Y2O3/CeO2改性的低温渗铝涂层制备和循环氧化性能研究

Fabrication and cyclic oxidation of Y2O3/CeO2-modified low temperature aluminide coatings

摘要:

本文利用Y2O3/CeO2纳米颗粒替代部分Al2O3粉作为填充剂，在Ni基体上, 600℃低温渗铝10h，制备了Y2O3/CeO2改性的低温渗铝涂层。作为对比，采用相同的工艺在Ni基体上利用纯Al2O3粉制备了普通渗铝涂层。对比研究了Y2O3/CeO2是如何影响氧化铝的相变以及渗铝涂层的1000℃时的循环氧化性能。结果发现，Y2O3和CeO2对q-a相变具有不同的作用：Y2O3抑制?-Al2O3的长大，而CeO2促进?-?相变。与普通渗铝涂层相比，Y2O3/CeO2改性的渗铝涂层形成粘附性更好的氧化铝膜，提高了渗铝涂层的循环氧化性能。文中对Y2O3/CeO2是如何影响?-?相变以及渗铝涂层的循环氧化性能进行了分析。

Abstract:

By using Y2O3/CeO2 powder, instead of part of Al2O3, acting as filler, Y2O3/CeO2-modified aluminide coatings were produced on Ni based using a conventional pack-cementation method at 600℃ for 10 h. For comparison, normal aluminide coating was also produced using pure Al2O3 acting as filler. Effect of Y2O3/CeO2 in the pack on the alumina phase transformation and cyclic oxidation resistance in air at 1000℃ was investigated. The results indicated that Y2O3 and CeO2 have a different effect for ?-? phase transformation: Y2O3 suppresses the growth of the ?-alumina but CeO2 promotes the q-a phase transformation. However, compared to the normal aluminide coatings, the addition of Y2O3/CeO2 significantly improved the cyclic oxidation resistance due to the formation of adherent alumina scale, especially the later. The effects of Y2O3 /CeO2 on alumina phase transformation and cyclic oxidation resistance are discussed in detail.