Numerical observations of scaling laws in the consolidation of powder compacts

Powder consolidation under load is a common means of forming ceramic or intermetallic components for advanced structural applications. Micrometer/nanometer-sized powders are being used as a means for creating new composite microstructures on a fine scale. In addition, powders of this size provide advantages, in general, for powder processing in terms of reduced processing pressures/temperatures and additional control over the final microstructure. However, current models of the deformation processes in powders do not adequately represent the experimental observations in micrometer/nanometer-sized powder compacts. In this paper, a constitutive model for the consolidation of these powders is proposed. The mechanisms considered include elasticity of the aggregate, diffusion along the interparticle contact area, and relative slip between the particles. The finite element method is used to predict the deformation of a powder compact for a range of loading conditions. A cubic array of cylinders is used to model the compact in a two-dimensional (2D) plane strain situation. Unit cell calculations are performed and scaling laws for the macroscopic response during the deformation of the powder aggregate are detected in the numerical results.