Modelling the temperature rise effect through high-pressure torsion

Abstract

An approach composed of the thermodynamics-based dislocation model and the Taylor theory is used to investigate the evolution of microstructure and flow stress during high-pressure torsion (HPT). The incremental temperature rise is considered through the modelling of HPT. The temperature can affect the annihilation of dislocations and thus the dislocation density. The model predicts the dislocation density, sub-grain size and flow stress during HPT. The modelling results are compared with the experimental data and the modelling results without considering the incremental temperature rise. A remarkable agreement is observed between the modelling results with considering the temperature rise effect and the experimental data.

Finite Element Modelling of High-Pressure Torsion: An Overview

“…Nevertheless, a more recent study revealed that more accurate estimations for these parameters may be obtained by considering the temperature rise in HPT discs in the proposed model. 76) Further accomplishments in FEM modelling of HPT processing include models for the establishment of flow vortices in HPT-processed composites, 77) predictions of the evolution of texture in FCC metals, 42) simulations showing the influence of formation of anisotropic lamellar structure in pearlitic steel 78) and the development of an iterative model to measure stress-strain curves based on torque measurements during processing of disc-shaped samples using anvils having either constrained or unconstrained configurations. 43,44) It has been consistently shown throughout the numerous investigations summarised in this overview that the finite element method is recognized as an important mathematical tool capable of providing a better understanding concerning the flow behaviour and the microstructural evolution during HPT processing.…”