Residual stresses measurement in plasma sprayed TBCs with cold sprayed bond coats by photoluminescence piezospectroscopy

摘要

A non-destructive inspection technique known as photoluminescence piezospectroscopy (PLPS) has been used to measure the residual stresses in the thermally grown oxide (TGO) from thermal barrier coatings (TBC) submitted to furnace thermal cycling at 1121℃. The ceramic layer (YSZ) was applied by atmospheric plasma spraying onto a cold sprayed bond coated Ni superalloy. The residual stresses are analyzed as a function of the thermal exposure. The changes in stress were used to indicate the spallation and damage degree of the coating system.