仿生超疏水及耐腐蚀镁合金表面的制备与机理

发布时间：2018-01-13 15:02

  本文关键词：仿生超疏水及耐腐蚀镁合金表面的制备与机理　出处：《吉林大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 镁合金 仿生 超疏水 耐腐蚀性 可逆转换

【摘要】：近年来，由于电子、航空航天、汽车机械制造、高精端仪器设备的快速发展，对有色金属的需求也随之越来越大。而镁合金系列产品由于是有色实用金属中的最轻的金属，具有高比强度、高比刚性，使其具有广阔的应用前景。但是，由于镁具有较高活性，镁合金表面较易耐腐蚀，严重制约了其应用与发展。本文借鉴自然界中典型植物叶表面具有疏水自洁功能，进行了镁合金表面仿生设计，通过激光加工、化学刻蚀、电沉积法等进行了仿生结构超疏水表面的制备，该表面都显示了较好的耐腐蚀性。不仅如此，本论文还基于生物智能调控的原理，，以阳极氧化方法在AZ31镁合金基体制备了超疏水性表面，并对超疏水性及超亲水性的可逆变换进行了试验与机理探索。 本文通过扫描电子显微镜（SEM）、光学接触角测试仪(CA)、X-射线衍射（XRD）、傅立叶红外光谱仪（FTIR）、能谱（EDS）、电化学工作站（CHI）等测试手段，对样品表面的形貌、润湿性、成分、耐腐蚀性等性能进行测试与分析。分析了形态、结构、材料的影响机制，揭示了润湿性、耐腐蚀性、稳定性等功能机理。 运用激光加工结合化学刻蚀的方法制备了仿生超疏水表面。首先采用激光毛化处理机在AZ91D镁合金表面加工出微米级的凹坑，随后经过AgNO3水溶液的化学刻蚀，可以看到明显的纳米级网格状结构，最后在DTS溶液中浸泡修饰，制备出的疏水表面与水接触角达到138.4±2°。通过电化学工作站进行腐蚀性能测试，结果表明制备的AZ91D疏水镁合金表面相比纯AZ91D镁合金表面耐腐蚀性得到明显改善。 运用电化学沉积的方法制备仿生超疏水表面。通过对试样的化学镀预处理以及电化学沉积，在电沉积电流密度为15mA/cm2，时间为3min，电解液浓度为1.0mol/L下制备出具有超疏水性的AZ91D镁合金表面。表面接触角可达到160.8±1°，滚动角仅为1.8±1°，表面具有明显的菜花状微纳米分级结构。通过电化学工作站的腐蚀性测试，结果表明仿生超疏水AZ91D的耐腐蚀性明显提高。又进一步考察了超疏水试样的稳定性，结果表明该试样在pH为2-12范围内具有长期润湿接触角稳定性。 运用阳极氧化法制备了温度调控润湿性的仿生表面。首先采用阳极氧化在AZ31镁合金表面进行氧化处理，随后在硬脂酸溶液中进行浸泡修饰，制备出的超疏水性表面静态接触角达到163.8±1.5°。超疏水性试样在热处理温度低于200℃的范围内，都具有疏水性。当热处理温度达到300℃后，表面从超疏水状态变为超亲水状态，当超亲水后的试样经过再次硬脂酸修饰后，表面润湿性从超亲水状态又转变为了超疏水状态，实现了温度控制润湿性的可逆转换。通过电化学分析，超疏水试样的耐腐蚀性得了明显改善。
[Abstract]:In recent years, due to the rapid development of electronic, aerospace, automotive machinery manufacturing, high-precision instruments and equipment. The demand for non-ferrous metals is also increasing, and magnesium alloy series are the lightest metals in colored practical metals, with high specific strength, high specific rigidity, so it has a broad application prospects. Because of the high activity of magnesium alloy, the surface of magnesium alloy is easy to resist corrosion, which seriously restricts its application and development. In this paper, the bionic design of magnesium alloy surface has been carried out based on the hydrophobic self-cleaning function of typical plant leaf surface in nature. The biomimetic superhydrophobic surface has been prepared by laser processing, chemical etching and electrodeposition. The surface shows good corrosion resistance. Moreover, this paper is based on the principle of intelligent biological regulation. The superhydrophobic surface of AZ31 magnesium alloy was prepared by anodizing method, and the reversibility of superhydrophobicity and superhydrophilicity was investigated. In this paper, a scanning electron microscope (SEM), an optical contact angle tester, an X-ray diffractometer (XRDX), a Fourier infrared spectrometer (FTIR), and an energy spectrum (EDS) have been developed. The morphology, wettability, composition and corrosion resistance of the sample surface were tested and analyzed by electrochemical workstation (Chi). The influence mechanism of morphology, structure and material was analyzed. The functional mechanisms of wettability, corrosion resistance and stability are revealed. The biomimetic superhydrophobic surface was prepared by laser processing and chemical etching. Firstly, micron scale pits were fabricated on the surface of AZ91D magnesium alloy by laser texturing machine. After the chemical etching of AgNO3 aqueous solution, we can see the obvious nanoscale mesh structure, and then immerse it in the DTS solution. The contact angle between the hydrophobic surface and the water was 138.4 卤2 掳. The corrosion performance of the hydrophobic surface was tested by electrochemical workstation. The results show that the corrosion resistance of the surface of AZ91D hydrophobic magnesium alloy is obviously improved compared with that of pure AZ91D magnesium alloy. The biomimetic superhydrophobic surface was prepared by electrochemical deposition. The electroless plating pretreatment and electrochemical deposition were carried out at a current density of 15 Ma / cm ~ (2) and a time of 3 min. The surface of AZ91D magnesium alloy with super hydrophobicity was prepared at the concentration of 1.0 mol / L electrolyte. The surface contact angle was 160.8 卤1 掳and the rolling angle was 1.8 卤1 掳. The surface has obvious rapeseed-like micro-nano-scale structure. The corrosion of the surface is tested by electrochemical workstation. The results show that the corrosion resistance of biomimetic superhydrophobic AZ91D is obviously improved, and the stability of superhydrophobic AZ91D is also investigated. The results show that the sample has a long-term contact angle stability in the pH range of 2-12. The biomimetic surface of wettability controlled by temperature was prepared by anodizing method. Firstly, the surface of AZ31 magnesium alloy was oxidized by anodic oxidation, and then modified by immersion in stearic acid solution. The static contact angle of the superhydrophobic surface was 163.8 卤1.5 掳. The superhydrophobic sample was prepared in the range of heat treatment temperature below 200 鈩

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