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В работе систематически исследовано влияние горячей деформации кручением под квазигидростатическим давлением на фазовый состав и базисную текстуру ВТСП керамики Bi(Pb)2223. Обнаружен узкий температурный интервал T д =863-867 o C, в котором острая текстура с фактором ориентации базисных плоскостей на уровне F=0,996-0,997 формируется при сравнительно малых углах кручения (около 10°). С помощью энергодисперсионного анализа и рентгеновской дифракции установлено изменение соотношения фаз в зависимости от температуры, угла кручения и участка образца. Обнаружена корреляция объемной доли и среднего размера частиц вторичных фаз со степенью базисной текстуры.

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In this paper, computer simulation of the friction stir welding (FSW) of AlMg6Mn0.6 aluminum alloy sheet blanks by means of the DEFORM-3D software package is carried out to select the optimum pin geometry based on the calculation of the displacement and speed of displacement of the material points. Pins in the shape of a cylinder and a truncated cone with the cone angles of α =10, 20, and 30° were considered. The friction coefficient of 0.5 was assumed. Instrumental steel AISI-D2 was chosen as the material for the tool. To reduce the computation time and avoid the instability of solution, the model of welded blanks was built as a single body of 3 mm thickness and 40 and 30 mm length and width, respectively. The behavior of the AlMg6Mn0.6 alloy was described using the Johnson-Cook model. The FSW process was simulated at the tool moving speed v = 2 mm / s, rotation frequency ω =1000 rpm and axial force P = 25 kN. The initial temperature of the workpiece and the tool was 20°C. When welding the blanks, the conditions of heat exchange with the environment were set. The simulation results solution have shown that the flow of the material of the workpiece depends on the shape of the pin and is different over the thickness of the workpiece. The material in the lower area of the workpiece is practically not subjected to mixing for all values of the cone angle of the pin, in contrast to the middle and upper areas of the workpiece, where the material is noticeably mixed. Of all the tips considered, the most preferred for the FSW is a pin in the form of a truncated cone with the cone angle of 10°, since it provides good mixing in the plane of the workpiece, the maximum displacement of the material towards the root of the weld, and also allows one to get the most symmetrical seam.

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