Research Projects

Considerable research efforts have been directed in developing Si3N4 ceramics with high thermal conductivity with good mechanical properties in view of its potentiality for power electronic device applications along with its other demanding applications like orthopedic implants, automotive engine parts, turbine blades, high-performance bearings, glow plugs, cutting tools, wear resistant parts, armor applications, etc. However, the commercial applications of Si3N4 are mainly limited due to its high processing costs. Recently, cold sintering process (CSP) gained a lot of interest in the materials research community as it is a new and highly promising processing technique to process ceramics at very low temperatures (below 300oC) and even in short times (less than 60 minutes). Hence, CSP will be attempted to prepare Si3N4-SrTiO3 composites at low processing temperatures (which will lower its cost) and explore the potential of these new composites for electronic substrate and bio-applications. In cold sintering, the ceramic materials are densified at very low sintering temperatures by combining it with an aqueous/liquid medium such as deionized water, acetic aqueous solutions, organic solution, molten secondary phase and apply high pressures to densify the ceramics. In fact, CSP is a breakthrough in ceramic processing as it considerably reduced sintering temperature and time. The CSP process has been proven successful for oxide ceramics such as Al2SiO5, ZnO, ZrO2, MgO, BaTiO3, Li2MoO4, LiFePO4, Hydroxyapatite (HA) and NaNO2 etc. Most of the studies involved on densification, microstructural characterization, electrical and electrochemical properties of these oxide ceramics. However, lacking is the studies on the non-oxide ceramics and composite materials development. The CSP is a green processing technique, energy efficient and beneficial to obtain nanocrystalline ceramics. In the present work, the CSP of Si3N4-SrTiO3 will be carried out and its potential applications for electronic substrate and bio-applications will be explored. Although the CSP has been researched more in USA, Europe, UK and China, very limited research is being done in India. Also CSP has not been attempted for non-oxide ceramics. In this context, working on CSP of Si3N4-SrTiO3 composites is a new contribution. In the proposed work, densification of materials, microstructural characterization (SEM, EBSD, TEM), sintering mechanisms, mechanical properties (hardness, elastic modulus, strength), dielectric and bioactivity properties will be evaluated and possible application of these materials will be identified.