用于电子连接器的电沉积及退火纳米晶镍钼合金镀层的耐腐蚀性能研究

发布时间：2023-04-22 07:41

　　电子连接器的可靠性在很大程度上取决于表面涂层的抗腐蚀性能。为了降低表面金保护层的厚度,考虑提高扩散阻挡层的耐腐蚀性能。镍及其合金成本低、易于制备,并且在酸性条件下和含有氯离子的腐蚀介质中具有优异的耐腐蚀性。电沉积是合成具有可调节晶粒尺寸和结构的纳米晶镍合金镀层的方法。然而,纳米晶镍基材料的机械性能和腐蚀性能可能由于原子的扩散和晶粒尺寸的粗化而下降。此外,当晶粒尺寸小于30nm时,晶界的不稳定性可能导致耐腐蚀性能下降。因此本课题研究在适当温度下对镍钼合金进行退火处理从而稳定晶界,通过直流电沉积制备纳米晶镍钼合金涂层,并在高温下进一步退火。通过SEM,EDS,XRD和XRF分别表征了镍钼镀层的表面形貌、化学组成、晶体结构和厚度,并采用电化学测试来研究镀层的抗腐蚀性能。主要结果如下:(a)通过改变镀液的组成来调节镀层中的钼含量,结果表明沉积的镍钼镀层的钼含量对表面形态和腐蚀行为起主要影响。晶粒尺寸随着钼含量的增加而减小,但“颗粒”尺寸增大。在这种情况下,随着钼含量增加,抗腐蚀性降低。此外,在1M硫酸中观察到样品的钝化行为,而在3.5wt%氯化钠中没有发生明显的钝化。(b)研究了电流密度对耐腐...

【文章页数】：75 页

【学位级别】：硕士

【文章目录】：
摘要
abstract
CHAPTER1 INTRODUCTION
    1.1 Research background
    1.2 Electrical connector
        1.2.1 Structure,function and materials of electrical connector
        1.2.2 Failures of Connectors
        1.2.3 Coatings for connector
    1.3 Surface functional materials for connectors
        1.3.1 Tin
        1.3.2 Nickel
        1.3.3 Ni-based alloys
    1.4 Research propose
CHAPTER2 EXPERIMENTAL METHODS AND CHARACTERIZATION DEVICES
    2.1 Materials and process for experiments
        2.1.1 Chemicals and materials for experiments
        2.1.2 Electrodeposition of Ni-Mo alloys
        2.1.3 Heat-treatment device
        2.1.4 Electrochemical characterization device
    2.2 Materials characterizations
        2.2.1 Field emission scanning electron microscope(FESEM)
        2.2.2 Energy dispersive X-ray spectroscopy(EDS)
        2.2.3 X-ray fluorescence thickness gauge(XRF)
        2.2.4 X-ray diffractometer(XRD)
    2.3 Electrochemical characterization
        2.3.1 Electrochemical Impedance Spectroscopy
        2.3.2 Polarization test
CHAPTER3 CORROSION RESISTANCE OF NI-MO ALLOY COATING WITH DIFFERENT MO CONTENT
    3.1 The preparation of Ni-Mo alloys
    3.2 Characterizations of as-deposited Ni-Mo coatings
    3.3 Anti-corrosion behavior of Ni-Mo coatings
        3.3.1 Anti-corrosion behavior of as-deposited Ni-Mo coatings in3.5wt%NaCl··
        3.3.2 Anti-corrosion behavior of as-deposited Ni-Mo coatings in1M H2SO
    3.4 Conclusion
CHAPTER4 EFFECT OF CURRENT DENSITY ON THE CORROSION BEHAVIOR OF NI-MO COATINGS
    4.1 The preparation of Ni-Mo alloys
    4.2 Characterizations of Ni-Mo coatings
    4.3 Electrochemical analysis of Ni-Mo coatings
    4.4 Conclusion
CHAPTER5 CORROSION BEHAVIOR OF AS-ANNEALED NI-MO COATINGS
    5.1 Thermal treatments
    5.2 Characterizations of as-annealed Ni-Mo coatings
    5.3 Anti-corrosion measurements of as-annealed Ni-Mo coatings
    5.4 Conclusion
CHAPTER6 SUMMARY
REFERENCES
致谢



本文编号：3797212