Identifying regularities of high temperature on constant and variable fatigue life of AA7075-Al2O3 nanocomposite fabricated by stir casting method

Abstract

This study aims to determine the effect of high temperature on the fatigue life of AA7075-Al2O3 nanocomposites (6 wt % Al2O3) fabricated by stir casting. The research problem is to determine the durability, fatigue resistance, and mechanical properties of the nanocomposite under constant and variable loading conditions at elevated temperatures, as well as to identify changes in its behavior due to exposure to high temperatures. The results show that higher temperatures have a big effect on the nanocomposite's fatigue performance under both loading conditions. When the material was tested at a high temperature (150 °C) with an extra 6 wt % Al2O3, the ultimate tensile strength and yield stress both went up by 16 % and 15.7 %, respectively. Its fatigue life was also successfully tested under both variable and constant amplitude load conditions. The interpretation of the results suggests that the changes in the microstructure of the nanocomposite material at elevated temperatures lead to an increase in dislocation density and grain size, resulting in an improvement in its mechanical properties. The findings can be utilized to optimize the nanocomposite fabrication process and enhance its fatigue resistance at high temperatures. In addition, the results can be used to enhance the design of aerospace components and high-temperature engines that require materials with excellent fatigue resistance at elevated temperatures. In summary, the investigation of the effect of high temperature on the constant and variable fatigue lives of AA7075-Al2O3 nanocomposite provides valuable insight into the material's mechanical properties. The findings contribute to the development of materials that can withstand high-temperature conditions, which has implications for a variety of industries.