物理化学学报 >> 2003, Vol. 19 >> Issue (11): 996-1000.doi: 10.3866/PKU.WHXB20031102

研究论文 上一篇    下一篇

α-Al2O3与Co-Ni合金电化学共沉积动力学模型

武刚;李宁;王殿龙;周德瑞   

  1. 哈尔滨工业大学应用化学系,哈尔滨 150001
  • 收稿日期:2003-04-03 修回日期:2003-05-27 发布日期:2003-11-15

A Kinetic Model for the Electrolytic Codeposition of α-Al2O3 Particles with Co-Ni Alloy

Wu Gang;Li Ning;Wang Dian-Long;Zhou De-Rui   

  1. Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001
  • Received:2003-04-03 Revised:2003-05-27 Published:2003-11-15

摘要: 在经典复合电沉积机理基础上,考虑到粒子与电极表面之间的多种作用力,以吸附强度来表征粒子与电极表面的作用力大小,根据粒子在电极表面的临界吸附强度,把粒子的吸附分为有效吸附和非有效吸附.当吸附强度大于临界吸附强度时,粒子能被有效吸附嵌入到沉积层中,粒子被有效吸附的概率和平均吸附强度有关.建立了相应的复合电沉积动力学模型.该模型在α-Al2O3与Co-Ni合金的复合共沉积体系中,在电流密度为1~20 A•dm2范围内得到了验证.通过数学模型和实验结果研究了电流密度对粒子沉积量φc、吸脱附常数K、有效吸附概率P和平均吸附强度的影响规律.

关键词: 动力学模型, 电化学共沉积机理, 吸附强度, Co-Ni合金, α-Al2O3

Abstract: A new kinetic model for the electrolytic codeposition of α-Al2O3 particles with Co-Ni alloys on a rotation disk electrode is presented, which is based on the balance of force acting on a particle near the electrode surface. Adsorption strength of particles on the electrode was used to describe the force intensity of the interaction between the particles and the electrode. The critical adsorption strength was used to classify the adsorption into effective adsorption and non-effective adsorption. Only when the adsorption strength of a particle is above the critical value, the adsorption becomes effective and may be incorporated into the deposit. The probability of the particles being effective adsorption dependents on the average adsorption strength, which is effected by the force acting on the particle. A kinetic mathematical model relating the content of embedded particles to suspension concentration was deduced. This relationship was verified experimentally by the codeposition systems of α-Al2O3/Co-Ni at the current density ranged from 1 to 20 A•dm-2. The variation of the content of particles in deposits with current density is an overall balance of two opposing effects, which leads to a maximum on the particle content against current density curves. Some model parameters were determined also by comparing theory and experimental data.

Key words: Kinetic model, Electrochemical codepositon mechanism, Adsorption strength, Co-Ni alloys, α-Al2O3