【作者】 张智贤；

【导师】 王宏智；

【作者基本信息】 天津大学 ， 应用化学， 2010， 硕士

【摘要】 电沉积Ni-Sn-P合金镀层具有良好的耐蚀性、焊接性、延展性、结合力和易修复性,在工业上有着广泛的应用前景,且由于其具有典型、系统的腐蚀过程,可作为研究腐蚀系统的模型。因此,电沉积Ni-Sn-P合金镀层的研究具理论研究意义和重要使用价值。本文首先利用电化学方法和腐蚀失重方法研究了不同Sn、P含量Ni-Sn-P合金在10%H₂SO₄溶液和人工海水中的腐蚀性能,并利用SEM、XPS、XRD及EDS分析了合金的晶体结构和腐蚀产物。研究结果表明:高Sn含量的Ni-Sn-P在10%H₂SO₄溶液和人工海水中的耐蚀性优于化学镀Ni-P合金和SUS304不锈钢,其耐蚀性随着合金中Sn元素含量的增加而逐渐提高;Ni-Sn-P合金在10%H₂SO₄溶液中发生均匀腐蚀,Ni元素优先溶解,Sn、P元素在合金表面富集,形成一层由SnO₂、Ni₃（PO₄）₂组成的钝化膜;Ni-Sn-P合金在人工海水中发生均匀腐蚀,Ni、Sn元素优先溶解,P元素在合金表面富集,形成一层由SnO₂、Ni₃（PO₄）₂、NiO和Ni₂O₃组成的钝化膜,其中SnO₂能很好的抵御人工海水中氯离子的穿透效应。在此基础上,本文研究了热处理的温度和所处的气氛对Ni-Sn-P合金耐蚀性的影响。实验结果表明,在氮气气氛下热处理的Ni-Sn-P合金在10%H₂SO₄溶液中的耐蚀性随着热处理温度的提高而降低;合金在人工海水中的腐蚀行为与在硫酸中不同,低温热处理的合金在人工海水中的耐蚀性有所提高,随着温度升高,合金的耐蚀性逐渐降低。但是当热处理温度为500℃的时候,合金在人工海水中的耐蚀性出现了明显的提高。在空气气氛下,低温（200℃、300℃）热处理会降低Ni-Sn-P合金的耐蚀性,高温（400℃、500℃）热处理会使合金表面生成一层由SnO、SnO₂、NiO、Ni₂O₃和P₂O₅组成的氧化膜,阻碍腐蚀介质与合金的接触,对合金起到保护作用,从而提高合金的耐蚀性。更多还原

【Abstract】 Ni-Sn-P alloy coating has been widely applied in the industries because it has good properties in corrosion resistance conductivity and reparability, etc. And as its corrosion process is typical and systemic, it has been usually used as the model to study the corroding system. So it is valuable to study the Ni-Sn-P alloy coating.In this paper, the electrochemical methods and corrosion weight loss methods were used to research the corrosion resistance of Ni-Sn-P alloy coating in 10%H₂SO₄ and artificial sea water. SEM, XPS, XRD and EDS were used to analyze the crystal structure and corrosion products of Ni-Sn-P alloy coating.Results of the study have shown that Ni-Sn-P alloy coating with high content of Sn has batter corrosion resistance than Ni-P alloy coating and SUS304 stainless steel, and the corrosion resistance of Ni-Sn-P alloy improved as the Sn content increased.In 10%H₂SO₄, the uniform corrosion can take place on the surface of Ni-Sn-P alloy coating. The element of Ni dissolved preferentially, with the element of P, Sn enriched on the surface of Ni-Sn-P alloy coating. As a result of this, a layer of passive film composed of SnO₂ and Ni₃（PO₄）₂ formed on the surface of Ni-Sn-P alloy, which can protect the alloy from corrosion. In artificial sea water, also the uniform corrosion can take place on the surface of Ni-Sn-P alloy coating. But the element of Ni and Sn dissolved preferentially, with the element of P enriched on the surface of Ni-Sn-P alloy coating. Then a layer of passive film composed of SnO₂、Ni₃（PO₄）₂、NiO and Ni₂O₃ formed on the surface of Ni-Sn-P alloy, of which, SnO₂ can resist the penetration effect of Cl- effectively.Besides of this, we have researched the influence of heat treatment with different atmosphere and temperatures on the corrosion resistance of Ni-Sn-P alloy coating. The results have shown that as the heat treatment temperature increased in nitrogen atmosphere, the corrosion resistance of Ni-Sn-P alloy coating in 10%H₂SO₄ was reduced. In artificial sea water, the corrosion resistance of Ni-Sn-P alloy coating was improved with low temperature （200℃） heat treatment, and then as the heat treatment temperature increased, its corrosion resistance reduced. But when the heat treatment temperature was 500℃, the corrosion resistance of Ni-Sn-P alloy coating was improved effectively.The corrosion resistance of Ni-Sn-P alloy coating was reduced with low-temperature （200℃, 300℃） heat treatment in air atmosphere; But high-temperature （400℃, 500℃） heat treatment in air atmosphere will lead to a layer of thick and dense oxide film composed of SnO, SnO₂, NiO, Ni₂O₃ and P₂O₅ formed on the surface of Ni-Sn-P alloy coating, which can separate the corrosive solution and the Ni-Sn-P alloy, protecting the alloy from corrosion.更多还原