Model for Sintering Devitrifying Glass Particles with Embedded Rigid Fibers
Abstract:We extend the Clusters model to account for the presence of rigid inclusions and use it to analyze the experimental sintering kinetics of composites of 60SiO2·24B2O3·16Na2O glass particles and zirconia fibers. We followed the densification kinetics of such composites as a function of the particle size, volume fraction of fibers, fiber to pore size ratio, temperature, and time of thermal treatment. The parameters of the extended Clusters model are the glass particle size distribution and shape factor, the fiber volume fraction and radii, the glass viscosity and surface tension, the number of nucleating sites per unit surface, and the crystal growth rate in the parent glass. Hydrostatic tensions caused by the fibers were also included in the calculations. The modified Clusters model with only one adjustable parameter, which is largely dominated by viscosity but also includes particle shape, allowed us to account for the effect of surface crystallization and fiber content as inhibitors of densification and successfully describe the sintering kinetics of the studied composites.
Document Type: Research Article
Affiliations: 1: Instituto de Cerámica y Vidrio (CSIC), Campus de Cantoblanco, 28049 Madrid, Spain 2: Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, 8400-SC de Bariloche, RN, Argentina 3: Department of Materials Engineering-DEMa, Federal University of São Carlos-UFSCar 13565-905, São Carlos, SP, Brazil
Publication date: June 1, 2005