Mikhailov O. Control of powder consolidation and forming of porous blanks by computer modeling of plastic behavior of porous bodies

Thesis is devoted to the development of new approaches for the control of mechanical and other service characteristics of powder-based components during their pressing and forming by control of porosity and accumulated strain volume distributions. The main method of investigation is computer modeling of pressing and forming based on continuum rheological model of plasticity of porous bodies and numerical finite element approach. New model of plastic deformation of porous bodies has been put forward in the Thesis and numerical finite element approach for its implementation has been developed. The model takes into account the degree of powder deformability. For the modeling of consolidation of bi-porous and multi-components powder systems, new numerical approach combining finite-element and discrete modeling has been developed. Thesis is aimed at analysis of powder pressing, die forming, forging and extrusion of porous blanks with special attention on forming methods using intense shear loading. Qualitative explanation of pressing crack development in rigid dies has been proposed and analysis of radial flow during different types of pressing has been carried out. Special features of pressing of bi-porous and multi-component powder systems have been investigated. In this case powder behavior is modeled on the two structure levels: the level of powder particles and the macroscopic level of powder body. Results of the Thesis found industrial applications in the development of new powder consolidation technological processes.