The purpose of the master's thesis was to observe the effects of various heat treatment parameters i.e., time and temperature of solution annealing and artificial aging, on the development of microstructural components and the effect on the hardness of AlSi7Mg and AlSi7Mg alloys with Li addition. As a comparative sample, we observed the influence of the parameters on the AlSi7Mg alloy, which was exposed to the same heat treatment conditions as the AlSi7Mg alloy with Li addition. Samples of both alloys were cast in two measuring cells, a croning and a graphite measuring cell, representing two different cooling rates. In the first step, we prepared a melt of the AlSi7Mg alloy and an alloy of the same composition, to which we added 1 wt. % Li. In the case of croning measuring cells, equipped with a K-type thermocouple, we monitored the solidification with the help of a thermal analysis - ETA. Each alloy was solidified at two different cooling rates. We prepared a series of 24 samples where each alloy had 6 samples for the corresponding quench rate. The basic starting state were the samples in the cast state, and the other samples were then, according to the plan of heat treatment combinations, solution annealed at a temperature of 530 °C for a duration of 8 hours and/or artificially aged at a temperature of 160 °C for a duration of 4 and 8 hours. After finishing the heat treatment, we performed 6 hardness measurements for each sample according to the Vickers method. Using the results of thermal analysis and images of microstructures, we were able to prove the presence of individual phases and determine the course of solidification.
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