Авіаційно-космічна техніка та технологія (Apr 2022)
Modeling of conditions for obtaining nanostructures in aluminum alloys under the action of ionizing radiation
Abstract
The use of laser radiation as a source of ionizing radiation to obtain nanostructured and submicrostructured layers on aluminum alloys requires the determination of the necessary technological parameters. Therefore, a theoretical study of ionizing radiation on aluminum alloy AK8 was conducted according to the previously proposed model. When choosing the region in the material of the aluminum alloy, where nanostructures can be formed under the action of ionizing radiation, apply different lengths of ions. Because of the theoretical study of the formation of nanostructures in the surface layer of the aluminum alloy AK8, the temperature distribution in the zone of ionizing radiation at different depths of the material was obtained. Temperature fields for different heat flux densities q1 = 106 W/m2 and q2 = 105 W/m2 were also constructed. The obtained temperature fields for heat flux q1 showed that with increasing depth of the material, the temperature decreases from 2480 to 650 K. The values of maximum temperatures on the material surface are slightly higher than necessary to obtain nanostructures at lower depths maximum temperatures decrease to nanostructures can be realized. Simultaneously, under the action of heat flux q2 = 105 W/m2, the maximum surface temperature decreased to values of 1950 K, and at depth it was 550 K. and was equal to 106 K/s at q2. All these confirmed the possibility of creating conditions for the formation of nanostructures. Due to the temperature range obtained from the calculated temperature fields, the depths of the aluminum alloy where nanostructures can be formed were determined. Studies of the effect of laser radiation spot size on the surface of the material on the formation of nanostructures were also conducted, which showed that when exposed to a spot size of 3 · 103 to 10-3 m, the possibility of nanostructures is significantly reduced, while reducing the spot size to 10-4 m leads to a significant increase in the possibility of forming nanostructures. To estimate the possible volume of nanostructures, the dependence of the nanocluster size on the heat flux density in the range from 107 to 1010 W / m2 and its action time in the range from 10-9 to 10-3 s were considered. The dependence of the maximum temperature on the heat flux density and the time of its action is also constructed. All this allows you to choose the technological parameters of laser radiation to obtain nanostructured layers on aluminum alloys, and the ability to determine the size of nanostructures allows you to predict the physical and mechanical characteristics of the surface layers of processing materials. These studies may be of interest to specialists in strengthening the surfaces of aluminum alloys and further studies of nanostructures.
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