渗铝对CoCrAlY溅射涂层抗热腐蚀性能的影响

EFFECT OF ALUMINIZING ON THE HOT CORROSION RESISTANCE OF THE SPUTTERED CoCrAlY COATING

一、前言 MCrAlY涂层具有优良的抗热腐蚀性能,适用于运行参数高、使用环境恶劣的燃气轮机涡轮叶片。用离子溅射工艺制备的MCrAlY涂层,具有成份容易控制,组织比较致密的优点,因而越来越受到重视。此工艺需用与涂层同成份合金制成的靶,但由于机械加工的原因,常选用高铬低铝型靶材。这种类型的MCrAlY涂层在熔融硫酸盐环境中具有良好的抗热腐蚀性,但在含氯化钠的熔盐环境中抗蚀性变差,热腐蚀孕育期缩短。

The hot corrosion behaviour of Co-30Cr-6Al-0. 5Y coating produced by magnetron sputtering deposition and that of the said coating with subsequent aluminizing have been investigated in sulphate melt,but its hot corrosion resistance in molten salts. The results show that the CoCrAlY coating possesses excellent hot corrosion resistance in sulphate melt,but its hot corrosion resistance in molten salts containing NaCl is reduced severely after 100 hrs. With subsequent aluminizing of the CoCrAlY coating its resistance to hot corrosion is only slightly reduced in sulphates melt and is remarkably improved in salt melt containing NaCl. The different influence factors of aluminizing on the hot corrosion resistance of the CoCrAlY coatings in various salt melts have been discussed.