The alloy specimens were exposed to an aging process at 180°C for 8h and 12h. The morphological transformation due to La addition was analysed with an emphasis on altering primary and eutectic silicon morphology, grain refinement, and intermetallic phase distribution. The experimental investigations were carried out using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) whereas the hardness and wear characteristics were analyzed by performing Vickers microhardness and pin-on-disc tests. The obtained results demonstrated that lanthanum inclusion causes significant microstructure refinement, resulting in enhancing the microhardness by up to 60 %, proliferating the tensile characteristics by 70%, and aiding in improving the tribological characteristics of the Al-Si-Mg alloy. The results provide a clearer understanding of the alloy modification process and offer valuable insights for enhancing the performance of Al-Si-Mg aluminium alloys in automotive and aerospace applications.