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β-NiAl是一种有前景的应用于1150°C以上的抗氧化涂层材料。本文利用电子束物理气相沉积(EB-PVD)方法制备了0~0.5at%Dy含量的β-NiAl涂层,研究了涂层的瞬态氧化行为。1200°C时,在0.05at%Dy掺杂的涂层中只观察到了稳态α-Al2O3相,而在0.5at%Dy掺杂的涂层中,1h氧化过程中,发生了θ-Al2O3到α-Al2O3的相变。1100°C时,在最初的15min所有涂层均发生了θ-α相变。0.05at%Dy掺杂的涂层在45min的时候相变已经完成,这比0.5at%Dy掺杂涂层要早得多。过量Dy的掺杂能够延缓θ-α相变。未掺杂和过量掺杂涂层在20h氧化之后仍存在针状相θ-Al2O3,而0.05at%Dy掺杂的涂层中则为经典的颗粒状α-Al2O3形貌。
β-NiAl is a promising antioxidant coating material for applications above 1150 ° C. In this paper, the β-NiAl coating with 0 ~ 0.5at% Dy content was prepared by electron beam physical vapor deposition (EB-PVD) method, and the transient oxidation behavior of the coating was studied. At 1200 ° C only the steady-state α-Al 2 O 3 phase was observed in the 0.05 at% Dy-doped coating whereas in the 0.5 at% Dy-doped coating, θ-Al 2 O occurred during 1 h of oxidation α-Al 2 O 3 phase transformation. At 1100 ° C, θ-α transformation occurred in all coatings during the first 15 min. The 0.05 at% Dy-doped coating has been completed at 45 min, much earlier than the 0.5 at% Dy-doped coating. Excess Dy doping can delay the θ-α phase transition. The undoped and overdoped coatings still present the acicular phase θ-Al 2 O after 20 h of oxidation, whereas the 0.05 at% Dy-doped coatings are typical of the granular α-Al 2 O 3 morphology.