Effect of Chemical Compositions and Surface Morphologies of MCrAlY Coating on Its Isothermal Oxidation Behavior
Effect of Chemical Compositions and Surface Morphologies of MCrAlY Coating on Its Isothermal Oxidation Behavior
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DOI：
10.1007/s11666-010-9590-0
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发表时间：
2011-01-01
影响因子：
3.1
通讯作者：
Yang, Guan-Jun
中科院分区：
文献类型：
--
作者：
Li, Yong;Li, Chang-Jiu;Yang, Guan-Jun
MCrAlY涂层的化学成分和表面形貌是影响热障涂层氧化行为和耐热性的因素。采用冷喷涂Ni20Cr10AlY和Ni23Co20Cr8.5Al4.0Ta0.6Y两种抛光涂层，研究了成分对涂层氧化行为的影响。采用冷喷涂和喷丸表面处理的MCrAlY涂层，以及表面结合较弱的低压等离子喷涂MCrAlY涂层，研究了表面形貌对MCrAlY涂层氧化行为的影响。在快速生长阶段，冷喷涂Ni20Cr10AlY涂层表现出两阶段氧化行为，TGO生长速率高于冷喷涂Ni23Co20Cr8.5Al4.0Ta0.6Y涂层。氧化10h后，冷喷涂涂层表面的TGO主要由Al_2O_3组成，而溅射涂层表面的TGO主要由Al_2O_3和Cr/Ni氧化物组成。经500h氧化处理后，不同成分的冷喷涂涂层表面的氧化层中出现了Cr2O3和多孔尖晶石。Cr/Ni氧化物的生长归因于Al的贫化。经喷丸处理的冷喷涂NiCrAlY涂层的尖晶石含量较未喷涂层减少。
Chemical composition and surface morphology of MCrAlY coatings are factors which influence the oxidation behavior and the thermal durability of thermal barrier coatings. In this study, Cold-sprayed Ni20Cr10AlY and Ni23Co20Cr8.5Al4.0Ta0.6Y coatings with polished surfaces were employed to study the effect of composition on the oxidation behavior. The cold-sprayed MCrAlY coatings at the as-sprayed and shot-peened surface conditions, along with the low pressure plasma-sprayed MCrAlY coating with sputters adhered weakly on the surface, were employed to investigate the effects of surface morphologies of MCrAlY coatings on their oxidation behavior. Cold-sprayed Ni20Cr10AlY coating exhibited a two-stage oxidation behavior and a higher TGO growth rate than that of the cold-sprayed Ni23Co20Cr8.5Al4.0Ta0.6Y coating at the rapid growth stage. After 10-h oxidation, the TGO on the as-cold-sprayed coating surface was mainly constituted by Al2O3, while the TGO on the coating surface attached with sputters was composed of Al2O3 and Cr/Ni-oxides. After 500-h oxidation, Cr2O3 and porous spinel appeared in the TGO on the surface of the as-cold-sprayed coatings with different compositions. The growth of Cr/Ni-oxides was attributed to the Al depletion. The content of spinel decreased on the cold-sprayed NiCrAlY with a shot-peened surface compared with the as-sprayed coating.