Drawing with Thinning under Viscoplasticity Deformation of the Anisotropic Material

Abstract

The paper considers the drawing process with wall thinning of the anisotropic workpieces made of high-strength materials exposed to viscoplasticity deformation. Scientific literature is paying insufficient attention to calculation of the deformation processes of workpieces exposed to viscoplasticity. Relationships are proposed to determine stresses and continuity of the workpiece material during drawing in heating the cylindrical products with a thinned wall. State of hot material viscoplasticity is accepted under the plane deformation scheme. Equilibrium equation, yield condition for anisotropic material and discontinuity kinetics equations were used making it possible to predict strength characteristics and accuracy of the products obtained. Calculations of the drawing process modes for workpieces made of the AMg6 aluminum alloy and of the VT6s titanium alloy were performed. Graphic dependences are demonstrated of alterations in the operation specific force and in the material continuity value on the motion speed of the deforming punch. At the given forming temperatures, the energy continuity equation corresponds to the aluminum alloy, and the deformation equation corresponds to the titanium alloy. Influence of the workpiece mechanical properties anisotropy on the drawing technological conditions was studied. It is shown that force modes and continuity alteration of the deformed material depend on the anisotropy coefficient at a given temperature. This factor is determined by strain strengthening of the workpiece material and softening over time