Thermodynamic Theory of Sintering and Swelling

Abstract

The General Thermodynamic Theory of Sintering, formulated by the author in 1998 is given. This theory is applied to the problem of swelling of materials under conditions of radiation. Driving forces, caused by the presence of the evolution of heat in the volume of a sample (electric contact, hf, inductive heating or penetrating radiation, e.g., neutrons could be the sources of the heat in the bulk of a sample) are considered. The influence of these driving forces on sintering, structure and properties is discussed. The role of mobile and immobile dislocations, grain boundaries, and pores is regarded. Cycling and pulsing regimes of sintering are investigated. A mesoscopic approach, described in present paper, which had been used for years to solve sintering problems, also could help solving problems of nucleation, decomposition, and other problems in the theory of alloys. Described relaxation time technique could help simplifying calculations and give more clear physical picture. Bulks heating driving forces, important for small size objects of microelectronics or/and heat evolving elements in nuclear reactors, are important also for the problems of nucleation and decomposition in these objects.