Application Analysis of Electron Microscope in Aluminum Alloy Materials
In this paper, the principles of transmission electron microscopy and scanning electron microscopy, sample preparation methods and so on were introduced respectively. The application of transmission electron microscopy and scanning electron microscopy in the research of aluminum alloy materials were expounded in depth by taking the analysis of microstructure characteristics of 7055 aluminum alloy sheet with 5 mm thickness and aging as an example. Meanwhile, the evolution of intragranular precipitation and grain boundary precipitation behavior and the evolution of tensile fracture morphology of 7055 aluminum alloy sheet under different aging conditions were studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results showed that the size of precipitated phases was small and the precipitated phases at grain boundaries were continuously distributed in the under-aged state (120℃/3h) and peak-aged state (120℃/24h) of 7055 aluminium alloy, and the fracture features were the mixed morphology of a small number of dimples and intergranular fracture, while the precipitated phases in the over-aged state (120℃/36h) were coarse and the precipitated phases at grain boundaries were present. The fracture features were mainly dimples. Microstructure observation under electron microscopy can reveal the evolution law of its properties.