Properties of hydrophobic carbon-PTFE composite coating with high corrosion resistance by facile preparation on pure Ti
(1. College of Metallurgy and Materials Engineering, Hunan University of Technology, Zhuzhou 412000, China;
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
3. Hunan Provincial Key Laboratory of Vehicle and Transmission System,
Hunan Institute of Engineering, Xiangtan 411104, China;
4. Hunan Gold Sky Aluminum Industry High-tech Co., Ltd., Changsha 410205, China)
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
3. Hunan Provincial Key Laboratory of Vehicle and Transmission System,
Hunan Institute of Engineering, Xiangtan 411104, China;
4. Hunan Gold Sky Aluminum Industry High-tech Co., Ltd., Changsha 410205, China)
Abstract: Composite coatings consisting of carbon and polytetrafluoroethylene (PTFE) were prepared on Ti alloy substrate by a simple two-step process of hydrothermal and impregnation. The morphology, composition, hydrophobic and corrosion properties of the composite coatings were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), water contact angle method, X-ray photoelectron spectroscopy (XPS) and electrochemical technique, respectively. The effect of PTFE content on the corrosion properties of the composite coatings was studied. It is found that the composite coating film exhibits a full coverage with uniformly distributed PTFE when 0.1 mol/L of glucose is used as carbon source and 20 wt.% PTFE suspension as impregnating solution. The coating with 20 wt.% PTFE has a good bonding strength with Ti plate and exhibits excellent hydrophobic property with a water contact angle of 142.3° as well as superior corrosion resistance with corrosion current density as low as 0.0045 μA/cm2. With regard to its excellent hydrophobicity and corrosion resistance, the carbon-PTFE composite coating may find potential application in automobiles and metal corrosion industries.
Key words: carbon coating; Ti plate; polytetrafluoroethylene; hydrothermal method; hydrophobicity; corrosion resistance