钒酸钠型无铬达克罗涂层的制备与性能  

Preparation and properties of chromium-free Dacromet coating based on sodium vanadate

作　　者：李敏[1] 李庆鹏[1,2] 阎磊 刘利冉 杨宏强 李梦雪 管勇 王娜[1,2] LI Min;LI Qingpeng;YAN Lei;LIU Liran;YANG Hongqiang;LI Mengxue;GUAN Yong;WANG Na(Liaoning Provincial Key Laboratory of Synthesis and Preparation of Special Functional Materials,Shenyang University of Chemical Technology,Shenyang 110142,China;Shenyang Advanced Coating Materials Industrial Technology Research Institute,Shenyang 110330,China;Shenyang Jinbei Yanfeng Automotive Interior System Co.,Ltd.,Shenyang 110179,China;Shenyang Hangda Technology Co.,Ltd.,Shenyang 110034,China;Department of Material Service Behavior,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]沈阳化工大学辽宁省特种功能材料合成与制备重点实验室,辽宁沈阳110142 [2]沈阳先进涂层材料产业技术研究院,辽宁沈阳110330 [3]沈阳金杯延锋汽车内饰系统有限公司,辽宁沈阳110179 [4]沈阳市航达科技有限责任公司,辽宁沈阳110034 [5]中国科学院金属研究所材料使役行为研究部,辽宁沈阳110016

出　　处：《电镀与涂饰》2022年第24期1735-1744,共10页Electroplating & Finishing

基　　金：2021年辽宁省“揭榜挂帅”科技攻关项目(2021JH1/10400091);辽宁省教育厅2021年科研资助项目(LJK Z0470);辽宁省“兴辽英才计划”(XLYC2005002);沈阳市科学技术计划-重大关键核心技术攻关专项(20-202-1-15)。

摘　　要：采用钒酸钠作为钝化剂,硅烷偶联剂(A-187)水解液作为成膜物,锌铝粉作为牺牲阳极的主要组分,制备了一种高性能的环保水性无铬达克罗涂层,研究了钒酸钠的存在对无铬达克罗涂层腐蚀行为的影响。采用傅里叶变换红外光谱仪(FT-IR)对硅烷偶联剂水解液和锌铝粉进行表征,探讨了钒酸钠添加量对硅烷偶联剂水解液成分的影响。采用扫描电子显微镜(SEM)、X射线衍射(XRD)、动电位极化曲线测量、电化学阻抗谱(EIS)等手段,研究了锌铝粉在涂料中的分散状态及钒酸钠添加量不同的无铬达克罗涂层的耐蚀性。结果表明:钒酸钠的添加不仅对硅烷水解液的稳定性无不良影响,还在一定程度上促进了硅烷的水解。钒酸钠添加量为0.4%~1.0%时,涂料具有优异的贮存稳定性,且涂层表面光滑平整,无明显缺陷,中性盐雾试验720 h后无红锈产生。当钒酸钠添加量为0.7%时,无铬达克罗涂层的腐蚀电流密度最低,阻抗模值较大,其防腐性能最佳。将适量钒酸钠作为钝化剂加入到无铬达克罗涂层中能有效钝化锌铝粉填料,提高涂层的耐蚀性。A kind of high-performance and environmentally friendly water-based chromium-free Dacromet coating was prepared with sodium vanadate as passivator,the hydrolysate of silane coupling agent A-187 as binder,and Zn-Al powder as sacrificial anode.The effect of the existence of sodium vanadate on the corrosion behavior of chromium-free Dacromet coating was studied.The silane hydrolysate and the Zn-Al powder were characterized by Fourier-transform infrared spectroscopy(FT-IR).The dosage of sodium vanadate on the composition of the silane hydrolysate was discussed.The dispersion of Zn-Al powder in the coating material and the corrosion resistance of chromium-free Dacromet coatings with different contents of sodium vanadate were examined by scanning electron microscopy(SEM),X-ray diffraction(XRD),potentiodynamic polarization measurement,and electrochemical impedance spectroscopy(EIS).The results showed that the addition of sodium vanadate not only has no adverse effect on the stability of the silane hydrolysate,but also promotes the hydrolysis of silane to a certain extent.The coating material containing 0.4%to 1.0%of sodium vanadate had good storage stability,and the coating prepared therewith had a smooth surface without any obvious defects.There was no red rust for the chromium-free Dacromet coatings after 720 hours of neutral salt spray test.The coating with 0.7%of sodium vanadate had the lowest corrosion current density and the largest impedance magnitude,showing the best corrosion resistance.The appropriate amount of sodium vanadate as passivator can passivate the Zn-Al powder as filler effectively and improve the corrosion resistance of coating.

关 键 词：无铬达克罗涂层 锌铝涂层 钒酸钠 钝化剂 硅烷偶联剂 耐蚀性 电化学测量 

分 类 号：TQ630[化学工程—精细化工]