脉冲频率对镁锂合金黑色微弧氧化膜层耐磨与抗腐蚀性能的影响  

Effect of Pulse Frequency on the Wear and Corrosion Resistance of Black Micro Arc Oxidation Coatings on Magnesium Lithium Alloy in Marine Environment

作　　者：饶模松 杨巍[1] 魏明珠 程赵辉 金耀华[1] RAO Mosong;YANG Wei;WEI Mingzhu;CHENG Zhaohui;JIN Yaohua(School of Materials and Chemical Engineering,Xi'an Technological University,Xi'an 710021,China)

机构地区：[1]西安工业大学材料与化工学院,西安710021

出　　处：《表面技术》2024年第18期116-125,共10页Surface Technology

基　　金：国家自然科学基金项目(52071252);陕西省产业重点研发计划项目(2022GY-407,2021ZDLSF03-11)。

摘　　要：目的探究脉冲频率对镁锂合金黑色微弧氧化膜层的色度及其在海洋环境的耐磨性能和抗腐蚀性能的影响。方法复合添加Cu_(2)P_(2)O_(7)和CoSO42种着色盐,并调控脉冲频率在镁锂合金表面制备了黑色微弧氧化膜层。结果由于脉冲频率的增加,Co元素在膜层中含量占比逐步增加、而Cu元素含量占比逐步减少,膜层由红棕色转变为黑色,黑度值最小可达24.95;频率为1000Hz时,摩擦因数仅为0.13,磨痕宽度为206.52μm,耐磨性能显著提升,且腐蚀增重最少,仅为0.5 mg/cm^(2)。阻抗提升了1个数量级。结论调控脉冲频率可影响微弧氧化过程中的弧光放电现象,增大脉冲频率可增大膜层黑度;其结构更加致密,从而提升了膜层耐磨性能及抗腐蚀性能。Magnesium lithium alloy is a metal structural material with excellent comprehensive performance,which has broad application prospects in fields such as shipborne aircraft.However,the poor wear and corrosion resistance of magnesium lithium alloy in marine environment greatly limits its application and promotion.In addition,the engineering application of magnesium lithium alloy also needs to meet the requirements of decoration,absorption or shielding of stray light.A black micro arc oxidation coating was prepared by adding two colored salts,copper pyrophosphate(Cu_(2)P_(2)O_(7))and cobalt sulfate(CoSO4)to the electrolyte.The resulting coating exhibited numerous defects such as microcracks.The microstructure and phase composition of the micro arc oxidation(MAO)coating were improved by adjusting the pulse frequency to enhance its wear and corrosion resistance in marine environment.In the experiment,with LA103Z magnesium lithium alloy as the substrate and 5 g/L Na_(2)SiO_(3),8 g/L KF,12 g/L NaOH,15 g/L KNaC4H4O6·4H_(2)O,3 g/L sodium citrate,5 g/L copper pyrophosphate,and 3 g/L CoSO4·7H_(2)O as the electrolyte,a black MAO coating was prepared on the surface of the magnesium lithium alloy by adjusting the frequency(200,400,600,800,1000 Hz).The electrical parameters used were as follows:voltage of 300 V,duty cycle of 3%and oxidation time of 10 min.The blackness value of MAO coating was measured with a CR9000 spectrophotometer.TESCAN VEGA 3 scanning electron microscope and its accompanying energy dispersive spectrometer were used to characterize the wear morphology of the coating,as well as the microstructure and element content before and after corrosion.Bruker D8 XRD was used to characterize the phase composition of coatings,with scanning angles and step sizes of 20°-90°and 0.02(°)/s,respectively.AXIS Ultra DLD XPS was used to characterize the surface composition of coatings.The HT-1000 friction and wear testing machine produced by Lanzhou Zhong Ke Kaihua was used to characterize the wear resistance of coatings in

关 键 词：镁锂合金 微弧氧化 黑色 海洋环境 耐磨性 耐蚀性 

分 类 号：TG174[金属学及工艺—金属表面处理]