Computer Simulation of the Direct Pressing Process Through Various Matrix Funnel Profiles

Abstract

The stressed and deformed state of the metal and the dimensions of the center of deformation during pressing depend significantly on the design of the tool and, in particular, on the shape of the matrix funnel. However, there is still no single point of view on the influence of the geometry of the deformation center on the energy forces of the metal pressing process. Based on the analysis of the field of slip lines of the steady-state stage of pressing through a symmetric single-point matrix, it is proposed to use the profile of the matrix funnel made along the slip line separating the elastic and plastic zones. The following types of matrix funnel profiles were investigated using computer simulation of direct extrusion of lead samples with a drawing value 81 at a speed of 1 mm/s: cycloid concave; convex; the second convex, which is built on the logarithmic dependence; conical and concave, which is built along a sliding line that separates the elastic zones from the plastic in the pressing process. The results of theoretical studies, computer simulations of the direct pressing process using the Deform 2D/3D software package, and experimental experiments have shown that optimal energy-power conditions are achieved by pressing through a matrix that has a profile made along the slip line. The results of the experimental study of the kinetics of the flow of the discrete medium showed that the shape of the matrix funnel influences the size of the deformation center and the distribution of the resulting deformation in the molding. From the analysis of deformation of the granules, it is determined that the concave funnel, built along the slip line, is characterized by a curvature of the axisymmetric particles in the direction of deformation. These curvatures decrease as the granules move to the axis of symmetry of the matrix. It is noted that for a convex funnel, the length of the deformation center is greatest; for a conical metal flow is close to the radial in the direction of the truncated cones.