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采用电弧离子镀技术及后续热处理工艺在镍基高温合金上制备了均匀NiCrAlY涂层和梯度NiCrAlY涂层,分析了2种涂层的组织结构,对比研究了2种涂层静态空气下1000和1100℃恒温氧化行为以及1100℃的循环氧化行为.结果表明:均匀NiCrAlY涂层由γ′/γ相和少量β-NiAl相、α-Cr相组成,成分分布均匀;梯度NiCrAlY涂层具有外层富Al和内层富Cr的结构,其中外层由β-NiAl相和少量γ′/γ相、α-Cr相组成.一方面,梯度涂层的初始Al含量较高;另一方面,氧化过程中其富Cr区两侧出现了对富Al区的Al向基体扩散起阻碍作用的Cr(W)析出带.这两方面使梯度涂层长时间维持更多的Al存储相,提升了氧化膜的迅速生成及再生成能力,从而使涂层具有较好的抗氧化性能.
The uniform NiCrAlY coating and gradient NiCrAlY coating were prepared on the Ni-based superalloy by arc ion plating and subsequent heat treatment. The microstructures of the two coatings were analyzed. The microstructures of the two coatings were compared under static air conditions of 1000 and 1100 ℃ and cyclic oxidation at 1100 ℃ .The results show that the uniform NiCrAlY coating is composed of γ ’/ γ phase and a small amount of β-NiAl phase and α-Cr phase, Al and the inner layer is rich in Cr, the outer layer is composed of β-NiAl phase and a small amount of γ ’/ γ phase and α-Cr phase .On the other hand, the initial Al content of gradient coating is higher; on the other hand, In the Cr-rich region on both sides of the Al-rich region of Al to the substrate diffusion barrier from the role of Cr (W) precipitation zone, both of which make the gradient coating to maintain more Al storage phase for a long time to enhance the oxide film The rapid generation and regeneration ability, so that the coating has good oxidation resistance.