熱応力緩和層を有するZrO2/Ni系遮熱コーティング材料のNTO/MMH燃焼ガス加熱場におけるレーザ改質効果

Evaluation test of the laser cracking specimens applied to the ZrO2/Ni functionally graded materials (FGM) and also applied to the non-FGM has been described. In this test, 30 mm disk specimens of these materials were exposed to the combustion gas of nitrogen tetroxide (NTO)/monomethyl hidrazine (MMH) propellant. The delamination and the vertical crack formation of the ZrO2 thermal barrier coating were observed during the heating test. It has been found that the laser cracking method seemed to be effective at preventing delamination in the coating layer of the test specimens. The crack and the delamination formation mechanism for ZrO2/Ni FGM test specimens were also discussed with a thermal stress analysis by using a finite element method.