SCIENTIFIC APPROACHES TO PROBLEMS OF MIXTURES SINTERING

摘要

The existing theories cannot convincingly explain relationships observed during sintering of mixtures and do not always help to solve practical problems of sintering metal materials and ceramics. The main weakness of the known theories are insufficient attention to the phenomenon of alloy formation and its affect on volume changes of compacts, faulty ideas regarding driving forces for the sintering process, the mistaken mechanism of dissolution of solid phase in liquid, and the inaccurate mechanisms of growth and densification during the sintering of mixtures. Besides, the obsolete theories are developed, as a rule, on the basis of a two-partial model that does not permit to take into account the skeleton structure of a powder body and the presence of interparticle pores in it. Essentially fresh concepts in the theory of mixture sintering are formulated and grounded in this paper. The new approaches eliminate the drawbacks and discrepancies in the existing theories and provide the scientific basis for solid state and liquid phase sintering of mixtures.