Abstract:
Description of the multilevel behavior of powder mixtures as heterogeneous media during sintering is the only approach to understanding of regularities in volume changes in a two-component powder body as a result of high-temperature heating. In the framework of prevailing models, the role of heterodiffusion during the growth and densification of powder bodies as a result of sintering remains unclear. Consequently, it is very important to construct a physical model that, on the one hand, would reflect the actual structure of the body being sintered to the maximum possible extent and, on the other hand, would adequately describe the regularities of its behavior during sintering. A multiparticle model of a powder body consisting of a binary mixture is considered on a mesoscopic level; this model also takes into account the features of diffusion processes at the microscopic level. The model provides an adequate qualitative description for the observed concentration dependences of powder body densification during solid-phase sintering and both qualitative and quantitative description in the case of liquid-phase sintering.