Microstructure Evolution of 2024 Aluminum Alloys Subjected to Thermal Cycling in Simulated LEO Space Environment

The microstructures and properties of 2024 aeronautical aluminum alloy subjected to thermal cycling were investigated in simulated Low Earth Orbit space environment. The experimental results demonstrate that the microhardness of aluminum alloys changed with the increasing of thermal cycles. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) show that the property changes of the 2024 aluminum alloys during the thermal cycling period are closely related to the microstructural evolution. The relationship between the microstructural evolution and the thermal fatigue was also discussed.