Microstructural characterisation of two phase materials

Abstract

Based on the concepts of contiguity and continuous volume, a number of topological parameters have been defined for characterising the microstructure of two phase materials. These parameters can be either determined experimentally using standard metallographic methods or calculated from the known grain sizes and volume fractions of the constituent phases assuming equiaxed grains and random phase distribution. The combination of such topological parameters offers an effective description of phase distribution in a two phase structure having any volume fraction, grain size, grain shape, and phase distribution. In addition, the concept of directional contiguity is introduced for the analysis of microstructures oriented along a particular direction. A topological transformation of two phase microstructures has been proposed, which allows a two phase microstructure having any volume fraction, grain size, grain shape, and phase distribution to be replaced by a ‘three element body’ with three microstructural elements which are aligned in parallel along a particular direction of interest. The transformed three element body is mechanically equivalent to the original microstructure along the aligned direction. MST/1844