Chemical Precursor Synthesis of Complex & Non-equilibrium Oxides; Sintering & Hot Pressing of Advanced Ceramics and Composites; Electron Beam Physical Vapour Deposition (EBPVD).
X-ray Diffractometry; Electron Microscopy (Scanning & Transmission); Focused Ion Beam (FIB); Atomic Force Microscopy (AFM); Mechanical Testing; Thermal Analysis; Surface Area Measurement; Raman & IR Spectroscopy.
Materials Department, University of California, Santa Barbara, CA, USA; 2001 to 2005. Thermal Barrier Coatings – Deposition and Basic Studies:
Growth of multi-material multi-layered thermal barrier coatings (TBC’s) during EBPVD, using TEM, FIB, SEM and XRD.
High temperature performance evaluation of TBC’s. Topics include thermochemical compatibility of Gd2Zr2O7 and ZrO2-YO1.5 bi-layered TBC; high temperature phase stability in rare-earth doped zirconia; mechanism of inter-mixed zone formation in TBC systems (collaboration with University of Pittsburgh). Failure mechanisms of TBC’s, using fracture toughness and high temperature experiments on plasticity of zirconia TBC’s (related to erosion and foreign object damage).
Morphological stability and sintering resistance of high temperature coatings by surface diffusion experiments based on AFM characterisation of grain boundary grooving.
Processing and Phase Selection in Oxide Ceramics:
Ionic conducting phases in TiO2-YO3/2-ZrO2 system were studied in terms of thermodynamics of metastability and kinetics of phase transformations at high temperatures. Ionic conductivity was measured in collaboration with California Institute of Technology.
Chemical precursor synthesis of ZrO2-based thermal barrier coating (TBC) materials, TiO2-YO3/2-ZrO2 based ionic conducting materials, and metastable solid solutions in YAG. A novel plasma spraying technique was developed in collaboration with SUNY - Stony Brook, by combining reverse co-precipitation and liquid precursor plasma spraying.
Collaborations with other research groups, writing reports and research proposals, active mentoring of Ph.D. students and interns, assistance in advanced level teaching.
High pressure consolidation technique was developed for processing Al2O3 based bulk metastable amorphous ceramics.
Discovery of large-scale plasticity in amorphous ZrO2-Al2O3.
Vacuum hot press installation, operation and maintenance of a conventional vacuum hot-press. Advanced ceramic matrix composites processing.
Mentoring of M.E. students and interns; organisation of symposia, student seminar series, and social events.
Contact-less processing of ceramics: Development of an aerodynamic levitation method for up to 2200˚C; Rapid solidification studies on Al2O3-BaO system using the levitation apparatus.