DEFORMATION OF BIMETALLIC WIRE DURING COMBINED ECAP-DRAWING

Abstract

In modern industry the most urgent problem is to increase the physical and mechanical properties of metal materials. One of the promising ways to improve such properties is to grind the elements of the grain structure to an ultrafine-grained (UFG) state. From all methods used to produce metal materials with ultrafine-grained structures, the most commonly severe plastic deformation (SPD) methods are used. Most of the currently existing methods of the SPD implementation have not been used in the real industrial sector due to the existing in this method of deformation of the disadvantage, which is the discreteness, i.e. the inability to process products of relatively long length and the need for a large number of processing cycles. And this determines the economic inexpediency of the introduction of this method in production. To solve these problems, technology of combined deformation “ECAP-drawing” have been developed. This work is aimed to investigation of bimetallic wire deformation during combined ECAP-drawing. Results of strain state study showed that layers of materials in the cross-section of wire have received different values of strain. Stress state of both materials is various in both deformation zones - in the ECAP matrix deformation area is divided for two sections (tension and compression) separated by diagonal. At all deformation stages the level of compressive stresses is much higher of tensile stresses.