A model of sintering for materials with bimodal pore distribution is formulated as a generalization of the continuum isotropic theory of sintering. In contrast to known models that only contain one behavioral parameter, i.e. porosity, the model suggested is described by two parameters for each type of pore. The evolution equations for each type of pore as well as the effective viscosity coefficients and Laplace pressure (sintering potential) are determined by unit cell analysis.

A new multi‐scale numerical approach for the modeling of sintering of macroscopically inhomogeneous materials is put forward. The new approach does not require the formulation of material constitutive equations: it specifies material properties through the definition of macroscopic unit cells. As a result, the influence of any number of material structure parameters on sintering kinetics and on specimen distortion can be investigated. The method is based on the consideration of the sintered body macroscopic behavior in parallel with an online analysis of the mesoscopic evolution of the unit cell structure. The developed modeling approach provides the information on the sintering progress at both macro‐ and meso‐scale levels. The examples of diffusion sintering of ceramic composites and of viscous sintering of a bi‐layer porous specimen containing voids of anisotropic shapes are considered.

621.762A study has been made on the effects of loading scheme and conditions restricting macroscopic strain on the work-hardening kinetics and strain accumulation in the solid state in sintering materials with bimodal pore size distributions. Active loading intensifies the reduction in the small pores. The greatest effect comes from combining sintering with hydrostatic compression. At the same time, kinematic constraints (partial or complete adhesion in surfaces) substantially retards the shrinkage of large pores, which means that the porous structure can be controlled.