Hot Deformation of Alloys: Characteristic Structural and Mechanical Properties and Constitutive Equations Used for Modeling of the Technological Processes

Abstract

A brief overview on the hot deformation of alloys applied to the hot working problems is provided. The analysis of the typical stress-strain diagram shows that at high temperature many alloys exhibits softening during active deformation. There is a significant difference between the behaviour of alloys under optimal conditions of superplasticity and under conditions where one or more parameters lie beyond the optimal limits. Herein, we present two approaches to the modelling of microstructure evolution - uncoupled and coupled. In the first case, the boundary-value mechanical problem is solved separately and obtained data is used as the input for the microstructural modelling. In the second case, transformation of the microstructure is directly involved in the constitutive relations via internal variables andthe coupled system of equations. Some approaches to the construction of the coupled models are discussed. The importance of classification of deformation processes on the basis of the thermomechanical loading history is noted.

Keywords

• alloy
• hot deformation
• superplasticity
• microstructure
• constitutive equations
• modeling
• workflow