(1. 中南大學 材料科學與工程學院，長沙 410083；
2. 廣西大學 材料科學與工程學院，南寧 530004；
3. 中國科學院 金屬研究所 金屬腐蝕與防護國家重點實驗室，沈陽 110016)
摘 要: 用空氣緩冷和水快冷方式對加熱至1 050 ℃的NiCrAlY單一涂層及含CrON擴散阻擋層的復合涂層冷卻至室溫，由此研究其抗循環(huán)氧化能力。結果表明：在緩冷情況下，經(jīng)過200次循環(huán)氧化，無擴散阻擋層的NiCrAlY涂層明顯退化，表面膜呈疏松多孔結構，以混合氧化物相為主，在涂層與基體界面附近出現(xiàn)Kirkendall孔穴；有擴散阻擋層的試樣表面則以Al2O3膜為主，擴散阻擋層保持連續(xù)，無明顯涂層退化或破壞現(xiàn)象，說明擴散阻擋層能明顯提高NiCrAlY涂層的緩冷抗循環(huán)氧化能力。在快冷情況下，有或無擴散阻擋層的試樣的表面涂層均較快發(fā)生破壞。40次循環(huán)氧化后，單一涂層表面出現(xiàn)鼓包突起；45次循環(huán)氧化后，鼓包處涂層脫落。而有擴散阻擋層的試樣經(jīng)40次循環(huán)氧化后于擴散阻擋層界面處開裂；45次循環(huán)氧化后，包覆涂層部分斷落。利用Oxx公式能很好地解釋涂層/基體或涂層/擴散阻擋層界面的破壞；對于快冷循環(huán)氧化，還要考慮在循環(huán)過程中的熱應力累積效應。
關鍵字: NiCrAlY涂層；擴散阻擋層；循環(huán)氧化；界面；失效機理
（1. School of Material Science and Engineering, Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering, Guangxi University, Nanning 530004, China;
3.）
Abstract:The cycled oxidation resistance abilities of single NiCrAlY coated sample and NiCrAlY/CrON duplex coating sample were studied by cooling from 1 050 ℃ to room temperature in air and water quenching. The results show that during slow cooling, the single NiCrAlY coating degrades after 200 cycles, with mixed-oxides of Al2O3, NiCr2O4 and TiO2 on the surface and Kirkendall voids formed closing to the NiCrAlY/DSM11 interface. On the surface of duplex coating sample with the diffusion barrier layer, an adhered Al2O3 scale is formed and no damage is detected at the coating/substrate interface. In the case of fast cooling, the two coating samples are fast damaged only after some cycles. After 40 cycles, some bulges are found on the single coating surface, and the interfacial delamination occurs in the duplex coating sample. After 45 cycles, the coatings in the bulge zone are spalled off from the single coated sample, while part of the overlayer is fractured in the duplex coating sample. By Oxx formula, the thermal stress formed during cycled oxidations can be used to explain the interfacial damage or coating failure, and the cumulative effects of stress should be considered during rapid cooling in water quenching.
Key words: NiCrAlY coating; diffusion barrier; cycled oxidation; interface; failure mechanism
