Novel Processing of Infrared Transmitting ZrO2-ZrW2O8 Nanocomposites
Final rept. Sep 2012-Mar 2013
IOWA STATE UNIV AMES
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In our research we were able to synthesize ZrW2O8 and ZrW,Mo2O8 single crystals to determine some basic properties including IR transparency as a function of temperature, hardness, and elastic modulus. We were also successful in preparing nanopowders with varying Mo content and determined structure, morphology, CTE, thermal stability as well as infrared transparency. Compatibility of ZrW,Mo2O8 with ZrO2 has also been established while other oxides reacted with ZrW,Mo2O8. Attempts to process fully dense nanocomposite by traditional sintering were not successful. Highest density we were able achieve was 92. Densification of ZrW2O8 is limited by its thermodynamic stability I378-1530 K and high volatility of W,Mo. Therefore, novel processing approaches such as melt spinning and flash sintering. The latter seemed to produce nanostructured nearly fully dense nanocomposites. ZrO2 grains were uniformly distributed in the matrix of ZrW2O8. However, the process optimization. IR transmittance and mechanical properties of the nanocomposites were not completed due to expiration of the grant.
- Laminates and Composite Materials