氟钛酸钾添加对铝镁复合板微弧氧化涂层结构及耐蚀性的影响  

Effect of K_(2)TiF_(6) Concentration on Microstructure and Corrosion Resistance of Al-Mg Composite Plate Based Micro-arc Oxidation Coatings

作　　者：杨瑞霞 谢小梦 杨尔慧 凌奎 李伟洲 YANG Ruixia;XIE Xiaomeng;YANG Erhui;LING Kui;LI Weizhou(School of Resources,Environment and Materials,Guangxi University,Nanning 530004,China;Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials,Nanning 530004,China;School of Materials Science and Engineering,Xiamen University of Technology,Xiamen 361024,China)

机构地区：[1]广西大学资源环境与材料学院,南宁530004 [2]广西有色金属及特色材料加工重点实验室,南宁530004 [3]厦门理工学院材料科学与工程学院,厦门361024

出　　处：《中国表面工程》2023年第2期166-179,共14页China Surface Engineering

基　　金：国家自然科学基金(51371059);广西科技重大专项(AA18118030,AA17204100)资助项目。

摘　　要：为研究氟钛酸钾(K_(2)TiF_(6))添加对Al-Mg复合板微弧氧化涂层结构和耐腐蚀性能的影响,在硅酸盐-氢氧化钠电解液体系中加入不同浓度的氟钛酸钾(0、1、2和3 g·L^(-1)),利用微弧氧化技术(MAO)在Al-Mg复合板表面制备陶瓷氧化物涂层。通过SEM、XRD、EDS和电化学工作站等对制备陶瓷氧化物涂层显微组织、相组成、形貌及耐蚀性能进行表征。添加K_(2)TiF_(6)后,Al-Mg复合板Al侧的涂层厚度、表面孔隙率和表面粗糙度随K_(2)TiF_(6)浓度的增加呈下降的趋势(24.2~18.4μm、6.8%~5.3%、3.55~2.23),Mg侧涂层呈上升趋势(21.0~26.6μm、3.6%~5.3%,3.35~4.33),此外涂层中的Ti和F元素含量增加,各样品的耐蚀性均有所提高。添加K_(2)TiF_(6)为2 g·L^(-1)时,两侧涂层的耐蚀性最好,其中R_(t)均比未添加的样品增加2个数量级,i_(corr)均下降1个数量级。氟钛酸钾的加入可改变Al-Mg复合板微弧氧化涂层结构,提高Al-Mg复合板耐腐蚀性能。Micro-arc oxidation(MAO)can form an in-situ ceramic oxide film on the valve metal surfaces of Al and Mg,and it is a surface treatment method for Al-Mg composite plates.In the MAO process,different additives or different concentrations of the same additive added to the electrolyte can affect the MAO behavior,film microstructure,and corrosion resistance of the coatings.To explore the influence of K_(2)TiF_(6)concentrations on the microstructure and corrosion resistance of Al-Mg composite plate-coating-based MAO coatings,in this paper,MAO was applied to deposit ceramic oxide coatings on Al-Mg composite plates with different concentrations K_(2)TiF_(6)addition(0,1,2,and 3 g·L^(-1))in the Na Si O_(3)-Na OH electrolyte.The MAO behavior,coating structure,and corrosion resistance of the Al-Mg composite plate coating with 40 min of oxidation were studied.The micromorphology and phase structure composition of the Al-Mg composite plate ceramic oxide coatings were analyzed using SEM,XRD,XPS,EDS,and 3D surface profilers.The corrosion resistance of the coating was studied using an electrochemical workstation and a salt-mist corrosion tester.The addition of K_(2)TiF_(6)increased the breakdown voltage and discharge intensity of the Al-Mg composite plate,thereby promoting the growth of coatings on both sides of the composite plate and increasing the number of defects.The coating in the contact region of the welding surface was continuous and tightly bonded,indicating that the composite plate was protected by the coating.The coatings on the Al side were mainly composed ofγ-Al_(2)O_(3)and mullite phases,while the Mg side coatings were all composed of Mg O and Mg_(2)SO_(4)phases.After the addition of K_(2)TiF_6,the Ti and F contents in the ceramic oxide coating increased,and the corrosion resistance was enhanced in all samples.These characteristics of coating thickness,surface porosity,and roughness on the Al side of Al-Mg composite plate showed a decreasing trend with the increase of K_(2)TiF_(6)concentration,namely,its thickness

关 键 词：氟钛酸钾 微弧氧化 涂层结构 耐腐蚀性 

分 类 号：TG178[金属学及工艺—金属表面处理]