Reaction of ZrO2–CaO–ZrSiO4 and ZrO2–Y2O3–ZrSiO4 detonation thermal sprayed coatings with manganese oxide at 1273 K

Phase transformations and the reaction of ZrO2–CaO–ZrSiO4 and/or ZrO2–Y2O3–ZrSiO4 coatings with manganese oxide at 1273 K were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). SiO2 phase formed in the coatings, mainly due to the decomposition of ZrSiO4. SiO2 reacts easily with manganese oxide or calcium oxide, it will react preferentially with CaO rather than MnO for the ZrO2–CaO–ZrSiO4 coating and the CaO depletion will ultimately result in the t–m reaction occurring on cooling. The reaction between SiO2 and MnO primary occurs in the ZrO2–Y2O3–ZrSiO4 coatings and result in the damage or exfoliation on the surface of a coating.