Photoluminescence peizospectroscopy for non-destructive residual life assessment of thermal barrier coatings

摘要

A quantitative approach, based on measurement of oxide tress evolution as g function of thermal cycling is described for identifying thermal barrier coating (TBC) damage and assessing remaining life. Residual stress in the thermally grown oxide was measured using photostimulated luminescence piezospectroscopy for electron beam physical vapour deposited TBCs, which were thermally cycled at three temperatures and over two cycling periods. The observed monotonic change in the oxide stress level with TBC life fraction is systematic with cycle time and nearly independent of exposure temperature. The temperature independence of the measured with life fraction would greatly simplify the use of this technology for the non-destructive evaluation of TBCs.