谭晓晓,武子雯,孙丹.纳米Al2O3改性β-NiAl涂层的高温氧化行为[J].表面技术,2024,53(24):79-87.
TAN Xiaoxiao,WU Ziwen,SUN Dan.High Temperature Oxidation Behavior of Nano-Al2O3 Modified β-NiAl Coating[J].Surface Technology,2024,53(24):79-87 |
| 纳米Al2O3改性β-NiAl涂层的高温氧化行为 |
| High Temperature Oxidation Behavior of Nano-Al2O3 Modified β-NiAl Coating |
| 投稿时间：2023-12-29 修订日期：2024-07-08 |
| DOI：10.16490/j.cnki.issn.1001-3660.2024.24.007 |
| 中文关键词: 铝化物涂层 复合电镀 退火 互扩散 氧化 纳米颗粒 |
| 英文关键词:aluminide coating electroplating annealing interdiffusion oxidation nanoparticles |
| 基金项目:国家自然科学基金(51501109) |
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| Author | Institution |
| TAN Xiaoxiao | Engineering Training Center,Shanghai 201620, China ;School of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620, China |
| WU Ziwen | School of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620, China |
| SUN Dan | School of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620, China |
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| 中文摘要: |
| 目的 提高铝化物涂层的高温氧化性能。方法 通过在基体上电沉积Ni-Al2O3复合镀层和Ni镀层，随后低温渗铝制备了纳米Al2O3颗粒改性和未改性的δ-Ni2Al3涂层体系。将以上涂层体系在1 000 ℃真空退火10 min，得到纳米Al2O3颗粒改性和未改性的β-NiAl涂层体系。将β-NiAl涂层体系在1 000 ℃进行恒温氧化试验，并通过X射线衍射(XRD)和扫描电子显微镜(SEM)/能谱分析仪(EDS)分析观察铝化物涂层结构和组织形貌在高温下的变化情况。结果 将Al2O3改性和未改性β-NiAl涂层在1 000 ℃恒温氧化20 h，氧化动力学曲线表明，添加纳米Al2O3颗粒后，涂层的氧化增重有所降低。氧化20 h后，两种涂层表面的氧化膜均为α-Al2O3。在XRD探测到的范围内，Al2O3改性β-NiAl涂层退化成了富镍的β-NiAl和γ′-Ni3Al相。而未改性涂层均退化成了γ′-Ni3Al相。从Al2O3改性涂层氧化后的截面形貌可以看到，涂层表面氧化膜致密，与基体结合良好，氧化膜/涂层基体界面和涂层内部存在一些小尺寸空洞。而未改性涂层氧化后表面发生了明显的剥落，其氧化膜未剥落区域的界面处存在尺寸超过5 μm的空洞。结论 纳米Al2O3颗粒的添加可以降低β-NiAl涂层的氧化增重，减小氧化膜/涂层集体界面处的空洞尺寸，进而提高表面热生长氧化膜的黏附性能，导致相同氧化条件下Al2O3颗粒改性涂层的退化程度较轻。 |
| 英文摘要: |
| To improve the high temperature oxidation behavior of the aluminide coating, nano-Al2O3 particles were added and uniformly dispersed in the coating. Al2O3-modified and Al2O3-free δ-Ni2Al3 coating systems were prepared by aluminizing electroplated Ni-Al2O3 and Ni films on Ni substrates at 620 ℃. Accordingly, the two δ-Ni2Al3 coating systems were vacuum annealed at 1 000 ℃ for 10 min to obtain Al2O3-modified and Al2O3-free β-NiAl coating systems. Then, these two β-NiAl coating systems were oxidized at 1 000 ℃ for 20 h. The structures and morphologies of these aluminide coatings before and after oxidation were observed through X-ray diffraction (XRD) and scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS) analysis. After 10 minutes of vacuum annealing at 1 000 ℃, the Al2O3-modified δ-Ni2Al3 coating system degraded to Al rich β-NiAl phases at the depth of XRD detection, while the Al2O3-free coating degraded to Ni rich β-NiAl phases. The cross-sectional morphologies of these two coatings were consistent with the XRD results. The oxidation kinetics curves of the modified and unmodified β-NiAl coating systems at 1 000 ℃ showed that the overall oxidation weight gain of the coating decreased after the addition of nano-Al2O3 particles. According to the difference in oxidation rates, the oxidation process of these two coatings could be divided into two stages:stage Ⅰ with a fast oxidation rate and stage Ⅱ with a slow oxidation rate. There was not much difference in the oxidation rate between these two coatings after entering stage Ⅱ. It was found that the oxidation rate of stage Ⅰ for the Al2O3-modified coating was relatively high compared to the Al2O3-free coating. However, the transition time from stage Ⅰ to stage Ⅱ occurred earlier for the Al2O3-modified coating. Once the oxidation process entered stage Ⅱ, the oxidation rate significantly decreased. After 20 h of oxidation, the oxide scales on surfaces of both coatings were α-Al2O3. The Al2O3-modified coating degraded to Ni rich β-NiAl and γ′-Ni3Al phases, while the unmodified coating completely degraded to γ′-Ni3Al phases within the range detected by XRD. The results showed that the degradation of the coating was reduced after the addition of nano-Al2O3 particles. From the cross-sectional morphology of the Al2O3-modified coating, it was observed that the oxide scale of the modified coating was dense and well-bonded to the substrate after oxidation. Meanwhile, some small-sized cavities were found at the oxide scale/coating interface and inside the coating.However, the surface of the unmodified coating exhibited significant spallation after oxidation and large-sized cavities were found in the spallation area. Cavities exceeding 5 μm also presented at the oxide scale/coating interface where the oxide scale had not peeled off. These observations indicated that the adhesion of the oxide scale was improved after modification with nano-Al2O3 particles. The results above show that the addition of the nano Al2O3 particles can reduce the oxidation rate and increase the oxide adhesion of the aluminide coating, resulting in a lighter degradation of the Al2O3-modified coating under the same oxidation conditions. |
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