Author: Bo Liang, Baoyan Zhang, Guodong Wang, Di Li,Xiaoming Zhang
Institute: Center for Molecular Science and Engineering, Northeast University, Shenyang 110819, China
In recent decades, the problem of corrosion of metal materials, especially aluminum-based alloys, has become particularly relevant. In this context, sol-gel technology has proven itself as a promising method for producing protective coatings. The use of ultrasonic irradiation in the process of forming protective structures can significantly improve the properties of the resulting materials.
The Al65Cu20Fe15 alloy, with its unique mechanical and corrosion characteristics, requires a special approach to protection. Ultrasound, acting in the process of coagulation of sol-gel elements, promotes a more uniform distribution of nanoparticles and improves the interaction between them. As a result, a dense and uniform coating is formed, capable of effectively resisting aggressive environments.
The experiments showed that the use of ultrasonic irradiation leads to an increase in the adhesion of the coating and a significant decrease in corrosion activity. In this case, not only the improvement of mechanical properties is observed, but also an increase in the wear resistance of the protective layers. Thus, the method of ultrasonic irradiation in sol-gel technology significantly expands the possibilities of protecting Al65Cu20Fe15 alloys from corrosion, opening up new horizons for their use in industry.
Al65Cu20Fe15 alloy powder was encapsulated using a conventional sol-gel method, where tetraethoxysilane (TEOS) served as a precursor to improve its corrosion resistance. The process optimization was based on nine carefully designed orthogonal experiments (L9), considering four key parameters: reaction temperature, ethylenediamine concentration, TEOS concentration, and feed method. Visual analysis showed that the optimal conditions were achieved. Based on the obtained data, ultrasound-assisted encapsulation was performed. The effect of ultrasound amplitude and treatment time on the encapsulation efficiency was investigated. Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, dynamic light scattering, and energy dispersive analysis were used to characterize the sample. As a result, the corrosion inhibition of the encapsulated powder was 99.3% in an acidic environment with pH 1, and the average particle size (d50) increased by only 4.8% compared to the original powder, indicating the presence of a thin silicon film on its surface.
Quasicrystals have low friction properties and are widely used as additives to lubricants. There are a number of methods for encapsulating inorganic powders, including chemical precipitation, polymerization, and sol-gel. The sol-gel method is distinguished by low reaction temperatures and excellent adhesion to metal surfaces, making it attractive for anti-corrosion coatings. However, traditional technology faces the problem of forming unwanted colloidal particles. Ultrasonic irradiation can create an effective environment for reducing the number of these particles. This paper shows that the amplitude and duration of ultrasound exposure significantly affect encapsulation, which may be applicable to other systems.