超音速颗粒轰击处理对MCrAlY涂层氧化行为的影响

Effect of supersonic fine particles bombarding on oxidation behavior of MCrAlY coating

摘要: 采用等离子喷涂(atmospheric plasma spraying,APS)技术在镍基高温合金(GH99)上沉积MCrAlY粘结涂层,并进行超音速颗粒轰击处理。研究超音速颗粒轰击工艺对MCrAlY涂层高温氧化性能的影响。利用扫描电镜、X射线衍射仪、辉光光谱仪对涂层的氧化物演化过程进行观察和分析。结果表明,表面超音速颗粒轰击处理后,涂层表面所生成的氧化物较细小,能快速形成致密连续的氧化膜,保护了粘结层中其它元素的进一步氧化,避免了Ni(Cr,Al)₂O₄等大颗粒氧化物的形成,延缓了涂层中裂纹的产生和扩展,有效地改善了涂层抗高温氧化性能。

Abstract: MCrAlY bonding coating was deposited on GH99 high-temperature alloy using atmospheric plasma spraying(APS). The influence of supersonic fine particles bombarding on microstructure and thermally grown oxide of MCrAlY coating was investigated, and the interface, phase constituents and the evolution of the coating exposed at 1 100℃ for different times was evaluated by SEM, XRD and glow discharge spectroscopy.The experimental results showed that the oxide particles were fine through supersonic treating, then Al₂O₃ scale formed quickly onMCrAlY surface, and Ni and Cr were prevented from oxidizing.For this reason, the formation of Ni(Cr,Al)₂O₄ can be avoided and flaw decreases, so that the high-temperature oxidation resistance of coating is improved.