SEMINAR: Materials Challenges for the Next Generation Thermal Barrier Coatings

Abstract:

One of the major successes of engineered ceramics has been the development of the thermal protection system for high-temperature gas turbines. For the last twenty-five years, the ceramic material of choice as a thermal barrier coating has, and continues to be, yttria-stabilized zirconia containing 8 weight percent yttria (8YSZ).  As the development of more efficient gas turbines proceeds there is a need for an oxide coating that can sustain higher operating temperatures than 8YSZ. However, no existing oxide has the required combination of low thermal conductivity, adequate fracture toughness, low optical absorption in the infra-red and high temperature stability as well as compatibility with alumina that forms on superalloys at high temperatures. In this presentation, Dr. David Clarke will discuss the design requirements for the next generation gas turbines as well as the new, additional challenges that coatings must meet to operate at the higher temperatures of the next generation engines.

Bio:

David R. Clarke is the inaugural holder of the Extended Tarr Family Professor of Materials in the Harvard School of Engineering and Applied Sciences. He holds a PhD in Physics from the University of Cambridge, a B.Sc. in Applied Sciences from Sussex University and was awarded a ScD from the University of Cambridge.

A member of the National Academy of Engineering since 1999, he is also a Fellow of both the American Physical Society and the American Ceramic Society, and received an Alexander von Humboldt Foundation Senior Scientist Award in 1993. He shared the 2008 Japanese NIMS Award for Recent Breakthroughs in Materials Science for Energy and Environment, is a Distinguished Life Member of the American Ceramic Society and was recently listed as author of one of the 11 best papers in the 110 years of publications on ceramics and glasses.

His long-term interests in materials range from the fundamentals to the applied, from ceramics to metals to semiconductors and polymers. He has published over 450 papers in areas of materials ranging from thermal barrier coatings, to dielectric elastomers to fundamentals of oxidation to microelectronics reliability and the electrical and optical properties of ZnO and GaN.

At Harvard, he enjoys interacting with students at all levels, from teaching Freshman seminars on “Glass” and  “Materials, Energy and Society”, graduate courses in composites and deformation of materials and the new undergraduate course in SEAS on “Fundamentals of Heat Transfer”, a required course for students studying Mechanical Engineering.