Silver catalytic effect on flash sintering of ceramics
Isabela R. Lavagnini,
Bola Yoon,
Viviana Avila,
Sanjit K. Ghose,
Rishi Raj,
Eliria M.J.A. Pallone,
Lílian M. Jesus,
João V. Campos
Affiliations
Isabela R. Lavagnini
Departamento de Engenharia de Biossistemas, Universidade de São Paulo, USP AV. Duque de Caxias Norte, 225, Pirassununga, SP, Brazil; Department of Materials Engineering, Federal University of Sao Carlos, 13635-905, Sao Carlos, SP, Brazil; Department of Mechanical Engineering, University of Colorado at Boulder, Colorado, 80309-0427, USA
Bola Yoon
Department of Mechanical Engineering, University of Colorado at Boulder, Colorado, 80309-0427, USA
Viviana Avila
Department of Mechanical Engineering, University of Colorado at Boulder, Colorado, 80309-0427, USA
Sanjit K. Ghose
National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
Rishi Raj
Department of Mechanical Engineering, University of Colorado at Boulder, Colorado, 80309-0427, USA
Eliria M.J.A. Pallone
Departamento de Engenharia de Biossistemas, Universidade de São Paulo, USP AV. Duque de Caxias Norte, 225, Pirassununga, SP, Brazil; Postgraduate Programme in Materials Science and Engineering, University of São Paulo, USP/FZEA, Av. Duque de Caxias Norte, 225, 13635-900 Pirassununga, Brazil
Lílian M. Jesus
Group of Advanced Functional Materials (MAFA), Department of Physics, Universidade Federal de São Carlos (UFSCAR), São Carlos, SP, 13565-905, Brazil
João V. Campos
Department of Materials Engineering, Federal University of Sao Carlos, 13635-905, Sao Carlos, SP, Brazil; Department of Mechanical Engineering, University of Colorado at Boulder, Colorado, 80309-0427, USA; Corresponding author. Department of Materials Engineering, Federal University of Sao Carlos, 13635-905, Sao Carlos, SP, Brazil.
We investigated the use of metallic silver as a catalyst for flash sintering on hydroxyapatite/zirconia (HZ) composites. Adding 3 wt% of silver to the ceramic powder reduced the flash onset temperature (from 1084 °C to 925 °C) and also the electric field (from 300 V cm−1 to 150 V cm−1) used in the process. We attribute this behaviour to the formation of a silver percolation path that acts as a heat source, accelerating the thermal runaway. As a result, both the flash temperature and the required electric field were reduced. Furthermore, the results suggest that the temperatures along the percolation paths are high enough to reach the boiling point of silver, forming a gaseous phase that leaves the sample.
