Mechanical Stability Diagrams for Thermal Barrier Coating Systems

Abstract Loss of mechanical integrity due to thermal aging and subsequent spallation the ceramic top layer is one dominant failure mechanisms in barrier coating systems. In order predict avoid such failure, a strain-based lifetime assessment model presented for novel double-layer system. The investigated system consists gadolinium zirconate on yttria-stabilized zirconia prepared by atmospheric plasma spraying. stability diagrams generated delineate areas safe operation from where damage becomes imminent. Intensive ceramographic inspection used investigate defect growth kinetics coat after isothermal exposure. Four-point bending experiments with situ acoustic emission measurement are utilized determine critical strain failure. results then generate coatings. From these diagrams, it evident that has significantly lower tolerance than zirconia. However, underlying will provide some protection even when failed.