Atmospheric plasma-sprayed thermal barrier coatings mechanical testing and evaluation

Abstract

The study of thermal barrier coatings (TBC's) has been widely studied in the past years as well as the failure mechanisms associated with them due to the complexity of these multi-layer systems. In addition, life prediction and computerized simulations had become of high importance to predict in a more accurate way the mechanical behaviour of these coatings under operation conditions. But to have good and precise predictions and simulations, accurate data acquisition of the mechanical properties of the TBC's is needed to be determined by reliable experimental test procedures. For the metallic substrate and bond coat (BC) cases, is easier to determine their mechanical properties (such as hardness, Young's modulus, Poisson's ratio, fracture toughness, etc.) due to their ductile behaviour and easiness to be tested in with different methods, having a small variance between measurements. However, this is not so easy to do with the yttria-stabilized zirconia (YSZ) ceramic top coat (TC) because of its brittle behaviour and its microstructure correlation formed by air-plasma sprayed (APS) manufacturing process and the difference between this deposited thin layer and the fully dense (bulk) material. Furthermore, these coatings present a mechanical evolution of their properties at their high temperature operation (

Date of Award	31 Dec 2016
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Ping Xiao (Supervisor) & Philip Withers (Supervisor)