THIS IS A CONTINUATION OF N000141410546 - Controllable Sintering of Sulfide-Based Infrared Nanoceramics
Abstract
Synthesis techniques will be developed for the production of nanoparticles of ZnS and other candidate phases including La-Ca-S using preclitation chemistry approaches. The particles will be purified and characterized for size distribution and morphology. Nanoparticles will be blended in various ratios and consolidated via conventional ceramic techniques. Resulting materials will be characterized for both mechanical and optical properties. The Program Officer of this award is Dr. Antti Makinen. The primary objective of this research is to study and develop high performance ZnSbased long wave infrared (LWIR) ceramic nanocomposites. The research will focus on investigating the fundamentals of mass transport for the sintering, the chemistry, the structure of the interface and grain boundaries, and the development of a new gelling system for near-netshape processing. Emphasis will be placed on gaining an improved understanding of the mechanisms controlling the grain growth, the densification, and eventually the optical and mechanical properties of the nanocomposite which can then be applied to developing the enhanced LWIR optical ceramics. The critical advantage of the proposed process is that the grain growth will be manipulated to maintain nanometer size grains through the addition of a CaLa2S4 secondary phase and a controlled sintering profile. Another advantage is the inclusion of additives which can further improve the mechanical properties by increasing the fracture energy and blocking crack propagation. The nano-scale phases of the composites will allow the materials to be LWIR-transparent. The development and applications of these high performance LWIR ceramics will enable the US Department of Defense to maintain their leading position in the scientific and technical development of enhanced, durable windows and domes for high speed national defense optical systems. Figure 1 shows some transparent ceramics developed by PI’s group. The technical approaches will be primarily based on the wet chemical processing of nanoparticles, colloid chemistry for the preparation of the homogenous slurries, advanced sintering for densification, microstructural investigation of the interfaces and grain boundaries, and characterization of the optical and mechanical properties. With the success of this effort, it will be possible to develop high performance three dimensional ZnS-based ceramic nanocomposites with the requisite optical and mechanical qualities through advanced ceramic techniques and the near-net-shape processing of ceramics for applications in industry of national defense. Fundamental studies of the chemistry and structure of the developed nanocomposites will provide theoretical guidelines for developing next generation infrared ZnS-based ceramics with enhanced mechanical properties that maintain a high level of optical transmission. This will be undertaken by controlling the microstructure and composition of the ZnS-based composites. The proposed efforts will have a wide impact in the DoD’s defense system community through the research, development, and applications available through these ZnS-based nanocomposites.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 23, 2016
- Source ID
- N000141612404
Entities
People
- Yiquan Wu
Organizations
- Alfred University
- Office of Naval Research
- United States Navy