Dr.-Ing. Ravisankar Naraparaju and Prof. Dr.-Ing. Uwe Schulz form the “high temperature and functional coatings” department successfully published together with Prof. Seetha Raghavan from the University of Central Florida and her former student Estefania Bohorquez a patent in Germany and in the United States.
The invention of the patent refers to the development of 3D Confocal Raman spectroscopy sensing method which will be used to monitor the damage evolution of thermal barrier coatings (TBCs) by means of a volcanic ash or a sand (CaO-MgO-Al2O3-SiO2, in short: CMAS) attack. This is done based on the detection of the atomic phase change. For example, during coating, a tetragonal phase is deposited which transforms into a monoclinic phase due to damage, this transformation can be detected in a depth-specific manner. Thus, this invention provides a new way to non-destructively assess the damage caused by the volcanic ash or sand within the thermal barrier coating system.
Potential applications include aircraft turbine maintenance where the lifetime cycle of the TBCs can be determined and the need for repair or replacement can be provided with a simple scan.