Mathematical modelling of plastic deformation processes of bimetallic tubes with porous-internal layer in conical dies

The present paper deals with the mathematical analysis of the extrusion of bimetallic tubes, made of porous materials. The Plasticity Theory of Real Porous Materials [G.L. Petrossian, Plastic Deformation of Powder Materials, Metallurgy, Moscow, 1988] is used for the establishment of real regularities of bimetal's plastic deformation and development of traditional technological schemes of its treatment. An algorithm and a computer program were composed to integrate the derived system of differential equations. The model created allows revealing the influence of initial porosity, applied loading, level of deformation, materials hardening and other technological parameters on the stress-strain state of the process. On the basis of numerical results obtained, graphs between components of stress-strain state of bimetal and porosity of internal layer are drawn, which allow solving important technological problems.