The book presents physical ideas about the mechanism and kinetics of solid body sintering - the main process of the technology of cermet production and the production of refractory materials. The physics of sintering processes is presented as a branch of the physics of a real crystal, which studies the laws of mass transfer and porous structures. The new edition differs from the previous one in more complete involvement of ideas about the dislocation and dislocation-diffusion mechanism of mass transfer in porous defective structures, as well as about the transfer of matter by the mechanism of movement of macroscopic elements of the porous structure as a whole.