通过极化曲线研究了3种不同溶液(阴极液、阳极液和完整镀液)的电化学行为,测定了主盐、还原剂浓度以及镀液pH和体系温度对化学镀镍沉积速率的影响. 与直接在镁合金上化学镀镍并使用重量分析法得到的沉积速率相比较发现,完整镀液体系的极化曲线才能真实地反映化学镀镍的沉积过程,其过程不能简单视为由彼此完全独立毫无关联的阴阳极半反应构成. 根据Butler-Volmer公式,本化学镀液体系的化学镀镍过程属混合控制,其表观反应活化能为42.89 kJ·mol-1.
Electrochemical behaviors of electroless nickel (EN) plating in three systems, namely, cathodic, anodic and complete bath solutions were investigated by polarization methods. The curves in the complete baths were not entirely consistent with those expected from a combination of the anodic and cathodic polarization curves, which implies that the anodic and cathodic reactions of the EN plating are interdependent. The effects of concentration of nickel ions, hypophosphite and pH on the polarization parameter and deposition rate in a complete bath were also discussed and compared by performing electrochemical and gravimetrical measurements. Based on these variations in the deposition potential and current density, a kinetic expression employing the Butler-Volmer equation is suggested and verified with the experimental findings. It was confirmed that the electroless nickel deposition processes in the present system was under a mixed control. The apparent activation energy determined by electrochemical methods was about 42.89 kJ·mol-1.
[1]Alkire R C, Kolb D M. Advances in electrochemical science and engineering (vol. 7)[M]. Weinheim: Wiley-VCH Verlag GmbH, 2001: Chapter 5.
[2]Paunovic M, Vitkavage D. Determination of electroless copper deposition rate from polarization data in the vicinity of the mixed potential[J]. Journal of the Electrochemical Society, 1979, 126(12): 2282-2284.
[3]Ohno I. Electroless copper plating from an iminodiacetate bath[J]. Surface Technology, 1976, 4(6): 515-520.
[4]Hung A, Ohno I. Electrochemical study of hypophosphite-reduced electroless copper deposition[J]. Journal of the Electrochemical Society, 1990, 137(3): 918-921.
[5]Inberg A, Bogush V, Croitoru N, et al. Electrochemical study of the mechanism of Ag(W) electroless deposition[J]. Journal of the Electrochemical Society, 2007, 154(1): D1-D4.
[6]Petrov N, Sverdlov Y, Shacham-Diamand Y. Electrochemical study of the electroless deposition of Co(P) and Co(W, P) alloys[J]. Journal of the Electrochemical Society, 2002, 149(4): C187-C194.
[7]Kato M, Niikura K, Hoshino S, et al. Electrochemical behavior of electroless gold plating with ascorbic acid as a reducing agent[J]. The Surface Finishing Society of Japan, 1991, 42(7): 729-735.
[8]Mishra K G, Paramguru R K. Kinetics and mechanism of electroless copper deposition at moderate-to-high copper ion and low-to-moderate formaldehyde concentrations[J]. Metallurgical and Materials Transactions B, 1999, 30(2): 223-229.
[9]Mishra K G, Paramguru R K. Kinetics and mechanism of electroless deposition of copper[J]. Journal of the Electrochemical Society, 1996, 143(2): 510-516.
[10]Li J, Kohl P A. The acceleration of non formaldehyde electroless copper plating[J]. Journal of the Electrochemical Society, 2002, 149(12): C631-C636.
[11]Bindra P, Roldan J. Mechanisms of electroless metal plating. III. Mixed potential theory and the interdependence of partial reactions[J]. Journal of Applied Electrochemistry, 1987, 17(6): 1254-1266.
[12]Abrantes L M, Correia J P. On the mechanism of electroless Ni-P plating[J]. Journal of the Electrochemical Society, 1994, 141(9): 2356-2360.
[13]Haruyama S, Yoshizawa A, Ohno I. Estimation of the rate of electroless cobalt plating by electrochemical method[J]. Journal of the Metal Finishing Society of Japan, 1979, 30(6): 289-293.
[14]Barker B D, Taberner D. Electrochemical aspects of the electroless deposition of cobalt[J]. Surface Technology, 1981, 12(1):103-104.
[15]Ohno I, Haruyama S. Measurement of the instantaneous rate of electroless plating by an electrochemical method[J]. Surface Technology, 1981, 13(1): 1-15.
[16]Conway B E, White R E. Modern aspects of electrochemistry (vol. 35)[M]. New York: Kluwer Academic Publishers, 2002: Chapter 2.
[17]Yang F Z(杨防祖), Yang B(杨斌), Lu B B(陆彬彬), et al. Electrochemical study on electroless copper plating using sodium hypophosphite as reductant[J]. Acta Physico-Chimica Sinica(物理化学学报), 2006, 22(11): 1317-1320.
[18]Abyaneh M Y, Sterritt A, Mason T J. Effects of ultrasonic irradiation on the kinetics of formation, structure, and hardness of electroless nickel deposits[J]. Journal of the Electrochemical Society, 2007, 154(9): D467-D472.
[19]Malecki A, Micek-Ilnicka A. Electroless nickel plating from acid bath[J]. Surface and Coatings Technology, 2000, 123(1): 72-77.
[20]Xie Z H, Yu G, Li T J, et al. Dynamic behavior of electroless nickel plating reaction on magnesium alloys[J]. Journal of Coatings Technology and Research, 2012, 9(1): 107-114.
[21]Huang G F, Huang W Q, Wang L L, et al. Electrochemical study of electroless deposition of Fe-P alloys[J]. Electrochimica Acta, 2006, 51(21): 4471-4476.
[22]Gui L F(桂立丰). Handbook of materials testing for mechanical engineering: Corrosion and friction[M]. Liaoning: Liaoning Science and Technology Press(辽宁科学技术出版社), 2002, Chapter 1.
[23]Gorker L, Dimitrov V. Modified tafel equation for electroless metal deposition[J]. Progress in Reaction Kinetics and Mechanism, 2009, 34(2): 127-140.
[24]Gamburg Y D, Zangari G. Theory and practice of metal electrodeposition[M]. New York: Springer, 2011: Chapter 3.
[25]Kanani N. Electroplating: Basic principles, processes and practice[M]. Oxford UK: Elsevier, 2004: Chapter 4.