PS-PVD制备YSZ 热障涂层抗熔盐腐蚀研究

Study on Molten Salt Corrosion Resistance of YSZ Thermal Barrier Coating Prepared by PS-PVD

摘要:

为提高舰船燃气轮机上热障涂在海洋环境中层的工作寿命，研究了新型热障涂层在模拟海洋环境下的腐蚀性能。采用等离子喷涂-物理气相沉积（PS-PVD）技术，在已喷涂粘结层（NiCoCrAlY）的DZ40M高温合金基体上制备7YSZ陶瓷层，然后用Na₂SO₄（质量分数45%）+ V₂O₅（质量分数55%）混合熔盐在1 050 ℃下对涂层进行腐蚀实验。利用场发射-扫描电镜、X射线衍射仪、能谱仪对涂层表面和截面的组织结构及1 050 ℃高温熔盐腐蚀后涂层的物相组织和熔盐渗透深度进行了分析。研究结果表明，硫酸盐与钒酸盐的混合盐对涂层中的TGO 层破坏显著，t′-ZrO₂相变与TGO的生长是导致涂层脱落的主要原因。

Abstract:

In order to improve the working life of thermal barrier coatings on marine gas turbines， the corrosion performance of new thermal barrier coatings in simulated marine environments was studied. A 7YSZ ceramic layer was prepared on a DZ40M superalloy substrate coated with a bonding layer （NiCoCrAlY） using plasma spray physical vapor deposition （PS-PVD） technology. Then， the coating was subjected to corrosion experiments using a mixed molten salt of Na₂SO₄ （45% by mass） and V₂O₅ （55% by mass） at 1 050 ℃. The microstructure of the coating surface and cross section， as well as the phase structure and molten salt penetration depth of the coating after high-temperature molten salt corrosion at 1050 ℃ were analyzed using field emission scanning electron microscopy， X-ray diffraction， and energy dispersive spectroscopy. The results have showed that the mixed salts of sulfate and vanadate have significantly damaged the TGO layer in the coating， and the t′-ZrO₂ phase transition and TGO growth are the main reasons for the coating to fall off.