A coating material (20) for coating a machine component (10), especially a gas turbine or a part thereof, comprises a mixture of at least a refractory material and an indicator material having an optical emission (e.g. fluorescence) spectrum which varies in response to a physical parameter of the coated...http://www.google.ca/patents/US8173266?utm_source=gb-gplus-sharePatent US8173266 - Thermal barrier coating with thermoluminescent indicator material embedded therein
