采用等离子喷涂方法(APS)在GH30高温合金表面分别制备了纳米ZrO₂-8%Y₂O₃ (YSZ, 质量分数)和掺杂25%(质量分数)纳米CeO₂的三元CeO₂/ZrO₂-8%Y₂O₃(CSZ)热障涂层. 使用FESEM和XRD分析了涂层的微观组织, 研究了CSZ涂层在1100 ℃加热条件下分别保温不同时间及固定加热时间10 h, 改变加热温度时涂层晶粒尺寸的变化情况, 测试了2种涂层在高温下的耐Na₂SO₄熔盐腐蚀能力. 结果表明, CSZ涂层在高温长时间加热时, 平均晶粒尺寸从喷涂态的45 nm增至63 nm, 变化较小, 在900 ℃, Na₂SO₄熔盐腐蚀条件下长时间加热无m-ZrO₂相析出, 耐蚀性能要高于YSZ涂层.

Thermal barrier coating (TBC) systems are being used in thermal insulation components in the hot sections of gas turbines in order to increase operation temperature with better efficiency. The typical material of TBC is yttria stabilized zirconia (YSZ) because of its high thermal expansion coefficient, which closely matches that of the substrate, and low thermal conductivity. However, YSZ based TBC systems cannot be successfully applied due to hot corrosion problems caused by molten salts, such as Na, S and V, contained in low quality fuels. In recent years, nanostructured TBC attracted intense attentions due to their enhanced thermal physical properties, but the thermal stability and resistance to molten salt performance are rarely studied.As a new candidate TBC material, ceria and yttria stabilized zirconia currently looks to be promising. The purpose of this work was to obtain the better understanding of microstructure and molten salt corrosion capability of plasma-sprayed nanostructured CSZ coating and to provide some foundation for improving the properties of TBC. In this work, nano-sized ZrO₂-8%Y₂O₃ (YSZ, mass fraction) and nano-YSZ doped with 25% of nanometer CeO₂ (CeO₂/ZrO₂-8%Y₂O₃, CSZ) were deposited on GH30 superalloy surface through air plasma spray process (APS) to form a thermal barrier coating. The morphology and microstructure of the CSZ coating were characterized using FESEM and XRD. The grain size of CSZ coating under the following two conditions were examined, firstly, the CSZ coating was heated to 1100 ℃ and held for various durations, thenthe CSZ coating was heated for a fixed 10 h but up to various temperatures. Its corrosion resistance under high temperature molten Na₂SO₄ salt was also tested. The results showed that average grain size of CSZ coating grown from 45 to 63 nm under prolonged exposure to high temperature and CSZ has showed better corrosion resistance than YSZ coating with no m-ZrO₂ phase precipitated at under prolonged high temperature at 900 ℃ in Na₂SO₄ salt corrosion.