Modelling hot deformation behaviour based on evolution of dislocation substructures

摘要

In this paper, hot worked dislocationsubstructure is described in terms of differentialevolution of three internal state variables:internal dislocation desity, subgrain size andmisorientation between subgrains. The equationshave been applied to the hot deformation of an Al-1%Mg alloy during constant, increasing anddecreasing strain-rate tests. In all cases theflow stress is controlled by the instantaneousvalue of the Zener-Hollomon parameter, but astransients of dislocation substructure occur whenthe strain-rate is decreased, it is inferred thatthere is a compensating transient in the friction stress.