铜锌合金表面CeO_(2)颗粒掺杂微弧氧化复合膜层的制备及性能分析  

Fabrication and Performance of Micro-Arc Oxidized Composite Film Doped with CeO_(2)Particles

作　　者：王帅柯 孟建兵[1] 关庆义 董小娟[1] 于浩洋 李红梅 李丽[1] WANG Shuai-ke;MENG Jian-bing;GUAN Qing-yi;DONG Xiao-juan;YU Hao-yang;LI Hong-mei;LI Li(School of Mechanical Engineering,Shandong University of Technology,Shandong Zibo 255000,China)

机构地区：[1]山东理工大学机械工程学院,山东淄博255000

出　　处：《表面技术》2023年第1期152-161,共10页Surface Technology

基　　金：国家自然科学基金(51875328);山东省自然科学基金(ZR2021ME159)。

摘　　要：目的提高铜锌合金的耐蚀性,对黄铜表面进行颗粒掺杂微弧氧化(MAO),研究纳米颗粒CeO_(2)对复合膜层性能的影响。方法以Na_(2)SiO_(3)·9H_(2)O、NaOH的混合溶液作为电解液,对铜锌合金进行微弧氧化,以膜层厚度和自腐蚀电流密度为评价指标,对氧化时间、正向电压、反向电压、占空比进行正交试验和极差分析,得到最佳微弧氧化电参数。将CeO_(2)添加到混合电解液中,以制备颗粒掺杂微弧氧化复合膜层。通过SEM、EDS、XRD、动电位极化曲线和电化学交流阻抗测试等手段,研究CeO_(2)纳米颗粒对膜层表面、横截面的微观形貌和成分组成及膜层表面的物相结构和耐蚀性能的影响。结果以自腐蚀电流密度为主要评价指标,兼顾膜层厚度,通过正交试验和极差分析,得到了铜锌合金微弧氧化最佳电参数组合,氧化时间为80 min,占空比为20%,正向电压为550 V,反向电压为5 V。未添加CeO_(2)的黄铜试件,微弧氧化膜层表面存在粗糙多孔的结构;掺杂纳米颗粒CeO_(2)后,复合膜层表面变得更为平整,表面粗糙度Ra值从3.883μm降至3.331μm,孔隙率也由颗粒掺杂前的35.11%降至32.98%。随着CeO_(2)颗粒的掺杂,膜层表面的C、O、Si、Ce元素增加,Cu、Zn元素下降,膜层表面的物相主要由CuO、ZnO、CeO_(2)和SiO_(2)组成。纳米颗粒CeO_(2)掺杂前后,膜层均与黄铜基体结合紧密,无明显裂缝。沿着膜层表面向基体方向,Cu和Zn元素含量短暂上升后保持平稳,而O和Si元素含量变化情况为先增加、后减小至消失。颗粒掺杂前,MAO膜层的自腐蚀电流密度J_(corr)为8.095×10^(-4)A/cm^(2),掺杂纳米颗粒CeO_(2)后,J_(corr)为7.402×10^(-5)A/cm^(2)。两者与黄铜基体的J_(corr)(1.236×10^(-2)A/cm^(2))相比,分别下降了2、3个数量级。结论对铜锌合金进行微弧氧化可以在合金表面制得多孔且有良好耐蚀性的陶瓷膜层。纳米颗粒CeO_(2)的掺杂,能够有效改善铜锌合金微�For copper and copper alloy,because copper is a non-valve metal,such as steel,zinc,nickel,niobium and other metals,it is generally considered that it is difficult to establish a stable plasma discharge channel in the initial stage of plasma electrolytic oxidation,and it is difficult to form a dense insulating film.The work aims to carry out particle doping micro-arc oxidation(MAO)on the surface of brass and study the effects of nanoparticle CeO_(2)on the properties of composite films to improve the corrosion resistance of copper-zinc alloy.The mixed solution of Na_(2)SiO_(3)·9H_(2)O and Na OH was used as the electrolyte to conduct micro-arc oxidation on Cu-Zn alloy.The film thickness and selfcorrosion current density were taken as evaluation indexes.The oxidation time,forward voltage,reverse voltage and duty cycle were analyzed by orthogonal test and range analysis,and the optimal micro-arc oxidation electrical parameters were obtained.CeO_(2)was added to the mixed electrolyte to prepare the micro-arc oxidation composite film.By means of SEM,EDS,XRD,potentiodynamic polarization curve and electrochemical AC impedance test,the effects of CeO_(2)nanoparticles on the microscopic morphology and composition of the film surface and cross-section,the physical phase structure and the corrosion resistance of the film surface were studied.With the self-corrosion current density as the main evaluation index and after considering the film thickness,the optimum combination of electrical parameters for micro-arc oxidation of Cu-Zn alloy was obtained by orthogonal test and range analysis,that was:oxidation time 80 min,duty cycle 20%,forward voltage 550 V,reverse voltage 5 V.The surface of the micro-arc oxidation film of brass specimens without CeO_(2)was rough and porous.The surface of the composite film became more flat,and the surface roughness Ra value decreased from 3.883μm to 3.331μm after CeO_(2)doping,the porosity of the doped particles also decreased from 35.11%to32.98%.With the doping of CeO_(2)particles,elements C,O

关 键 词：铜锌合金 微弧氧化 二氧化铈 颗粒掺杂 耐蚀性能 膜层厚度 

分 类 号：TG174.4[金属学及工艺—金属表面处理]