溶射鋁／硬質陽極複合皮膜之防蝕性與耐磨性

An Investigation of Thermal Sprayed Aluminum/Hard Anodic Composite Coating on Wear and Corrosion Resistant Performance

以熔射方式噴覆陽極材料為常見的鋼鐵材防蝕技術，高孔隙率是熔射皮膜與生俱來的缺點，同時也是造成皮膜防蝕功能失效的主因。本研究旨在探討熔射鋁／硬質陽極複合皮膜之耐蝕性與耐磨性，於低碳鋼試片上分別以電弧熔射與火焰熔射法製備熔射鋁層，接著以硫酸法進行硬質陽極處理，獲得一緻密的硬質陽極氧化膜。完成之試片分別進行微硬度試驗、耐磨耗實驗、鹽霧試驗、電化學AC阻抗量測及表面、截面之SEM觀察，以評估此一複合表處皮膜之防蝕與耐磨耗效果。研究結果顯示，經研磨後之熔射鋁層可直接進行硬質陽極處理，陽極處理後之複合皮膜，對防蝕性與與耐磨性均有顯著之提昇效果。

Anodic materials coated on the steel by thermal spray is a familiar anti-corrosion method. But high porosity is the inherent defect for thermal spray coatings. It is also the main reason that the anti-corrosion performance breaks down. This paper focused on the investigation of the corrosion protection and abrasion resistance properties of thermal spray aluminum /hard anodic composite coatings. In this study the low carbon steel coated with pure aluminum by arc thermal spray first, and then the specimens recoated by hard anodizing process with sulfuric acid solution. Finally more dense and hard oxidative coatings could be obtained. The anti-corrosion and wear-resistance effects of the composite coated specimens were examined with micro-hardness test, abrasion resistance test, salt fog test, electrochemical AC impedance evaluation and scanning electronic microscope. The results showed that aluminum coating prepared by arc thermal spray could be directly post-treated with anodizing. The hard anodic composite coatings possessed good anti-corrosion and abrasion resistance properties, and their corrosion protection effect increased with the increase of anodic post-treatment time.