LaZrCeO热障涂层EB-PVD制备及失效机理  

Preparation and failure mechanism of LaZrCeO thermal barrier coating by EB-PVD

作　　者：罗宇晴 李子楠 朱石刚 何利民 宇波 王玉峰 LUO Yuqing;LI Zinan;ZHU Shigang;HE Limin;YU Bo;WANG Yufeng(Surface Engineering Division,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Air Force Armament Department,Xi’an 710021,China;AECC Aviation Power Co.,Ltd.,Xi’an 710021,China)

机构地区：[1]中国航发北京航空材料研究院表面工程所,北京100095 [2]空军装备部,西安710021 [3]中国航发动力股份有限公司,西安710021

出　　处：《材料工程》2024年第12期53-60,共8页Journal of Materials Engineering

基　　金：国家科技重大专项项目(J2019-Ⅶ-0010-0150);海装预研基金项目(30204);国家自然科学基金项目(52202073)。

摘　　要：热障涂层作为一种由金属黏结层、陶瓷面层和热生长氧化物组成的防护涂层,在航空发动机涡轮叶片上得到了广泛的应用。采用电子束物理气相沉积技术在Ni基高温合金基体上制备LaZrCeO/YSZ双陶瓷热障涂层。通过调控靶材的沉积能量,研究热障涂层成分、相结构及热循环寿命。分析了1100℃热循环下热障涂层失效机理。结果表明,随着靶材沉积能量增大,LaZrCeO涂层中Zr元素含量不断增加,而La/Ce元素比与靶材基本保持一致。同时,随着靶材沉积能量增大,涂层相结构由单一萤石相转变为复合烧绿石和萤石相结构,再转变为单一烧绿石结构。1100℃热循环测试表明,具有复合烧绿石和萤石相结构的LaZrCeO/YSZ双陶瓷热障涂层平均热循环寿命为1518次,表现出较好的热物理性能。随着热循环的进行,金属黏结层中的Al元素向外扩散,形成热生长氧化物(TGO),Cr元素与LaZrCeO和O反应,形成了LaCrO_(3)和ZrO_(2)。Ni元素和Co元素在高温下扩散并与O反应,形成(Ni,Co)(Cr,Al)_(2)O_(4)化合物,使得TGO层或界面层产生裂纹,降低了金属黏结层和陶瓷层之间的韧性,最终导致热障涂层失效。Thermal barrier coatings,consisting of a metal bonding layer,ceramic surface layer,and thermal growth oxide,are widely utilized in turbine blades for aero engines as protective coatings.The LaZrCeO/YSZ double ceramic thermal barrier coating was prepared on a Ni-based superalloy matrix using EB-PVD technology.The composition,phase structure,and thermal cycle life of the thermal barrier coating were investigated by adjusting the deposition energy of the ingot.Furthermore,the failure mechanism of the thermal barrier coating under 1100℃thermal cycle was analyzed.The results indicate that the Zr content in the LaZrCeO coating increases proportionally with the rise in ingot deposition energy,while maintaining a consistent La/Ce ratio.Additionally,the increase in evaporation electron beam leads to changes in coating phase structure from single fluorite phase to compound pyrochlore and fluorite phase structure,and finally to single pyrochlore structure.Thermal cycling tests at 1100℃demonstrate that the average thermal cycle life of LaZrCeO/YSZ ceramic thermal barrier coating with composite pyrochlore and fluorite phase structure reaches 1518 cycles,indicating excellent thermal physical properties.As the thermal cycle progresses,the Al element in the bond coat diffuses outward to form a thermally grown oxide(TGO)layer,while the Cr element reacts with LaZrCeO and oxygen to generate LaCrO_(3)and ZrO_(2).At elevated temperatures,Ni and Co elements diffuse and react with oxygen to produce(Ni,Co)(Cr,Al)_(2)O_(4)compounds.The chemical reactions induce cracks in either the TGO layer or the interface layer,reducing the toughness between the metal bond layer and ceramic layer,and leading to thermal barrier coating failure.

关 键 词：热障涂层 电子束物理气相沉积 相结构 元素含量 热循环寿命 失效机理 

分 类 号：TB33[一般工业技术—材料科学与工程] TG174.453[金属学及工艺—金属表面处理]