Preparation of metal organic framework film on surface of aluminum profile and properties of fluorocarbon powder coating

The chemical pretreatment film on the surface of aluminum profile,the type of fluorocarbon powder and the compatibility between them are the common key problems in the industry of using"powder"instead of"paint"to solve the volatile organic compounds(VOCs)and related organic wastewater discharge in the coating process.In this study,a new type of pretreatment film was prepared on the surface of aluminum profile.It was found that the prepared pretreatment film had a three-dimensional framework s tructure,and the organic matter and titanium salt were connected by the introduction of divalent metal ions to form a metal skeleton film.

Nickel-free sealing technology for anodic oxidation film of aluminum alloy at room temperature

Different additives were added into the potassium fluorozirconate solution to prepare different nickelfree sealing reagents,with which the anodic oxidation film of aluminum alloy was sealed at room temperature.The phosphor chromic acid weight loss method was used to evaluate the sealing effects.Using electron scanning microscopy(SEM),the surface and cross-sectional micromorphologies of the anodic oxidation films sealed by different fluorozirconate sealants were observed.The position and state of zirconium element distribution in the film hole were investigated by the further quantitative and distribution analysis of Zr element.This study provides an experimental evidence for the theoretical studies of fluorozirconate-sealed anodic oxidation films.It is shown that the fluorozirconate has good sealing effects and has a wide prospect for sealing the aluminum alloy samples.Its products were highly corrosion resistant,and were filled in the openings of the micropores in the oxide film.

Characteristics of Ce-Mn film on 6061 alloys and its improved performance

HF2- was applied to accelerate the Ce-Mn film formation on 6061A1 alloy in the Ce3+-MnO4-solution.The process of film formation,the composition and structure of the film were analyzed by scanning electron microscopy(SEM) equipped with energy-dispersive spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS)and X-ray diffractometer(XRD).The film formation process includes three stages.At the initial stage,a threedimensional(3D) skeleton was formed quickly,and then the skeleton was fully filled with cerium oxide and manganese oxide,resulting in a dense structure.Subsequently,a new skeleton was formed and also filled.Al,Ce,O and Mn were detected in the film.Ce existed mainly in the form of Ce4+(89%).The film existed in an amorphous form and was composed of ceria(cerium hydroxide),manganese dioxide and aluminum oxide.After electrostatically spraying fluorocarbon powder,the resultant products satisfied the required mechanical performance and exhibited almost non-filament corrosion compared with commercially available chromium-free conversion film.Its corrosion resistant time to acetate spray can reach 2000 h,which is consistent with that of fluorocarbon paint.The results showed that Ce-Mn film can offer an attractive prospect to eliminate volatile organic compounds(VOC) problem arisen by using fluorocarbon paint in the process of industrial production.