Engineering Ceramics

Engineering ceramics referred as advanced, structural or fine ceramics - have been processed to be very pure and, in general, have superior properties to unrefined ceramics. Engineering ceramics are used in 'high-tech' applications such as aerospace, electronics, biomedicals. Ceramic products can be briefly categorized as white ware, refractory or engineering - generally a function of their end-use. White wares (e.g. dinner plates) are familiar and refractories are used in applications such as furnace linings and crucibles. Sintering and micro-structural studies of refractory oxides like Al2O3 , ZrO2 , MgO, Cr2O3 etc. are carried out to attain the maximum sintered densities and desirable microstructure so that optimum refractory properties are obtained in the end product.

Few examples are given below:

Manufacturing process of Ultra Light Weight energy saving heat insulating ceramic materials :
Recently, porous ceramic materials containing Bird's nest-like structure, has drawn attention to the researchers due to possessing of low density, low thermal conductivity and reasonable high mechanical strength. For this reason, they are being used for thermal insulation such as lining in furnace and kilns, duct liner, expansion joints, Heat shields for automobile engines, seal packaging and gaskets for pumps, high-temperature electrical insulation etc. In this project (funded by HEQEP), an attempt has been taken to synthesize ceramic fibers from indigenous clay by blowing method. In this process, raw materials are melted in an electric arc furnace (EAF) followed by blowing in compressed air and curing in hot blast furnace. Finally, the as- synthesized fibers is shaped in different forms such as blanket, board etc. for practical use. This manufacturing technique able to generate defect free ceramic fibers with controlled porosity and pore size with appropriate comprehensive strength for modern engineering applications.

Figure : Ultra Light Weight energy saving heat insulating ceramic materials production flow chart
Refractories Ceramic Materials:
Refractories are indispensible thermal barrier materials for many industrial applications which include Glass furnace, Ceramic Kiln, Steel, Cement and Chemical industries. The department of Glass and Ceramic Engineering (GCE), BUET is conducting research to develop low cost Silica, Chrome-Magnesite, Alumina-Zirconia-Silica (AZS) refractories with improved characteristics and properties having enhanced mechanical and thermal properties keeping in pace with the recent extensive growth of the Glass, Ceramic, Steel, Cement and Chemical industries in Bangladesh. Although the research status on refractories is now at the initial stage, enormous effort is being put forward in collaboration with Nasir Glass Industries Limited to develop these useful materials for future multidimensional utility by the industries and economic growth of the country. GCE is focusing R & D on specific materials of industrial importance are namely Super duty Silica bricks, Zirconia-Mullite Bricks , Bonded AZS- refractories, High Alumina Bricks with varying amounts of constituent ingredients. The objective is to optimize composition, processing parameter and appropriate thermal treatments for attaining the suitable mechanical, thermal and chemical properties.

Anti bacterial ceramics by nano synthesis :
Department of GCE, BUET has developed a state-of-the-art facilities for nano material synthesis and their characterization. For the last three years different types of nano materials which include - BiFeO 3 with various dopants, TiO 2 , ZnO 2 , BaTiO 3 , CeO 2 have been successfully synthesized with varying particle size from 3 nm to 70 nm with controlled morphology for various engineering applications. Green synthesis of nano materials using plant leaf extracts as a reducing agent have also been successfully established. The research carried out using CeO 2 by green nano synthesis using jack fruit leaf have found potential application and capabilities in the destruction of bacteria and cancerous cells. Attempts are being made to use these large band gap nano materials synthesized in our laboratory as efficient anti bacterial and anti microbial weapons to destroy all kinds of pathogens.
Anti bacterial ceramic tiles possess excellent lucrative and chemical durability, and are widely used in various areas such as in the hospital environment, pharmaceuticals lab and in household. Ceramic tiles itself does not have antibacterial activity thus micro organisms can easily breed on its surface, especially in moist environment, which may harm people's health. Various types of nano particles such as - TiO 2 , ZnO 2 , CeO 2 etc. can be used as an anti bacterial coating in tiles. These anti bacterial nano particles can destroy up to 650 different types of bacteria. These nano particles or nano composite can be mixed with tile's glaze as an additive, which can penetrate the cell walls of bacteria and micro organisms, making them unable to function, grow and reproduce.

Affiliated faculty: Dr. Md. Fakhrul Islam, Dr. Abdul Hakim, Dr. Md. Abdul Matin