激光合金化改性8YSZ热障涂层的抗热腐蚀性能研究  

Hot Corrosion Resistance of 8YSZ Thermal Barrier Coating Modified by Laser Alloying

作　　者：孙磊 郭雨嘉[1,2,3] 张盼盼 刘蓉 张群莉[1,2,3] 姚建华 Sun Lei;Guo Yujia;Zhang Panpan;Liu Rong;Zhang Qunli;Yao Jianhua(Institute of Laser Advanced Manufacturing,Zhejiang University of Technology,Hangzhou 310023,Zhejiang,China;School of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310023,Zhejiang,China;Collaborative Innovation Center of HighEnd Laser Manufacturing Equipment(National 2011 Plan),Zhejiang Universityof Technology,Hangzhou 310023,Zhejiang,China;Department of Mechanical and Aerospace Engineering,Carleton University,Ottawa KIS 5B6,Canada)

机构地区：[1]浙江工业大学激光先进制造研究院,浙江杭州310023 [2]浙江工业大学机械工程学院,浙江杭州310023 [3]浙江工业大学高端激光制造装备协同创新中心,浙江杭州310023 [4]卡尔顿大学机械和航空工程系,加拿大渥太华KIS 5B6

出　　处：《中国激光》2023年第4期12-22,共11页Chinese Journal of Lasers

基　　金：浙江省“尖兵”“领雁”研发攻关计划(2022C01117);国家自然科学基金青年基金(52105311);浙江省自然科学基金探索项目(LQ21E010002)。

摘　　要：热障涂层可为航空发动机、燃气轮机中的高温部件提供热防护,但其易受高温熔盐腐蚀而过早失效。激光合金化是一种提高涂层抗熔盐腐蚀性能的有效方法。本团队将TiAl3作为自愈合剂,对8%Y_(2)O_(3)部分稳定的ZrO_(2)(8YSZ)热障涂层进行激光合金化改性。将喷涂态热障涂层和激光合金化改性热障涂层在900℃的75%Na_(2)SO_(4)+25%NaCl熔盐环境下进行4 h热腐蚀试验。结果表明:激光合金化改性热障涂层结构致密且表面分布着网状裂纹,改性层保持亚稳态四方相(t’-ZrO_(2))结构;喷涂态热障涂层在900℃腐蚀4 h后,腐蚀产物为单斜相m-ZrO_(2)和Y_(2)(SO_(4))3,表面有较多的热腐蚀产物;激光合金化涂层在900℃腐蚀4 h后,腐蚀产物为少量m-ZrO_(2)和Y_(2)(SO_(4))3,改性层结构未发生腐蚀破坏,涂层保持着结构完整性;自愈合剂TiAl3在高温下发生氧化反应生成的Al_(2)O_(3)和少量TiO_(2)可以填补裂纹,有助于抑制高温腐蚀盐的渗透,从而提高了涂层的抗热腐蚀性能。Objective Thermal barrier coatings can protect hot end components from high temperature,high pressure,and high stresses,which are extensively applied in gas turbine engine blades,combustion chamber,and ducting and nozzle guide vanes.However,many impurities (sodium,sulfur) exist in the operating gases and fuels,condensation of which leads to the formation of molten corrosive salts during the long-time service process,which may lead to the serious hot corrosion failure and reduce the lifetime of thermal barrier coatings.Plasma-sprayed thermal barrier coatings possess the typical characteristic of pores and laminar structure,which may provide penetration paths for molten corrosive salts into the coating.To improve the hot corrosion resistance,it is necessary to produce a denser layer to prevent molten salts from penetrating into porous coatings.Laser alloying technology has the advantages of high energy density,short action time,and reliable processing quality,and thus can change the loose porous structure of the plasma-sprayed thermal barrier coatings.Meanwhile,the oxidation reaction of self-healing materials at high temperature can produce some oxidation products,which can further fill the pores and cracks in the porous coatings.Therefore,the combination of laser alloying technology and self-healing materials is an alternative method to improve the hot corrosion resistance of thermal barrier coatings,which is few reported.The purpose of this paper is to study the effect of laser alloying on the microstructure,phase composition,and hot corrosion properties of thermal barrier coatings.Methods In this study,the double-layer thermal barrier coatings of NiCrAlY/8YSZ were deposited onto superalloy substrate via air plasma spraying.The mixture powders of TiAl3particles with 10% mass fraction and Ceria and Yttria-stabilized Zirconia (CYSZ)ceramic were pre-placed on the plasma-sprayed thermal barrier coatings,and then processed using a fiber-coupled semiconductor laser.The mixture of 25% NaCl and 75% Na_(2)SO_(4)as the cor

关 键 词：激光技术 激光合金化 热障涂层 抗热腐蚀性能 自愈合 

分 类 号：TG174.4[金属学及工艺—金属表面处理]