Shear and compressive rheology of aggregated alumina suspensions

The shear and compressive properties of aggregated alumina particles are determined as functions of volume fraction and the strength of the interparticle attraction. Over a range of volume fractions, yield stresses, tau(y), elastic moduli, the strain delimiting the extent of the linear elastic response, and compressive yield stress, P-y, are well described by power-law functions of volume fraction, while the role of interparticle attractions can be accounted for by expressing these mechanical properties as (phi/phi(g) - 1)(n), where phi(g) captures the strength of particle attractions and n the microstructure. The links between compressive and shear properties are well described by linear elastic models where the P-y and tau(y) are a function of Poisson's ratio which, for the suspensions investigated has a value near 0.49.