Harold Moore Memorial Lecture
Professor John Nicholls FIMMM, Cranfield University, delivered this year’s Harold Moore Memorial Lecture, as the 2010 winner of the Tom Bell Award. The lecture, on 20 October at the IOM3 London office, covered smart materials and coating concepts, gas turbines and their service environment, thermal barrier coating (TBC) technology and smart designs for TBCs, including lowering thermal conductivity and wavelength selective thermal filters.
Design challenges for materials scientists
John outlined some of the design challenges facing materials scientists, such as servicing turbines that work in extreme conditions. To overcome problems associated with extreme temperature, it is necessary to improve the efficiency of gas turbines, which have to work at high operating temperatures and pressures. Thermal barrier coatings can help overcome these difficulties.
According to John, an ideal sensing TBC would measure the ceramic/metal interface temperature, ceramic surface temperature, heat flux and structural integrity. This would require at least three
thermographic phosphor dopants.
Phosphor thermometry is a promising technology to manufacture smart thermal barrier coatings. It can be used to –
- Remotely measure very high temperatures in-situ (up to 1,500°C).
- Measure temperature at different depths in the TBC.
- Determine the thermal gradient/heat flux through a TBC.
- Monitor TBC degradation (erosion/spallation, molten deposit attack and phase transformations).
- Monitor maximum operating temperatures and engine health at engine shut down.
John Nicholls as recipient of the 2010 Tom Bell Award
John received the 2010 Tom Bell Award for a career going back to 1978 in the field of high temperature surface engineering and corrosion. He established the National High Temperature Surface Engineering Centre and is a world expert on this area of materials science. His seminal work on coating systems to combat high temperature corrosion and wear has led to improved processes and coatings.