Effects of La addition on the mechanical properties and thermal-resistant properties of Al–Mg–Si–Zr alloys based on AA 6201

In this paper, the influence of La addition on the aging behavior, microstructure, mechanical properties, and thermal-resistant properties of Al–Mg–Si–Zr aluminum alloy has been studied with the help of optical microscope (OM), Brinell hardness measurements and scanning electron microscopy (SEM) equipped with energy dispersive spectrum (EDS). The results show that La addition decreases the peak-aged hardness during aging process. Electrical conductivity and thermal-resistant properties improve when the La addition exceed 0.2%. Increasing La content to 0.3% leads to a poor elongation at fracture. Most of La element exists in the form of compounds containing Si which result in improvement in thermal-resistant properties. The tensile strength of the material with 0.2% La addition reduces while the thermal-resistant properties and electrical conductivity improve. This amount of La addition added to the experimental alloy could be a compromise between the mechanical properties and others like electrical conductivity and thermal-resistant properties.