摘要
Abstract
Magnesium alloy has the advantages of low density,high specific strength,excellent electromagnetic shielding performance and good biocompatibility,making it a promising structural material in aerospace,automobile manufacturing,electronic devices,biomedicine and other fields.However,its development has been hindered by inadequate corrosion resistance in application environments.In recent years,in order to address the severe corrosion issues of magnesium alloys in practical applications,the emerging material metal-organic frameworks(MOFs)has been extensively utilized for surface modification.MOFs consist of the metal centers and the organic ligands,offering high specific surface area,abundant active sites,controllable structure composition,and easy functionalization,thus making them a superior new type of corrosion-resistant material.The work aims to present a comprehensive review on the recent preparation methods and the corrosion-resistant applications of MOFs on magnesium alloys.The synthesis of MOFs on magnesium alloys can be classified into two primary methods,including powder preparation and in-situ synthesis.The main difference between these two methods lies in whether the MOFs are prepared as powders or grown directly on the surface of the magnesium alloy.This difference is crucial as it impacts the final properties and applications of the resulting MOFs.The advantages and disadvantages of these two methods are discussed in detail,along with the most common synthetic techniques,such as the deposition method,the solvothermal method,and the electrochemical method.Each method has its unique benefits and drawbacks,making it necessary to carefully consider the specific requirements of each application when a synthesis method is adopted.The application of MOFs materials is discussed for the corrosion protection of magnesium alloys,encompassing corrosion inhibitors,protective coatings,fillers,and nano-containers.The utilization of MOFs with corrosion-inhibiting properties requires careful selection of the metal centers and the organic ligands.Several MOFs has been employed as corrosion inhibitors in engine coolants to reduce the corrosion rate of magnesium-based engines.Extensive data presented by researchers demonstrate the enhanced corrosion resistance achieved through the use of MOFs,including the electrochemical impedance and the corrosion current density measurements.Additionally,the MOFs materials can be directly applied as corrosion-resistant coatings.However,the weak adhesion between the MOFs coating and the magnesium alloy is observed due to the rapid corrosion rate of the magnesium alloy.To improve the adhesion strength,the MOFs coatings are typically prepared on a surface film composed of oxides or hydroxides.Furthermore,MOFs materials can serve as fillers or nano-containers in coatings.The addition of MOFs not only increases the tortuosity of the corrosion pathway but also enhances the compatibility and the dispersion of MOFs within most organic coatings.As nano-containers,certain types of MOFs exhibit pH-responsive characteristics that enable them to effectively respond to the external stimuli and prolong the service life of coatings by reducing the waste of corrosion inhibitors.Some specific types of MOFs exhibit hydrophobicity which diminishes the contact between the coating and the aggressive water environments,thus slowing down the corrosion rate of magnesium alloys.Finally,the challenges of using MOFs as corrosion-resistant materials are summarized,including limited types with corrosion inhibition properties,difficulties in heterogeneous nucleation,and thin coating thicknesses.Despite these challenges,the potential application of MOFs materials is promising in protecting magnesium alloys against corrosion.It is necessary to carry out further research on optimizing their properties and broadening their application on the surface of metallic materials.关键词
镁合金/金属有机框架/防腐材料/涂层/填料/纳米容器Key words
magnesium alloy/metal-organic framework/corrosion-resistant material/coating/filler/nano-container分类
金属材料
