Experimental determination of sintering stresses and sintering viscosities

A loading dilatometer assisted by two high-resolution lasers was applied for the accurate measurement of radial and axial strains during uniaxial load assisted sintering. An improved hot forging technique was employed for the first time for the experimental determination of sintering stress and sintering viscosity by hot forging samples under various loads which were pre-sintered to different densities. The technique of discontinuous hot forging was discussed in detail and the effect of the developing anisotropy and different grain growth were analysed. The sintering stress and uniaxial viscosity were both obtained as functions of density ranging from 65 to 96% and compared with theoretical models. Alumina powder with a grain size of about 150 nm was used in this study.