Phosphor thermometry device for synchronized acquisition of luminescence lifetime decay and intensity on thermal barrier coatings

A phosphor thermometry device for temperature monitoring of turbine components, comprising:

• a laser that generates a laser pulse onto a thermal barrier coating (TBC) applied onto a superalloy turbine component substrate, the thermal barrier coating including a metallic bond coat layer on the superalloy turbine component substrate, and a ceramic top coat layer on the bond coat layer, the ceramic top coat layer including an undoped layer and a doped sensing layer having co-doped first and second rare-earth luminescent dopants that emit respective first and second different emission wavelengths upon excitation by the laser pulse;
• a first dichroic filter configured to transmit the laser pulse onto the TBC and reflect convoluted luminescence signals from the TBC generated from the laser excitation of the first and second rare-earth luminescent dopants in the doped sensing layer;
• a second dichroic filter positioned to receive the convoluted luminescence signals from the first dichroic filter and split the convoluted luminescence signals into two spectral bands corresponding to the respective emission wavelengths of the respective first and second rare-earth luminescent dopants;
• a detector that receives the convoluted luminescence signals from the second dichroic filter, said detector including first and second photomultiplier devices configured to detect respective first and second different emission wavelengths of the convoluted luminescence signals from the second dichroic filter and generate first and second output signals indicative of the respective first and second different emission wavelengths of the convoluted luminescence signals;
• and
• a controller connected to the detector and configured to receive and process first and second output signals generated from respective first and second photomultiplier devices, determine from the first and second output signals a luminescence lifetime decay and intensity variations for each of the respective first and second rare-earth luminescent dopants, and correlate the determined luminescence lifetime decay and intensity variations for each of the respective first and second rare-earth luminescent dopants to a temperature value for temperature monitoring of the turbine component.

A method of operating a phosphor thermometry device for monitoring a temperature of thermal barrier coatings (TBC), comprising:

• generating, from a laser, a laser pulse onto a TBC applied onto a substrate, the thermal barrier coating including a metallic bond coat layer on the substrate, a ceramic top coat layer on the bond coat layer, the ceramic top coat layer including an undoped layer and a doped sensing layer having co-doped first and second rare-earth luminescent dopants that emit respective first and second different emission wavelengths upon excitation by the laser pulse;
• receiving, at a detector convoluted luminescence signals from the TBC as generated from the laser excitation of the first and second rare-earth luminescent dopants in the doped sensing layer, the detector including first and second photomultiplier devices configured to detect respective first and second different emission wavelengths of the convoluted luminescence signals and generate first and second output signals indicative of the respective first and second different emission wavelengths of the convoluted luminescence signals;
• receiving, at a controller connected to the detector, the first and second output signals generated from the respective first and second photomultiplier devices, processing the first and second output signals to determine a luminescence lifetime decay and intensity variations for each of the respective first and second rare-earth luminescent dopants and correlating the determined luminescence lifetime decay and intensity variations for each of the respective first and second rare-earth luminescent dopants to a temperature value for temperature monitoring of the TBC.