Methods and results of studying the Portevin - Le Chatelier effect: experiments and macrophenomenological models

Discovered in the first half of the 19th century by F. Savard and A. Masson (and rediscovered at the beginning of the 20th century by A. Portevin and F. Le Chatelier), the effect of discontinuous plasticity remains the subject of intensive experimental and theoretical research to this day. To a large extent, the interest in this problem is due to its significance. It is known that intermittent plasticity (the Portevin-Le Chatelier (PLC) effect), especially at the final stages of processing metals and alloys by plastic deformation, leads to a decrease in viscosity, a significant increase in roughness of product surfaces. The latter reduces static and fatigue strength, corrosion resistance, weakens aerodynamic characteristics, and wear resistance. On the other hand, with the development of experimental technology and theoretical methods, more and more new mechanisms are revealed that cause discontinuous plasticity, the study and description of which is a huge area in breadth and depth for fundamental research by experts in mechanics, physics, and metallurgy. The paper contains two main parts. The first of them provides an overview of numerous experimental studies of alloys’ behavior in the temperature and strain rate ranges characteristic of the manifestation of PLC effect. The features and main mechanisms of the effect realization for various alloys are considered. The second part of the paper contains a description of phenomenological constitutive models based mainly on experimental studies of the behavior of macrosamples (as a rule, under uniaxial loading). In a number of these models, considerations of a physical nature were used for the formulation. In conclusion, a brief summary of the review papers is given. Constitutive models based on the consideration of physical mechanisms and their carriers (dislocations, impurity atoms) are contained in a separate review prepared by the authors.