钛合金热障涂层高温氧化和热循环性能

In this study, a thermal barrier coating consisting of 8 mol% yttria stabilized zirconia (8YSZ) ceramic face layer and Ti⁃48Al⁃2Cr⁃2Nb interlayer was coated via high velocity oxygen fuel (HVOF) and atmospheric plasma spraying (APS) techniques. The high-temperature oxidation and thermal cycling properties of the coatings prepared by the two techniques were tested compared. After high-temperature oxidation, thermally grown oxide (TGO) layers were observed in both coatings. The TGO consisted of Al₂O₃ and TiO₂, located between the 8YSZ and Ti⁃48Al⁃2Cr⁃ 2Nb layers. However, the interfacial cracks in the coating produced by APS were eliminated after the oxidation, while the cracks still existed in the coating made by HVOF due to overgrowth of the TGO. The oxygen content of the two coatings slightly increased after thermal cycilng text, and no delamination was observed, suggesting good thermal shock resistance. Comparing the microstructures and high-temperature properties of the two coatings, the one prepared by APS has more dense and uniform microstructures, and better thermal oxidation resistance and thermal shock resistance.