采用Ni和Al颗粒复合电沉积与后续真空退火的方法，分别于600℃和 800℃退火温度下制备了两种新型细晶Ni3Al涂层。与粗晶合金相比，经1000℃氧化20 h后，合金的氧化层发生大面积剥落，而两种涂层的氧化膜粘附性佳，其主要原因为细晶涂层内的大量晶界促进Al 向氧化前沿的扩散，从而抑制了氧化膜/基体界面处“Kirkendall”孔洞的形成与长大。同时发现，800℃退火涂层氧化膜结构由外至内分别为NiO/NiAl2O4/Al2O3，而600℃退火涂层仅生成NiAl2O4与Al2O3，对该原因进行了探讨。
Fine-grained γ'-Ni3Al coatings were developed by a two-step process: co-electrodeposition of Ni with Al particles and subsequent annealing in vacuum at 600℃ or 800℃. After oxidation at 1000℃ in air for 20 h, the scales formed on both coatings exhibited better adhesion than that on a coarse-grained Ni3Al alloy, because the fine-grained coating structure suppressed the formation of voids at the scale/metal interface. Moreover, the scale formed on the coating by annealing at 800℃ consisted of NiO, NiAl2O4 and Al2O3, while the scale on the coating by annealing at 600℃ consisted of NiAl2O4 and Al2O3. The reason for this result is related to that the latter coating had a finer-grained structure, which promoted rapid formation of a continuum layer of Al2O3.
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