Sintering behavior and anisotropic sintering parameters of uniaxially constrained LTCC tapes

摘要

The constrained sintering behavior of uniaxially loaded commercial LTCC tapes was studied by recording sintering strains through an optical dilatometer. By adjusting the applied uniaxial load, zero uniaxial strain rates can be achieved at several densities. Pores were found to be more inclined to elongate along the loading direction and a pore orientation factor around 1.2 was observed in uniaxially constrained tapes. Uniaxial sintering stress was determined for the uniaxially constrained tape, showing an obvious misfit with the theoretical prediction. Moreover, by utilizing the simplified anisotropic continuum mechanical formulation, the uniaxial viscosity and viscous Poisson's ratio can be determined. Comparing with those in isotropic sintering cases, a larger anisotropic uniaxial viscosity and a lower viscous Poisson's ratio were obtained as a result of the evolved anisotropic microstructure. Reasons responsible for the observed discrepancies were discussed in detail. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.