整体离子加速器薄膜电阻材料的制备与研究

【作者】 黄冠；

【导师】 何捍卫；

【作者基本信息】 中南大学 ， 粉体材料科学与工程， 2007， 硕士

【摘要】 以石英玻璃管为基体，先是采用化学镀的方法在在非金属材料石英玻璃管上镀上一层Ni—P合金镀层，然后以化学镀Ni-P合金的石英玻璃管为基体，通过复合电沉积的方法获取了在基体表面呈弥散分布的Ni-P-SiO₂复合镀层，可在石英玻璃管表面获得一层具有一定电阻值的薄膜用以制备离子加速器。通过扫描电镜（SEM）、X射线衍射（XRD）、能谱（EDX）等手段对涂层表面形貌、微观结构进行检测，并且使用万用电表和SDHC型数字点式测量仪对表面电阻率进行了分析测量，并通过腐蚀失重测试、极化曲线等手段研究了研究了薄膜材料的腐蚀性能，主要研究内容和结论如下：1)研究了化学镀过程中主要工艺参数（预处理条件、镀液成分、pH值、温度）对涂层金属化过程的影响，对化学镀Ni—P合金镀层的涂层表面形貌、微观结构进行了分析测量。实验结果表明，石英玻璃管表面通过热处理后用镍活化以取代钯活化的方法可行，通过实验可以得出石英玻璃管表面化学镀Ni-P的最佳工艺条件：基体经过预处理后，在pH值为6.5，温度为85℃的镀液中进行化学镀，时间为60min。镀液成分为：NiSO₄·6H₂O：30g／L、NaH₂PO₂·H₂O：30g／L、CH₃COONa·3H₂O：22g／L、C₆H₈O₇：18g／L；2)讨论了复合电沉积中各参数（阴极电流密度，表面活性剂，镀液成分等）与电阻之间的关系，并对涂层表面形貌、微观结构和涂层电阻率进行了检测，实验结果表明，通过复合电沉积的方法可以使得石英玻璃管表面形成具备一定电阻值的电阻薄膜，并且电阻率大小与镀层中二氧化硅含量的成正比关系。随着二氧化硅含量的增加，电阻率可达到5.0×10³μΩ·cm。复合电镀Ni-P／SiO₂的优选工艺为：镀液pH值为3.5～4.0，温度为50～60℃，阴极电流密度为1A／dm²，搅拌速度为700r／min，时间为1h。镀液成分如下：NiSO₄·6H₂O：180g／L；NiCl·6H₂O：40g／L、H₃PO₃：40g／L、H₃PO₄：40mL／L、纳米二氧化硅：5g／L、NaCl：20g／L、柠檬酸：1.5g／L、磺基水杨酸：1g／L、表面活性剂为OP-乳化剂和十六烷基三甲基溴化铵、稳定剂适量；3)研究了电阻薄膜材料在各种腐蚀介质的腐蚀性能和耐腐蚀机理。实验结果显示电阻薄膜材料具有较好的耐蚀性；4)初步研究了化学镀Ni-P过程和复合电沉积Ni／SiO₂过程的机理，认为化学镀镍的氢化物—电化学联合机理能对化学镀Ni—P合金过程中的现象作出较合理的解释；复合电沉积过程则用两步吸附机理进行解释。更多还原

【Abstract】 In order to obtain definite resistance thin films on quartz-glass for ionic accelerator , as the bulk material-quartz-glass tude by electroless Ni-P alloy plating at first, and then adding SiO₂（nanometer）into the plating solution, it can be obtained Ni-P-SiO₂ composite coating of bulk material surface by composite electrodeposition. The surface morphology and microstructure was observed by SEM、XRD、EDX , the surface resistivity was tested by avometer and SDHC digital ,and the corrosion-resisting properties was tested by anodic polarization curves. The mainly conclusions and findings can be summarized as follows: 1) The main processing parameters of electroless plating （pretreatment、content of solution、pH and temperature） were investigated, and the surface morphology and microstructure was observed. The experimental results show that it is a feastble method to substitute palladium activation with nickel activation in quartz-glass tude nickel electroless plating. The electrodepositing solutions and technological parameters of Ni-P alloy coating on quartz-glass tude by electroless plating has been determined through the experimental are decided as follows: NiSO₄·6H₂O:30g/L, NaH₂PO₂·H₂O :30g/L , CH₃COONa·3H₂O:22g/L , C₆H₈O₇ : 18g/L. Temperature-85℃, time-60min and pH value-6．5．2) The main processing parameters of composite electrodeposition （current density and content of solution） were investigated, and the surface morphology, microstructure and the surface resistivity were observed. The results show that the nonconducting quartz-glass tude surface can have definite resistance by composite electrodeposition,and there were derict relation between resistivity and the content of SiO₂．The resistivity can reach to 5．0×10μΩ·cm as the addition of SiO₂ （%）in the coating.The optimum electrodepositing solutions and technological parameters are decided as follows: NiSO₄·6H₂O : 180g/L; NiCl·6H₂O : 40g/L; H₃PO₃: 40g/L; H₃PO₄:40mL/L, SiO₂: 5g/L, NaCl: 20g/L, C₆H₈O₇: 1．5g/L, sulfosalicylic acid: 1g/L, non-ionic and cation surfactants, and so on. 3) The corrosion-resisting properties and mechanism of resistive films were investigated, the results show that the resistive films have fine corrosion-resisting properties. 4) The process of Ni-P alloy coating by electroless plating and composite electrodeposition mechanism were investigated, the hydrid-electrochemistry allied mechanism might be suggested in chemical deposited Ni-P alloy process by combining some results.The process of composite electrodeposition can explain by two step adsorption mechanism.更多还原