Densification of a viscous porous solid during dynamic pressing

Conclusions

• 1. An analysis is made of the densification of a viscous porous solid during dynamic pressing; it is shown that the application of a dynamic load (impact) to a porous solid densities the latter at a volume deformation rate which decreases as a function of time until a certain limiting value of density is reached corresponding to the instant when the rate falls to zero. The limiting change in the density function grows with increase in impact parameters and in the flowability of the solid phase of the porous solid.

• 2. In the dynamic hot pressing of a porous solid whose solid phase undergoes deformation obeying a nonlinear law$(\mathop \varepsilon \limits^ \circ \sim \sigma ^n )$, densification conditions are better than those obtained in the pressing of a porous Newtonian solid.

• 3. With increase in the value of the exponent in the equation describing a nonlinear relationship between the rate of deformation and the stress in the solid phase of a porous solid, the effect of temperature upon the densification of the solid during dynamic pressing diminishes, since$\sqrt[n]{B} \sim \exp \left[ { - \frac{{U(\sigma )}}{{nkT}}} \right]$.