摘要
采用微弧氧化技术在AZ91镁合金表面制备陶瓷涂层,然后在该涂层表面通过磁控溅射镀铜技术制备复合膜层。研究了微弧氧化陶瓷层和复合膜层的表面物相组成、表面粗糙度、表面及截面形貌、表面润湿性及电化学性能。结果表明:AZ91镁合金经微弧氧化处理后由于微弧氧化陶瓷层呈微纳粗糙多孔结构,表现为亲水特性,其物相由MgO、Mg及Mg_2SiO_4组成;而微弧氧化陶瓷层经磁控溅射镀铜处理后表面获得较为致密的具有疏水特性的铜层,表面粗糙度降低;四探针测试结果说明复合膜层的方阻为16.2 m?·^(-1),导电性良好;动电位极化曲线测试结果说明复合膜层与基体镁合金相比,其腐蚀电流密度降低10%,腐蚀电位提高了约0.36 V,腐蚀极化电阻提高约80倍;与微弧氧化陶瓷层相比,复合膜层的腐蚀电位提高了约0.24 V,但其腐蚀电流密度和腐蚀极化电阻有所下降。研究结果表明,微弧氧化与磁控溅射镀铜相结合的复合处理技术可在不降低镁合金陶瓷层耐蚀性的基础上显著提高其表面的导电性能。
Porous ceramic coatings were prepared on AZ91 magnesium alloy by micro-arc oxidation （MAO）, and then duplex coatings were prepared by magnetic sputtering copper. The surface phase composition, surface roughness, surface and cross-sectional morphology, surface wettability, and electrochemical characteristics of MAO and duplex coatings were studied. The results indicate that the surface of AZ91 magnesium alloy treated by MAO is hydrophilic due to its micro-nano coarse porous structure, and its phases include MgO, Mg and Mg2SiO4. However, the surface of MAO coating turns into relatively compact copper with hydrophobic property after magnetic sputtering copper, and the surface roughness decreases. Four-point probe measurement indicates that the duplex coating exhibits well electrical conductivity, and the sheet resistance is 16.2 mΩ·D-1. Meanwhile, potentiodynamic polarization curves reveal that the corrosion current density of the duplex coating decreases by 10%, and the corrosion potential increases by about 0.36 V, while the polarization resistance increases by around 80 times compared with bare magnesium alloy. Compared with the MAO coating, the corrosion potential of the duplex coating increases by about 0.24 V, suggesting that the corrosion trend decreases. Nevertheless, the corrosion current density and polarization resistance of the duplex coating all decrease to some extent. These survey results indicate that the duplex treatment of MAO and magnetic sputtering copper on surface of the magnesium alloy improves its electrical conductivity greatly without losing its corrosion resistance.
作者
王志虎
白力静
王爱玲
张国君
Wang Zhihu;Bai Lijing;Wang Ailing;Zhang Guojun(Xi＇an University of Technology,Xi＇an 710048,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2018年第8期2561-2566,共6页
Rare Metal Materials and Engineering
基金
陕西省自然科学基础研究计划(重点项目)(2016JZ018)
关键词
镁合金
微弧氧化
磁控溅射
复合膜层
耐蚀性
magnesium alloy
micro-arc oxidation
magnetic sputtering
duplex coating
corrosion resistance
