Solid state spreading in the Cu/Cu system

Solid state spreading of copper particles on a copper polycrystalline substrate was analysed at 1050∘C. A specific procedure was settled to produce pure monocrystalline and nearly spherical copper particles. Spreading dynamics were analysed from SEM images and preferential particle/substrate orientations were identified by EBSD. The effect of a preferential orientation on the spreading kinetics is limited, if any. A general agreement is found between the kinetic results and numerical calculations of Mullins [1] for mass transport by surface diffusion under the action of surface curvature gradients. The experimental kinetics are however significantly more rapid, due to the contribution of other mechanisms like volume diffusion.