How can supersonic spraying overcome technological limitations and achieve dual improvements in coating quality and spraying efficiency?

How can supersonic spraying overcome technological limitations and achieve dual improvements in coating quality and spraying efficiency?

Supersonic spraying, as a key technology for material surface strengthening and modification, is widely used in many industrial fields. However, traditional supersonic spraying technology has limitations such as poor coating quality and low spraying efficiency. Nowadays, through technological innovation and optimization, this technology is gradually breaking through bottlenecks and achieving dual improvements in coating quality and spraying efficiency.

Innovate spraying equipment and processes

Optimize spray gun design

Spray gun is the core of supersonic spraying equipment. The traditional spray gun has shortcomings in fully heating and accelerating the particles of the sprayed material. The new design focuses on optimizing the combustion chamber, Laval nozzle, and equal cross-sectional length nozzle structure. For example, improving the shape and size of the combustion chamber allows for more thorough mixing of fuel and combustion gases, more intense combustion, and the release of more energy for heating and accelerating particles. Refine the design of the Laval nozzle, precisely control the flame acceleration process, improve particle velocity and flight stability, enable particles to impact the substrate surface more uniformly and at high speeds, and enhance the density and bonding strength of the coating.

Improve spraying process parameters

Process parameters have a significant impact on coating quality and spraying efficiency. Determine the optimal parameter combination for different spraying materials and working conditions through extensive experiments and simulation analysis. Taking the spraying distance as an example, if the distance is too small, the coating is prone to decarburization due to overheating decomposition, and if the thermal stress is too high, it will also reduce the bonding strength; If the distance is too large, the particle velocity will decrease and the coating density will deteriorate. Finding the appropriate spraying distance and matching it with the appropriate powder feeding rate can not only improve the coating density and bonding strength, but also reduce the oxide content. At the same time, precise control of fuel and combustion supporting gas flow rates, pressures, and other parameters can optimize the combustion process, improve energy utilization efficiency, and enhance spraying efficiency.

Develop new spray coating materials

Developing high-performance powder materials

Developing powder materials with special properties can improve coating quality and spraying efficiency. For example, for powder materials added with nano rare earth elements, the nano powder is hard and tough, and the rare earth elements further enhance the wear resistance, fill the porosity, and improve the corrosion resistance. This material can reduce the wear rate and extend the service life of the coating. Developing powder materials that can quickly melt at lower temperatures and bond well with the substrate can reduce thermal impact on the substrate, lower energy consumption, and improve spraying efficiency.

Design composite coating materials

Composite materials with different properties to design coatings that combine multiple good properties. If metal is combined with ceramic materials, the coating can have both the toughness and conductivity of metal and the high hardness, wear resistance, and high temperature resistance of ceramic. By reasonably controlling the composite ratio and structure, optimizing the comprehensive performance of the coating, meeting the requirements of complex working conditions, reducing coating thickness, shortening spraying time, and indirectly improving spraying efficiency.

Introduce good control and monitoring technologies

Realize intelligent control

By utilizing automation and intelligent technology, precise control of the supersonic spraying process can be achieved. By using sensors to monitor key parameters during the spraying process in real-time, such as particle velocity, temperature, flow rate, etc., the data is fed back to the control system. The control system automatically adjusts the operating status of the equipment based on preset parameters and real-time feedback to ensure stable spraying process. For example, when the particle velocity fluctuates, the system automatically adjusts the flow rates of fuel and combustion assisting gas to maintain stable particle velocity and ensure consistent coating quality.

Strengthen process monitoring and quality inspection

Using good monitoring methods, such as high-speed cameras, infrared thermal imaging, etc., to observe the spraying process in real time and detect abnormalities in a timely manner. High speed cameras can capture the trajectory of particle flight and the instantaneous state of impact on the substrate, providing a basis for analyzing the process of coating formation; Infrared thermography can monitor the temperature distribution on the surface of coatings and promptly detect areas of overheating or uneven temperature. Establish coating quality inspection methods, such as using ultrasonic testing, X-ray diffraction and other technologies, to detect internal defects, organizational structure and composition of coatings, ensure coating quality meets requirements, avoid rework due to quality problems, and improve overall efficiency.