| 摘要: |
| 随着我国“海洋强国”战略目标日益推进，舰船表面使用的铝合金部件面临着海洋腐蚀的风险。为进一步提升铝合金的耐腐蚀性能，增长其使用寿命，通过爆炸喷涂技术于铝合金基体上制备 AlCuFe 和 AlCuFeSc 准晶涂层，借助扫描电子显微镜（SEM）、X 射线衍射仪（XRD）表征准晶粉末及涂层的微观及物相组织结构，进一步利用拉伸试验机、电化学工作站等分析涂层的结合力及耐蚀性能，研究准晶相含量与涂层耐蚀性能间的影响规律。结果表明，爆炸喷涂制备的 AlCuFe 和 AlCuFeSc 涂层致密度高且与基体结合良好，结合强度分别为 51.9 MPa、51.2 MPa。经 700 ℃退火处理后的涂层准晶相含量分别由 49%、38%提升至 93.2%、92.5%。退火前的准晶涂层耐腐蚀性能与基体相近，退火后的准晶涂层自腐蚀电流密度仅为铝合金基体的 1 / 5，证明准晶相含量提升增强了涂层的耐蚀性能。同时盐水静态挂片测试 336 h 后，退火处理的涂层表面未生成明显的腐蚀区域，准晶相含量提升促使表面生成的氧化铝钝化层为基体提供了良好的保护，研究可以为未来舰船使用铝合金表面的腐蚀防护提供新思路，同时也可为铝基准晶涂层的制备应用提供研究基础。 |
| 关键词: 铝合金 准晶涂层 爆炸喷涂 电化学 盐水腐蚀 |
| DOI：10.11933/j.issn.1007-9289.20230315002 |
| 分类号:TG174 |
| 基金项目: |
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| Influence Mechanism of the Quasicrystalline Phase Content on the Corrosion Resistance of AlCuFe-based Coatings |
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LI Wei1, ZHANG Yuxin1, YU Ang1, JIN Guo2, WANG Hao2
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1.School of Mechanical Technology, Wuxi Institute of Technology, Wuxi 214121 , China;2.College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 , China
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| Abstract: |
| Considering the development of China’s strategic goal of “ocean power”, aluminum alloy components, such as the deck and keel used on the ship surface, face the risk of corrosion failure during long-term service. Currently, the method of preparing a film or coating on the surface of aluminum alloys is typically used to isolate the corrosive medium and effectively protect the matrix material. Among these, thermal spraying technology is widely used for the preparation of anti-corrosion coatings on the surface of aluminum alloys owing to its simple operation and because it is not limited by the size of the parts. Aluminum reference crystal materials have a high strength and hardness owing to their unique structure and excellent properties such as a low friction and corrosion resistance. Thus, they have high potential as protective coating materials on the surface of a new generation of aluminum alloys; however, the poor bonding strength and corrosion resistance in the preparation of quasicrystalline (QC) coatings limit their application. Therefore, in this study, AlCuFe and AlCuFeSc QC coatings are prepared on aluminum alloy substrates using explosive spraying technology based on the long-term service conditions of aluminum alloy parts in a marine environment to improve the corrosion resistance of aluminum alloys and increase their service life. First, the microstructures and phase structures of the powder and coating are characterized using scanning electron microscopy and X-ray diffraction. Subsequently, the binding force and corrosion resistance of the coating are analyzed using a tensile testing machine and electrochemical workstation, and the influence of the QC phase content and corrosion resistance of the coating are studied. The tests reveal that the powder and coating are composed of a Ⅰ-Al65Cu20Fe15 QC phase and small amount of the β-AlFe phase. The AlCuFe and AlCuFeSc coatings prepared by explosive spraying have a high density and demonstrate good bonding with the substrate; the bonding strengths of the coatings are determined to be 51.9 MPa and 51.2 MPa, respectively. After annealing at 700 ℃, the content of the coating QC phase increases from 49%, 38% to 93.2%, 92.5%, respectively. In addition, the corrosion resistance of the QC coating before annealing is similar to that of the substrate,and the self-corrosion current density of the annealed QC coating is only one-fifth of that of the aluminum alloy substrate. A further comparison of the surface morphologies of the coatings with different QC contents reveales that as the QC content increases, the flatness of the coating surface increases and the pore distribution decreases, which can effectively prevent the entry of corrosive media. This suggests that an increase in the QC content enhances the corrosion resistance of the coating. The salt-water static hanging test simultaneously demonstrates that no apparent corrosion area formes on the annealed coating surface after 336 h, and the aluminum oxide passivating layer that forms on the surface provides a good protection for the substrate as the content of the QC phase increases. The stability of the QC phase I improves by the introduction of the Sc element into the Al-Cu-Fe icosahedron. This study provides a new idea for the corrosion protection of aluminum alloy surfaces used in ships and a basis for the preparation and application of aluminum reference crystal coatings. |
| Key words: aluminum alloy quasicrystalline coating explosive spraying electrochemistry salt water corrosion |
