Effect of Li additions and holding time on the mechanical properties of the AlSiM9mg alloys

Aluminum alloys are widely used in industry due to their lightness and ease of machining. Concurrently, the mechanical properties of aluminum alloys can be increased by different development studies. Grain refining, modification and heat treatment can be given as examples of these development studies. In this study, the influences that may occur in mechanical properties by adding lithium (Li) additions, which are generally used for lightening in aviation applications, to AlSi9Mg alloy at different levels have been investigated. Due to the slag problems especially at high Li ratios, a study with relatively low Li addition ratios has been developed. At the same time, the effect of Li additions on high temperature and holding times was also studied. According to the results of the study, it was observed that a high amount of slag was formed at the high Li addition level and the mechanical properties were in a decreasing trend. In addition, it has been observed that the increase in Li level negatively affects the fluidity. It was also observed that the holding times dramatically decreased the Li values in the aluminum alloy structure, this decrease occurred in the ultimate tensile strength (UTS) and yield strength (YS), while the unit elongation (%) increased slightly.