A micro-mechanistic approach to lifing of thermal barrier coatings for gas turbine blades

Description/Abstract

A summary of progress made in micro-mechanistic approach to lifing of thermal barrier coatings for gas turbine blades. Aim is to develop a model for Thermal Barrier Coating lifetimes that predicts the physical changes occurring in terms of morphology and physical properties of the materials involved and combines these to predict failure lifetime under thermo-mechanical fatigue (TMF) conditions. A test matrix has been designed to isolate the effects of the various damage mechanisms and includes: (a) isothermal exposures, (b) Single step thermal exposures, (c) Thermal cyclic tests (d) a creep test and (e) TMF tests. The TMF testing uses a susceptor to produce representative temperature profiles as seen in service across the specimen. Initial results of the thickness of the Thermally Grown Oxide (TGO) layer are presented. A TMF test capability for TBCs that simulates conditions seen in service has been demonstrated.