Methods to reduce the thermal conductivity of EB-PVD TBCs.

摘要

This paper reviews the advantages and disadvantages of various thermal barriercoating (TBC) systems, with the aim of custom designing a TBC system to be bothstrain tolerant and have a low thermal conductivity. Methods of heat transferwithin zirconia based ceramics are discussed, including the influence of coatingmicrostructure and ceramic composition. It is shown the addition of dopant atoms(colouring) is effective in reducing â  phononâ  transport and that layeredmicrostructures are effective in reducing â  photonâ  transport. Advancedprocessing, using EB-PVD coating methods has allowed both coloured and layeredceramic coatings to be produced. Measured thermal conductivities of 1.0 W mKâ  1have been achieved using these methods, much lower than current commercial EB-PVD coatings at 1.5âÂ