Search

A novel water-based rust conversion agent (abbreviated as “TE-GAE”) was firstly synthesized using gallic acid (3,4,5-Trihydroxybenzoic acid, abbreviated as “GA”) and triethanolamine (abbreviated as “TE”) by esterification reaction. A new type of rust conversion coating (abbreviated as “TE-GAE coating”) containing the TE-GAE and additives was also prepared. The structural feature of rust conversion agent TE-GAE was characterized using Fourier transform infrared spectrum (FT-IR). The effect of the synthetic water-based TE-GAE coating on original rust layer were investigated by X-ray diffractometer (XRD) and Scanning electron microscope (SEM). Compared with traditional rust conversion coatings that apply tannic acid and phosphoric acid as rust converters, the as-synthesized integrated TE-GAE coating firstly revolutionized the application method of the anti-corrosion coatings, combined the traditional “primer” and “topcoat” into one, and improved engineering efficiency while ensuring protective effect. Additionally, the adhesion test indicated that the integrated TE-GAE coating presented remarkably strong film adhesion between the coating and steel substrate. Meanwhile, the neutral salt spray test and weather-resistant test showed significant corrosion resistance. Furthermore, a corrosion resistance mechanism including the combined effect of the rust conversion, barrier and corrosion inhibition for the integrated TE-GAE coating was tentatively proposed, which indicating that the rust converter chelates with Fe2+/Fe3+ to form a dense chelating film, extend the penetration path of corrosive medium and delay the occurrence of corrosion process. Thus, such a “green” and “efficient” integrated rust conversion coating is promising for protecting steel from corrosion, which is critical for the sustainable development of functional coating materials.

As an efficient cooling method for high heat flux, spray cooling has a great application potential on aircraft directed energy weapon cooling. Based on the analysis of previous research results, an experimental system of open loop spray cooling was established. Four different surfaces and two additives were applied and spray cooling performance including surface heat flux, surface temperature and heat transfer coefficient was experimentally investigated with water as the cooling medium. The experimental results indicate that among the four surfaces, drilling surface has the highest heat transfer coefficient and combined surface has the highest cooling efficiency. Meanwhile heat transfer can be enhanced by adding potassium chloride to a certain concentration and then deteriorated with higher concentration; heat transfer is deteriorated with the increase of ethylene glycol concentration. Therefore for aircraft spray cooling system combined surface should be applied for its advantages of low surface temperature and high cooling efficiency while ethylene glycol is preferred to improve the application range of the system in consideration of the corrosion of salt solution.