PECULIARITIES AND ADVANTAGES OF STUDYING THE SURFACES OF SPACE TECHNIQUE MATERIALS BY ATOMIC FORCE MICROSCOPY

The article presents the advantages of the atomic force microscopy (AFM) method as one of the most versatile and promising methods for studying the surfaces of space engineering materials. A comparison of the results of the study of such materials using the example of aluminum nitride (AlN) by the methods of scanning electron microscopy (SEM) and AFM was carried out. As a result of the comparison, it was established that, despite the higher resolution of the SEM method, its main disadvantages are the impossibility of vertical scanning of surfaces and the lack of an opportunity to study their physical and mechanical properties. The main features of the process of studying the topography of surfaces using the AFM method have been established. They are the possibility of high-precision positioning of the measuring instrument (with the accuracy of determining a given area — up to 40 nm), elimination of distortion of the obtained image of the studied area, and automatic correction of the research speed. The arithmetic mean values of the micro-roughnesses of the aluminum nitride surfaces obtained by the AFM method were determined both for samples that were not exposed to extreme environmental conditions (Ra = 147 nm; Rq = 163 nm) and samples that were exposed to extreme environmental conditions for a long time (120...140 hours), which simulates space conditions (temperature 550 °С, pressure 6.8...7.2 μbar) (Ra = 381 nm; Rq = 422 nm). The maximum porosity in the surface layer (up to 1.5 μm) of aluminum nitride samples was also determined in the range of 3...5.2%.