A Classification of flow-Stress Anomalies, and the Specific Role of Strain Rate Sensitivity

Abstract

We propose a classification of stress anomaly mechanisms based on two limiting cases, according whether the macroscopic behaviour directly reflects the individual dislocation properties, or involves the whole dislocation population. We show that, in the second case, some typical anomalies can be defined according to the relative efficiencies of mechanisms responsible for an increase or a decrease of the mobile dislocation density, and are associated with specific strain rate sensitivities. The way in which such an analysis can help in deciding which models are most relevant is discussed.