Plasticity in casting - Hot metals | Techniques de l'Ingénieur

Overview

ABSTRACT

This article is dedicated to the viscoplastic behavior of hot metals. The sensitivity of the constraint of plastic flow, the deformation velocity and sensitivity to temperature. Thermal phenomena, be they transfers or dissipation of energy, evidently play a considerable part in deformations and stresses metals are subjected to (dilatation, contraction, change in structure). To sum up, the approach of the behavior of hot casting inevitably includes the formulation of the viscoplastic behavior and at hot friction as well as thermal evolution and thermomechanical coupling.

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AUTHOR

Eric FELDER : Ingénieur civil des Mines de Paris, Doctor of Science - Senior Researcher at the Centre de mise en forme des matériaux (CEMEF) - École des Mines de Paris, CNRS Sophia-Antipolis

INTRODUCTION

The aim of this section is to take more realistic account of the hot metal behavior described in the [42] file: sensitivity of plastic flow stress to strain rate and temperature.

In addition, it is important to take into account thermal phenomena (energy transfer and dissipation) that condition the metal's temperature, behavior, deformation and stresses: rheology, expansion or contraction, structural change. Compared with the [16] file, we will therefore abandon assumptions 4 and 5 and the E∞ hypothesis.

You'll find a table of notations and symbols at the end of the file.

Behavior in hot forming includes :

formulation of viscoplastic behavior and hot friction ;
calculating the temperature field T and thermomechanical couplings ;
presentation of the principles of thermomechanical metallurgy for analyzing the deformation, stress field and structure of metal during cooling after hot forming, a problem similar to that of its evolution during heat treatment [79] and welding operations [80] .