Structure-property relations in duplex materials

A two-dimensional micromechanical model to determine the plastic flow properties of two phase alloys with coarse microstructures is presented. In the analysis special attention is devoted to the correct representation of the geometrical features of the real microstructure in the model. The model microstructures are characterized by stereological parameters also applied to real materials. Microstructures are of inclusion-matrix topology at low and high volume fractions of the second phase. At intermediate volume fractions duplex-microstructures are formed. The calculation of the plastic flow properties of a solid consisting of two elastic-perfectly plastic constituents is conveniently done by a unit cell approach with the finite element method. The limit flow stress of the composite is calculated for microstructures covering the whole range of possible volume fractions. The incorporation of the microstructural informations in the analysis of the computed results leads to an improved understanding of the plastic flow properties of the model composite. Results from the present model calculations are compared to results obtained from other micromechanical models.