热障涂层体系中MCrAlY合金粘接层结构设计及高温氧化行为研究

摘要

本研究旨在通过设计热障涂层体系（TBCs）中合金粘接层的结构以提高TBCs抗氧化性能和热循环使用寿命。研究中采用超音速等离子喷涂（SAPS）沉积不同结构的钴基及镍基合金涂层并对其进行高温氧化性能试验，以此优选涂层结构，并与超音速火焰喷涂（HVOF）沉积的合金涂层进行结构性能对比。结果表明：在高温抗氧化过程中，SAPS涂层中未熔颗粒含量分别为35%±5%的钴基涂层与10%±3%的镍基涂层抗氧化性能最为优异；在相同的合金成分及陶瓷层结构下，SAPS涂层与HVOF涂层相比热循环使用寿命提高了一倍，而热生长氧化物（TGOs）的平均生长速率则降低了20%以上。超音速等离子喷涂可以实现“一步法”制备粘结层和陶瓷层，避免了两步法中间工艺转换过程的二次污染问题，喷涂过程简单，喷涂效率提高，成本大幅降低，具有良好的产业化前景。%This paper aims to improve the anti-oxidation and thermal cycling life of thermal barrier coating system (TBCs) by tailoring the microstructure of MCrAlYbond coat. The cobalt-based and nickel-basedbond coats were deposited byhigh efficiency supersonic atmospheric plasma spraying (SAPS) system. The microstructures of bond coats were optimized by ahigh-temperature oxidation test. A comparative study between SAPS-coating and HVOF-coating (high velocity oxygen fuel spraying, HVOF) was conducted in order to analyze the microstructure-property differences between them. The results showed that the SAPS-coatings that remained 35%± 5%(cobalt-based) and 10%± 3%(nickel-based) unmelted particles exhibited the best oxidation resistance. For the same composition of bond coat and microstructure of top coat, the thermal cycling life of SAPS-coating was two times as much as that of HVOF-coating, however, the average growth rate of thermally grown oxides (TGOs) was reduced by more than 20%. The SAPS can“one-step” deposit the bond coat and top coat , whicheffectively avoids the pollution resulted from the so-called “two-step”process method. With the advantages of simple process, high deposition efficiency and low production cost, the SAPS method shows a good industrial prospect.