Distribution of temperature, strain rate and strain in plastically deforming metals at high strain rates

Abstract

A method of calculating the distribution, and its time dependence, of temperature, strain rate and strain in plastically deforming metals is presented. It is assumed that the strain rate y depends on stress T and temperature T as γ = (const) T^m exp (-E/RT) where m, E and R are constants. It is found that the heat generated by deformation causes a significant inhomogeneous plastic deformation associated with the inhomogeneous temperature distribution in a specimen at high strain rates. The flow stress decrease arising from the inhomogeneous deformation is calculated; it is greater at lower temperatures, at higher strain rates and for longer specimens. The temperature rise in slip bands is also considered. Calculations are carried out for aluminium at temperatures above 100°C. Some of the results are compared with experimental observations.