镍代钴基高温合金涂层组织及抗氧化性能研究

Study on microstructure and oxidation-resistance of superalloy coating with Ni-base substituting for Co-base

分析了等离子堆焊钴基高温合金Co 0 2、部分镍代钴基合金Co 0 4和镍基代钴基合金NDCo 0 2粉末涂层的金相组织、氧化膜形貌及其能谱、氧化膜断面形貌及其能谱。结果表明 :三种合金涂层的金相组织均为白色奥氏体基体加细小Cr7C3 、Cr7(C ,B) 3 共晶 ;Co 0 2生成Cr2 O3 选择性外氧化保护膜 ,Co 0 4和NDCo 0 2有明显的局部贫Cr区 ,生成CoCr2 O4和NiCr2 O4尖晶石结构保护性氧化膜 ,有效地提高了抗氧化性 ;三种合金均具有优良的抗氧化性能 ,且按NDCo 0 2、Co 0 4、Co 0 2顺序依次增强。评定了它们的抗氧化级别。

Microstructures, morphologies and energy spectrums of oxidated films and their cross sections of plasma sprayed alloy coating Co 02 with Co base, Co 04 whose matrix uses nickel partially instead of cobalt and ND Co 02 with Ni base substituting for Co base were investigated The result indicates that the coatings of these three kinds of alloys are white austenitic base and Cr 7C 3 and Cr 7(C?B) 3 eutectic; Co 02 produces Cr 2O 3 oxidation protection film, and there are distinct areas with shortage of chromium in Co 04 and ND Co 02 coatings where CoCr 2O 4 and NiCr 2O 4 oxidation protection films are produced with spinel structure, which efficiently improved oxidation resistance; these three kinds of alloys have super oxidation resistance which increases in order of ND Co 02,Co 04 and Co 02 The level of oxidation resistance was assessed