Physical concept of shear fracture mesomechanism and its applications

Abstract

The key objective of the present paper is an attempt to create an interface between the existing inconsistent views on the microscopic and macroscopic aspects of the mechanism of plastic deformation and shear fracture. This will be enabled by a focus on the course and effects of the evolution of dislocation structure, and will consist in considering an indirect, i.e. a mesoscopic scale of the discussed phenomena. Thanks to this, a synergy between the mechanisms of deformation and fracture of materials will be proven, which will provide an opportunity for a smooth transfer from the microscopic, through mesoscopic, to macroscopic scale of the analysed phenomena. This in turn will offer an opportunity to define and use the new criteria for controlling the mechanism of shear fracture. These criteria will be applicable to the complete range of temperatures and strain rates which are typical of metal working processes. Some examples of how these criteria may be applied in order to optimise the parameters of metal working will also be provided. These examples have made it possible to prove that the physical approach to shear fracture mesomechanism offers much broader cognitive and utilitarian opportunities than the existing purely mathematical methods. This is due to the fact that the physical approach allows for a deeper understanding of shear fracture meso- and macromechanism, and generates new criteria controlling this mechanism.