|About this Abstract
||2010 TMS Annual Meeting & Exhibition
||Processing Materials for Properties
||Transparent Ceramics by Spark Plasma Sintering of Oxide Nanopowders
||Rachman Chaim, Zhijian Shen, Claude Estournes
|On-Site Speaker (Planned)
Spark plasma sintering (SPS) was used for superfast densification of ceramic nanopowders. Simultaneous application of pulsed dc currents and load are the necessary conditions for rapid and full densification of ceramic nanopowders by SPS. Nanopowders of MgO, YAG and Y2O3 were densified using SPS at different temperatures, pressures and durations. Nanocrystalline MgO and YAG powders were densified to optical transparency at distinctly different homologous temperatures (0.3Tm for nc-MgO and 0.7Tm for nc-YAG). Dense Nd-YAG and Y2O3 specimens were translucent with micrometer grain size. Analysis of the density and grain size evolution versus the SPS parameters showed that densification of these nanopowders proceed either by plastic deformation, grain-rotation coalescence and sliding, aided by softening of the particle surfaces or by accelerated surface diffusion. These may be followed by normal grain growth. The active densification mechanism depends on the changes both in the mechanical and electrical properties of the ceramic with temperature.
||Definite: A CD-only volume