This project supports a collaborative research between Dr. Leon Shaw, Department of Materials Science and Engineering, University of Connecticut (UConn) and Dr. and Mahmoud Zawra, National Research Center (NRC), Cairo, Egypt. They aim at preparation and characterization of advanced ceramic material (nano silicon carbide) from waste material (silica fumes) as starting material. Intellectual Merit: Silica fume contains more than 94-97% (by weight) of silicon dioxide (SiO2) and is produced as a waste material from silicon and ferro-silicon alloy industry in Egypt. This waste material causes many pollution problems. The PIs will first evaluate the silica fumes, then prepare nano-SiC by a novel process, the integrated mechanical and thermal activation (IMTA) process, developed recently for synthesizing large quantities of low cost, high quality, nanostructured carbides and nitrides. Different parameters such as milling speed, ball-to-powder weight ratio, milling atmosphere, milling environmental temperature and time will be investigated. Changes in crystal structure, microstructure, particle size, particle morphology, structural defects and amorphization of powder mixtures as a function of milling parameters will be characterized. A variety of analytical instruments at the NRC in Cairo and the Uconn. in Storrs, such as X-ray, SEM and TEM attached with EDS, will be utilized to characterize particle and crystal sizes, morphology, crystal structure, structural defects, and phase composition. Sintering of the nano-SiC powder produced from waste silica fume at different firing temperatures, pressures and atmospheres, with and without sintering aids, will also be studied. Physical and mechanical properties of the sintered nano-ceramic bodies will be investigated.
Broader Impact: The preparation of advanced material from waste material has two advantages, first is eliminating the waste material, and second is the production of nano-materials which have advanced applications such as in the form of cutting and grinding tools, abrasive media, mechanical seals, blasting nozzles, armor tiles and bullet-proof vests. The project results can be applied to convert a waste material, silica fumes, to an advanced ceramic, SiC, and to reduce pollution from the silica fumes while producing a useful ceramic material. The process could conceivably be applied to other cases with broad impact in reducing pollution and converting waste to useful material. The U.S. PI is the developer of the new processes and will be able to apply the techniques to a new material in a reasonably large scale, thus putting them into useful practice and providing a first test of large-scale application. The Egyptian PI will be able to learn the new technologies and train younger scientists in materials processing, and help reduce pollution caused by the manufacture of silicon and ferrosilicon alloys in Egypt. The project will involve support for at least one U.S. graduate student. This project is being supported under the US-Egypt Joint Fund Program, which provides grants to scientists and engineers in both countries to carry out these cooperative activities.
