Gangalo O. Theory developing and technology improving for the equal-channel angular pressing of copper and aluminum billets.

The objects of research are processes of equal-channel angular pressing, including the angular hydropressing and double equal-channel side pressing. The goal of research is to develop the theory of equal-channel angular pressing, accounting the complex influence of the die geometry, the strain hardening, friction conditions on process parameters booth with improving of submicrocrystalline copper and aluminum rods manufacturing technology using the combined application of angular and direct hydropressing instead of traditional ECAP method. Methods of research. The analysis of intensive plastic deformation processes was made in accordance with main provisions of the metals processing by pressure theory. The methods of power balance, the upper assessment and computer simulation (finite element method) was used. Experimental investigations of the processes of plastic deformation were performed in laboratory conditions with the use of experimental devices on universal presses. Parameters of process were recorded using the methods of strain-gauging (tensometria). The investigations of structure were performed using the methods of optical and electron microscopy. The mechanical properties were defined using methods of hardness and microhardness measurement, and tests for stretching and draught. For techniques of processing metals by pressure modeling and statistical examination of experimental data the PC was used. Results. The development of upper bound solution concept for equal channel angular pressing pressures with die rounded outer corner and without the same was found that is based on complex accounting for the die geometry, the materials strain-hardening and the friction condition effects. The procedure of the die geometry and the friction factor influence on strain rates distribution of perfectly plastic and strain-hardened materials was discovered.