Pressure-dependent topographic evolutions of cold-sintered zinc oxide surfaces

Abstract

By applying atomic force microscope to the flat in-plane polycrystalline microstructure, pressure-dependent topographic evolutions can be studied with respect to surface dihedral angle and groove geometry. Using a cold-sintered zinc oxide densified at 200 °C as a model system, this study demonstrates an experimental methodology for the quantification of relative grain boundary energetics in cold-sintered material systems and an associated geometric model for connecting the morphological change and underlying mechanochemical phenomenon at various uniaxial pressures ranging from 70 to 475 MPa. Depending on the applied pressure, the anisotropic grain growth, normal grain growth, and coarsening of particles are distinctively observed according to the changes in the groove geometry, suggesting that the growth kinetics can be considered as a function of pressure.