不锈钢表面电镀Pd-Ni基高耐蚀性膜层
发布时间：2019-05-19 00:03
【摘要】：钯镍(Pd-Ni)合金由于其相对较低的成本与优异的综合性能,在装饰,电接触材料,电催化,有机合成等领域被广泛研究与应用。本文首先开发了 Pd-Ni合金膜电镀工艺,在其基础上,通过电镀的方式分别在316L不锈钢表面制备了 Pd-Ni/TiO2复合镀层与Pd-Ni-W三元合金镀层两种镀层。主要通过电化学方法研究了镀层的耐蚀性能与机理。通过XRD、SEM、EDS、GODES等方法对镀层的形貌和结构进行表征,并且讨论了其与耐蚀性能之间的关系。具体研究如下:(1)在316L不锈钢表面,通过直流电镀的方法分别制备了 Pd-Ni合金镀层与Pd-Ni/TiO2复合镀层镀。电化学测试结果表明:Pd-Ni/TiO2复合镀层在60℃的20%硫酸溶液中电流密度更小,交流阻抗容抗弧半径更大。XRD测试表明复合镀层的晶粒尺寸相比合金镀层的更小。通过SEM观察两种镀层的微观形貌,发现在电镀液中加入5 g/L纳米TiO2颗粒后获得的镀层形貌明显不同。(2)在直流电镀的基础上,采用单因素变量法研究了电镀脉冲工艺参数对Pd-Ni/TiO2复合镀层电化学性能的影响。包括:电流密度,占空比,频率和电镀温度。结果表明:Pd-Ni/TiO2复合镀层最佳的工艺为:电流密度1 A/dm2,占空比0.8,频率1 Hz和电镀温度 40℃。(3)着重研究了电镀液中不同纳米TiO2含量对所获得镀层的结构与性能的影响。通过XRD测试发现,TiO2的加入能够起到细化晶粒的作用,并且加入量越多,镀层晶粒尺寸越小。通过SEM结果发现,TiO2的加入能够修饰镀层表面的形貌。加入量过大时,在镀层表面观测到了TiO2颗粒团聚现象。EDS与GDOES结果表明,TiO2颗粒的加入还会影响镀层成分的变化。镀液中TiO2颗粒越多,镀层中Pd含量降低,Ni含量反而上升。此外,GDOES测试结果还表明复合镀层中的TiO2颗粒并不是存在于整个镀层的。电化学测试结果表明:5g/LTiO2颗粒镀液中获得的复合镀层耐蚀性最好。然而随着镀液中TiO2颗粒含量继续增加其耐蚀性反而下降。(4)开发了 Pd-Ni-W三元合金电镀工艺,获得了不同W含量的镀层,由于元素W的存在,所得镀层晶粒得到细化。此结果由XRD与阴极极化曲线得到验证。随着电镀液中W含量的增加,所得镀层的Ni含量增加,同时Pd含量随之减少。适量W的添加到Pd-Ni电镀液,从其中得到的Pd-Ni-W三元合金镀层在热硫酸溶液中的耐蚀性会稍有提升。镀层中W含量的增加对于镀层的硬度增加是有利的。Pd-Ni-W合金镀层试样在气液冲击环境下没有机械损伤,但试样的电化学腐蚀速率加快。
[Abstract]:PD-Ni (Pd-Ni) alloys have been widely studied and applied in decoration, electrical contact materials, electrocatalysis, organic synthesis and other fields because of their relatively low cost and excellent comprehensive properties. In this paper, the electroplating process of Pd-Ni alloy film was developed. On the basis of it, Pd-Ni/TiO2 composite coating and Pd-Ni-W ternary alloy coating were prepared on 316L stainless steel surface by electroplating. The corrosion resistance and mechanism of the coating were studied by electrochemical method. The morphology and structure of the coating were characterized by XRD,SEM,EDS,GODES, and the relationship between the morphology and corrosion resistance of the coating was discussed. The specific research is as follows: (1) Pd-Ni alloy coating and Pd-Ni/TiO2 composite coating were prepared by DC plating on 316L stainless steel surface. The electrochemical test results show that the current density of Pd-Ni/TiO2 composite coating is smaller and the AC impedance arc radius is larger in 20% sulfuric acid solution at 60 鈩，
本文编号：2480454
[Abstract]:PD-Ni (Pd-Ni) alloys have been widely studied and applied in decoration, electrical contact materials, electrocatalysis, organic synthesis and other fields because of their relatively low cost and excellent comprehensive properties. In this paper, the electroplating process of Pd-Ni alloy film was developed. On the basis of it, Pd-Ni/TiO2 composite coating and Pd-Ni-W ternary alloy coating were prepared on 316L stainless steel surface by electroplating. The corrosion resistance and mechanism of the coating were studied by electrochemical method. The morphology and structure of the coating were characterized by XRD,SEM,EDS,GODES, and the relationship between the morphology and corrosion resistance of the coating was discussed. The specific research is as follows: (1) Pd-Ni alloy coating and Pd-Ni/TiO2 composite coating were prepared by DC plating on 316L stainless steel surface. The electrochemical test results show that the current density of Pd-Ni/TiO2 composite coating is smaller and the AC impedance arc radius is larger in 20% sulfuric acid solution at 60 鈩，
本文编号：2480454
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