添加剂铬酸钾对TC4钛合金微弧氧化膜层性能的影响  

Influence of potassium chromate as additive on performance of micro-arc oxidation coating prepared on TC4 titanium alloy

作　　者：林修洲[1,2] 唐唯[1,2] 杜勇[1,2] 崔学军[1,2] 

机构地区：[1]四川理工学院材料腐蚀与防护四川省重点实验室,四川自贡643000 [2]四川理工学院材料与化学工程学院,四川自贡643000

出　　处：《电镀与涂饰》2013年第7期35-37,共3页Electroplating & Finishing

基　　金：材料腐蚀与防护四川省重点实验室开放基金重点项目(2011CL01);自贡市科技局重点项目(2011G027);四川理工学院培育项目(2011PY03);四川理工学院人才引进项目(2012RC06)

摘　　要：以TC4钛合金为基体,在硅酸钠电解液中进行微弧氧化(MAO)。电解液的主要成分为Na2SiO3、Na3PO4和NaOH,工艺条件为:电压450V,频率500Hz,占空比30%,时间5min。通过向电解液中添加0.5g/LK2CrO4对微弧氧化膜层进行着色。采用涡流测厚仪、维氏硬度计、扫描电镜、X射线荧光光谱分析仪以及中性盐雾试验等,研究了K2CrO4添加剂对膜层厚度、显微硬度和形貌等性能的影响。结果表明,所得微弧氧化膜层为典型的不规则多孔氧化物陶瓷膜层,显微硬度和耐蚀性明显优于基材。在电解液中加入K2CrO4后,MAO膜层由灰色转变为深黄色;K2CrO4使膜层粗糙度和孔径增大,与基体结合处的缺陷减少,结合力增强;膜层的脆性和内应力降低,耐蚀性增强。Micro-arc oxidation （MAO） was carried out insodium silicate electrolyte using TC4 titanium alloy as thesubstrate. The main components of electrolyte are Na2SiO3,Na3P04, and NaOH. The process conditions are as follows：voltage 450 V, frequency 500 Hz, duty cycle 30%,and time5 min. 0.5 g/L K2CrO4 was added to electrolyte for thecoloring of MAO coating. The effect of K2CrO4 as additiveon the performances of MAO coating such as thickness,microhardness, and morphology was studied by eddy currentthickness meter,Vickers hardness tester, scanning electronmicroscopy, X-ray fluorescence spectroscopic analysis, andneutral salt spray testing. The results show that the obtained MAO coating is typically irregular-porous oxide ceramiccoating, and has higher microhardness and better corrosion resistance than substrate. The addition of K2CrO4 to theelectrolyte changes the color of MAO coating from gray todark yellow, increases the roughness and pore size of MAO coating, reduces the number of defects between MAO coating and substrate, strengthens the adhesion of MAO coating to substrate, and decreases the brittleness and internalstress, improving corrosion resistance of MAO coating.

关 键 词：钛合金 微弧氧化 铬酸钾 着色 性能 

分 类 号：TQ153.6[化学工程—电化学工业]