HCPEB表面改性对镀铝CoCrAlY涂层显微组织及氧化性能的影响  

Impact of HCPEB Surface Modification on Microstructure and Oxidation Properties of Aluminized CoCrAlY Coating

作　　者：韩志勇 史文新 王者 丁坤英 程涛涛 HAN Zhiyong;SHI Wenxin;WANG Zhe;DING Kunying;CHENG Taotao(Tianjin Key Laboratory for Civil Aircraft Airworthiness and Maintenance,Civil Aviation University of China,Tianjin 300300)

机构地区：[1]中国民航大学天津市民用航空器适航与维修重点实验室

出　　处：《材料导报》2019年第14期2392-2396,共5页Materials Reports

基　　金：国家自然科学基金(51501222);中央高校基本科研业务费中国民航大学理学专项项目(3122016L013)~~

摘　　要：利用大气等离子喷涂技术在镍基高温合金基体上制备CoCrAlY涂层,使用EBVD技术蒸镀纯铝薄膜,并利用强流脉冲电子束改性镀铝涂层,通过改变轰击次数以达到改变入射能量的目的。将轰击后的镀铝涂层进行高温氧化实验,观察并分析轰击后镀铝涂层的氧化行为以及显微形貌的变化,研究HCPEB脉冲次数对涂层表面相成分的影响。与APS喷涂涂层相比,改性涂层的氧化动力学曲线更趋近于抛物线,且在氧化后期增重缓慢。XRD结果显示,经不同次数轰击后的涂层相成分基本一致,累计脉冲次数越多,α-Al2O3含量越高。SEM结果显示,经HCPEB轰击后的涂层的表面重熔,形成细胞状凸起结构。经30次轰击后的改性涂层表面氧化0.5h后,出现氧化铝和Co/Cr-O类氧化物;氧化20h后生成横向连续致密的α-Al2O3膜;氧化100h后,在小范围内生成尖晶石类氧化物,α-Al2O3膜仍起保护作用。CoCrAlY coating was prepared on Ni-base superalloy substrate by atmospheric plasma spraying(APS)technology.Then pure aluminum film was evaporated on CoCrAlY coating by EBVD technology,and finally the modification of pure aluminum film was carried out by high-current pulsed electron beam(HCPEB)with various incident energy changed by changing the bombardment times.The high-temperature oxidation resistance test of aluminized CoCrAlY coating was conducted under isothermal conditions.The surface microstructure and oxidation behavior of aluminized coating after HCPEB bombardment were observed,and the effect of HCPEB bombardment times on the surface phase composition of the coating was studied.Compared with APS sprayed coating,the oxidation kinetic curve of the modified coating was closer to the parabola,and the weight increment was slow at the later period of oxidation.XRD results revealed that the phase composition of the coating after bombardment was basically the same no matter how many bombardment times would be.The more bombardment pulse times brought about higherα-Al2O3 content.SEM characterization results showed that the surface of modified coating was remelted and formed interconnected cell-like raised structures.Al2O3 and Co/Cr-O oxides began to appear after 0.5 h oxidation.After 20 h oxidation,lateral continuous denseα-Al2O3 films were formed.After 100 h oxidation,spinel oxides were generated in a small range,and theα-Al2O3 film still had a protective effect.

关 键 词：热障涂层 强流脉冲电子束 热生长氧化物 氧化行为 相组成 显微形貌 

分 类 号：TG154.5[金属学及工艺—热处理]