A first report on deformation-mechanism maps

Abstract This report introduces the idea of deformations-mechanism maps: maps which display the fields of stress and temperature in which a particular mechanism of plastic flow is dominant. Most materials have the capacity to deform by several alternative and independent mechanisms: dislocation glide, diffusional flow and dislocation creep are examples. Each appears on the map as a field. A point on a map then identifies the dominant mechanism and indicates the resulting strain-rate. Three applications of the maps are discussed. First, they permit a study of the effect of crystal structure and atomic bonding on plastic flow. Second, they help in the design of experiments to study a given flow mechanism and in locating, identifying and characterizing missing mechanisms. And, third, they are useful in a qualitative way for choosing a material for engineering applications, for predicting the mechanism by which it deforms and hence in selecting, or predicting the effects, of strengthening mechanisms.