The porous anodic aluminum oxide (AAO) film on a pure aluminum substrate was pre pared by a two-step anodization in a 0.3M oxalic acid solution and pore-enlargem ent treatment in the phosphoric acid aqueous solution a...The porous anodic aluminum oxide (AAO) film on a pure aluminum substrate was pre pared by a two-step anodization in a 0.3M oxalic acid solution and pore-enlargem ent treatment in the phosphoric acid aqueous solution at 50℃. The diameter of h ighly ordered pore on the AAO film was about 90nm, and the thickness of the AAO film was 3μm. The mineral oil was infiltrated in the ordered nanometer sized po res of AAO film on an aluminum substrate due to the capillarity effect. The fric tion coefficient was measured using a ball-on-disk tribotester. The tests were c onducted at loads range from 490 to 2450mN and at sliding velocities between 0.1 and 0.5m·s-1. Oil infiltration in porous AAO film modified friction and consid erably improved the wear resistance. As compared to the porous AAO film, the oil -infiltrated specimen had low friction coefficient. With increasing the applied load and sliding velocity, the friction coefficient of the oil-infiltrated film decreased. It indicates that the oil-infiltrated AAO film produced a new way to modify the friction and wear of aluminum alloy.展开更多
A Zn‐based coating with durable hydrophobicity and good corrosion resistance was formed on a mild steel substrate,which involves electroplating Zn from a non‐aqueous electrolyte,followed by passivation in an oleic a...A Zn‐based coating with durable hydrophobicity and good corrosion resistance was formed on a mild steel substrate,which involves electroplating Zn from a non‐aqueous electrolyte,followed by passivation in an oleic acid(OA)solution.The electrodeposited Zn coatings were porous,which facilitated the formation of a chemical conversion layer of Zn oleate(ZO)during OA passivation.The Zn coating after passivation had a twolayer structure,which included an outer layer of ZO with a thickness of~26μm and an inner layer of Zn with a thickness of~6μm.The outer layer ZO is a type of metal soap with a smooth surface and durable hydrophobicity,such that water droplets can easily slip off its surface.Corrosion testing and electrochemical measurements in 3.5 wt.%NaCl aqueous solution indicate that the Zn coating after OA passivation exhibits outstanding anti‐corrosion properties compared with those exhibited by pure Zn coating.The corrosion products and mechanism of the two‐layer coating were explored.This study shows that smooth metal oleate coatings can provide hydrophobicity and corrosion resistance simultaneously to mild steel substrates.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.50271067)Zhejiang Provincial Natural Science Foundation of China(No.ZC0203).
文摘The porous anodic aluminum oxide (AAO) film on a pure aluminum substrate was pre pared by a two-step anodization in a 0.3M oxalic acid solution and pore-enlargem ent treatment in the phosphoric acid aqueous solution at 50℃. The diameter of h ighly ordered pore on the AAO film was about 90nm, and the thickness of the AAO film was 3μm. The mineral oil was infiltrated in the ordered nanometer sized po res of AAO film on an aluminum substrate due to the capillarity effect. The fric tion coefficient was measured using a ball-on-disk tribotester. The tests were c onducted at loads range from 490 to 2450mN and at sliding velocities between 0.1 and 0.5m·s-1. Oil infiltration in porous AAO film modified friction and consid erably improved the wear resistance. As compared to the porous AAO film, the oil -infiltrated specimen had low friction coefficient. With increasing the applied load and sliding velocity, the friction coefficient of the oil-infiltrated film decreased. It indicates that the oil-infiltrated AAO film produced a new way to modify the friction and wear of aluminum alloy.
基金Zhejiang University K.P.Chao's High Technology Development Foundation。
文摘A Zn‐based coating with durable hydrophobicity and good corrosion resistance was formed on a mild steel substrate,which involves electroplating Zn from a non‐aqueous electrolyte,followed by passivation in an oleic acid(OA)solution.The electrodeposited Zn coatings were porous,which facilitated the formation of a chemical conversion layer of Zn oleate(ZO)during OA passivation.The Zn coating after passivation had a twolayer structure,which included an outer layer of ZO with a thickness of~26μm and an inner layer of Zn with a thickness of~6μm.The outer layer ZO is a type of metal soap with a smooth surface and durable hydrophobicity,such that water droplets can easily slip off its surface.Corrosion testing and electrochemical measurements in 3.5 wt.%NaCl aqueous solution indicate that the Zn coating after OA passivation exhibits outstanding anti‐corrosion properties compared with those exhibited by pure Zn coating.The corrosion products and mechanism of the two‐layer coating were explored.This study shows that smooth metal oleate coatings can provide hydrophobicity and corrosion resistance simultaneously to mild steel substrates.
