三价铈离子对制冷设备用铝管表面有机-无机杂化膜耐蚀性能的影响

摘要

Organic−inorganic hybrid coating on the surface of aluminum-tube used in refrigeration equipment using cerium ion (III) as the additive was fabricated by sol−gel method, and the structure of the coating was confirmed by FT-IR. The results of the characterization show that the corrosion resistance of the coating with 1.5 mmol/L cerium ion (III) gains significant improvement, in which the colour retention time of CuSO4 extends to 500 s, the anti-acid and alkali corrosion rates reduce by 67% and 70% compared with the blank one, respectively, and the salt spray tests also show good corrosion resistance. The electrochemical tests demonstrate that the self-corrosion current density and potential of the sample with hybrid coating are about 2.877×10−7 A/cm2 and−0.550 V, respectively. The metallographic and SEM images show that the hybrid coating is uniform and dense, and the EDS analysis confirms that the coating is mainly composed of Al, Si and Ce elements.%采用溶胶−凝胶法在制冷设备用铝管表面制备三价铈离子作为添加剂的有机−无机杂化膜，通过傅里叶变换红外光谱确认其结构。性能测试结果表明：当三价铈离子浓度达到1.5 mmol/L时，所得到的杂化膜的耐蚀性能有明显的改善；与空白试样相比，其中CuSO4的变色时间延长到500 s，耐酸和耐碱腐蚀速率分别降低了67%和70%，盐雾试验结果也表现出很好的耐蚀性。电化学测试表明，杂化膜试样的自腐蚀电流密度和自腐蚀电压分别为2.877×10−7 A/cm2和−0.550 V。金相和扫描电镜图片显示杂化膜均匀致密。X射线能谱分析表明该膜层主要由Al、Si和Ce等元素组成。