Simulation of the Densification Dynamics of Cu + Al₂O₃ Powder Mixture under Dynamic Hot Pressing

Abstract

The densification dynamics of a Cu + Al₂O₃ powder mixture under dynamic hot pressing is simulated using a third-order dynamic system. The computer simulation has resulted in a data array showing the time dependence of the force induced by mechanical interaction of the impact machine working tool with the heated porous preforms, time variation of density, mean-square-root strain rates and stresses in the matrix that forms the porous body. The plotted phase trajectory of dynamical system from the beginning of preforms densification to impact tool elastic recoil is characteristic of impact dynamics. The mechanothermal effect generated under volume viscous flow and manifested itself as the increase in the temperature of the porous body is determined. It is established that the shear viscosity of the porous body shows a stronger dependence on the initial impact velocity in comparison with the heating temperature. The activation energy for the matrix viscous flow is equal to 0.266 eV.