| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Solid-state Optical Materials and Luminescence Properties
|
| Presentation Title |
Non Rule-of-mixtures Thermal Expansion in Core-shell Based Nanocrystalline Composite Ceramics |
| Author(s) |
James A. Wollmershauser, Kevin P Anderson, Benjamin L Greenberg, Heonjune Ryou, Edward P Gorzkowski, Boris N Feigelson |
| On-Site Speaker (Planned) |
James A. Wollmershauser |
| Abstract Scope |
Nanocrystalline ceramics demonstrate property improvements over larger-grain-sized ceramics such as increased hardness, strength, and, in the case of birefringent ceramics, visible light transparency. Modeling has also suggested the possibility to actively modulate visible light transparency when harnessing intrinsic electro-optic effects in fine-grained ceramics. However, when designing optical ceramics for integration into components, other properties such as thermal expansion become important. One avenue to design thermal expansion is through combining materials with different coefficients of thermal expansion into a single composite ceramic. Recent work at NRL has combined particle atomic layer deposition (pALD) with Environmentally Controlled – Pressure Assisted Sintering (EC-PAS) to synthesize dense nanocomposite ceramics from core-shell nanopowders. Limited experiments suggest that CTE of these nanocomposites do not follow a simple rule-of-mixtures law, opening the possibility to design CTE outside of these bounds while potentially harnessing other benefits of nanocrystalline ceramics, such as improved mechanical properties. |