What are the Main Applications of Ultrasonic?
Power ultrasound is used in many different industrial processes and some unusual applications. We are actively exploring new areas of ultrasound applications. If you have not found any relevant applications on our website, please try to contact us.
Ultrasonic atomization spraying
Ultrasonic atomization is the use of ultrasonic energy to disperse water or liquid, forming liquid particles of several tens of micrometers in size, which are used for spraying, coating, granulation, etc. Compared to traditional pneumatic two fluid spraying, ultrasonic atomization spraying can achieve better uniformity, thinner coating thickness, and higher precision. The coating utilization rate of ultrasonic spraying is more than four times that of traditional two fluid spraying. Ultrasonic spraying equipment is mainly used for fuel cells, flux spraying, medical stent spraying, thin-film solar coatings, solar cells, graphene coatings, silicon photovoltaic cells, glass coating, etc.
Ultrasonic sonochemistry
Ultrasonic liquid processing equipment can cause ultrasonic cavitation of liquids under high-intensity ultrasound. It can be seen as a cloud of bubbles formed near the ultrasonic tool head, sounding like a strong hissing sound. Cavitation generates intense, asymmetric implosion of vacuum bubbles, causing micro jets with extremely strong mechanical shear forces. These forces are the ability of ultrasound to drive many physical and chemical processes forward. Ultrasonic energy acting on a medium can cause high-speed and subtle vibrations of particles, resulting in changes in mechanical quantities such as velocity, added sound pressure, and sound intensity, which act on extraction, crushing, emulsification, dispersion, defoaming, etc.
Ultrasonic target welding
Ultrasonic target welding machine is used for indium coating and backing plates of various targets such as ITO, Al, Mo, Cr, Si, etc. that do not use flux. Ultrasonic target welding machine can be used for surface coating of flat, inner and outer circular targets. Ultrasonic welding machines provide an environmentally friendly welding solution that does not use flux, and fundamentally avoids various problems of conventional flux welding, thereby providing stable and reliable welding.
Ultrasonic metal melt treatment
Ultrasonic welding is a method of joining without the use of soldering flux, in which high-frequency mechanical vibration replaces soldering flux. Mechanical vibration is transmitted to the liquid solder bath, and the energy of the mechanical vibration causes cavitation, thereby eroding the surface of the parts immersed in the bath. This can remove the oxide layer on the surface of the parts and allow the melted solder to wet the clean metal surface.
Ultrasonic cutting
A knife moves back and forth during the sawing action, at a rate of 30000 times per second. The distance of movement is very small, but the acceleration is so high that nothing can move or stick to the blade. Surgeons use ultrasonic surgical knives to make cuts without applying any pressure. Ultrasonic cutting tools can be used for products that are difficult to cut in other ways, such as food, plastic, rubber, etc.
The heat generated by ultrasonic vibration is also very useful. Some artificial fabrics are cut and sealed with ultrasonic knives to prevent wear and tear.
Ultrasonic cleaning
Cleaning is one of the earliest industrial applications of ultrasound. Place the object to be cleaned in a liquid bath vigorously stirred by multiple ultrasonic transducers. Depending on the application, the fluid can be water-based or solvent based. Traditionally, transducers are installed around the walls of cleaning tanks, but some modern devices use external transducers connected to resonant probes to transmit vibrations to the fluid.
Ultrasonic waves may affect the cleaning process in various ways. Rapid movement in fluids helps to wet surfaces, overcome surface tension, and may also help remove dirt particles and carry them away from the surface. Cavitation may be the most interesting (and effective) effect - the shock wave generated by the implosion of tiny steam bubbles can be devastating at close range. The bubbles are very small and can even penetrate the smallest gaps, making this process very suitable for parts that cannot be cleaned by other methods. Please also note that the process must be well controlled to minimize erosion on the surface of the cleaned parts. The standard test for ultrasonic intensity in a cleaning tank is to immerse a standard foil strip in it for a set time, then remove it and calculate the number of holes.
Ultrasonic metal welding
Ultrasonic waves can be used to weld different metals together without the need for solder and flux or special preparation. The difference between this process and plastic welding is that the two components vibrate parallel to the interface. This is a more intuitive and logical way to generate friction between them, but frictional heating is not considered the main mechanism of this process - the temperature required to melt (or even soften) most metals will be difficult to achieve. On the contrary, this mechanism is considered as diffusion bonding: when two surfaces are in close contact, atoms from each part will diffuse to the other part. Ultrasonic waves promote this close contact by decomposing the surface oxide layer, bringing the "primitive" metal into contact.
There are some limitations to this process. It is only suitable for relatively small components (a major example is welding connectors to car battery leads), as the power required to weld larger components will be higher than the actual power provided by this method. In addition, due to the need to use high clamping force and ultrasonic generators with serrated working surfaces to firmly grip the workpiece, this process often results in marking and deformation of the components.
Ultrasonic plastic welding
Plastic welding is used for a variety of products, from blister packaging, cardboard boxes, and small consumer goods to car fuel tanks and instrument panels. Its working principle is to accurately generate heat where it is needed - at the interface between the components to be connected. The component is sandwiched between the vibration ultrasonic generator and the fixed bracket. Strangely, vibrations are usually applied perpendicular to the contact surface, although most vibrations may be converted into in-plane motion. This has another advantage, that is, the clamping pressure will keep the ultrasonic generator in contact with the component - usually without the need for serrated surfaces. When the component is clamped close to the interface ("near-field" welding), the best results can be obtained, but if this is not possible, the process can still work from a distance ("riveting or insertion" is a variant of this process, in which a metal component (usually a threaded sleeve) is punched into a hole in a plastic component and then cured around the plastic component to form a permanent connection. This is a convenient method for manufacturing sturdy threaded holes in plastic components.
Ultrasonic processing
Ultrasonic waves have been used in various ways for metal processing. Lathe tools may benefit from intentionally induced vibrations to prevent "vibration" from damaging the surface finish of finished components. Ultrasonic drill bits are used for very hard ceramics, working by grinding or eroding materials - the liquid slurry around the drill bit contains loose hard particles that collide with the surface through vibration, eroding the material and producing more loose hard particles.
Ultrasonic metal forming
CarnaudMetalbox R&D (now part of Crown Cork and Seal - the world's largest packaging company) and Loughborough University have developed a new aerosol can that utilizes many innovative metal forming processes, starting with ultrasonic necking (i.e. reducing the diameter of the can) at one end. The advantage of using ultrasound in this situation is to minimize the friction between the can and the mold, thereby reducing the forming force. Without ultrasound, the force is so strong that the can body will bend and collapse during the necking process. The use of ultrasound can reduce the diameter of cans by 30% in one operation (in traditional necking processes, the maximum value is usually around 5%).
Ultrasonic waves are only effective when the vibration is perpendicular to the surface - for cylindrical tanks, this means developing a circular mold that will vibrate in the radial direction. Like other high-power applications, all tools must resonate, so the required resonance mode is uniform hoop expansion/contraction. We soon discovered that although designing a chip to resonate in this mode at the frequency of an ultrasonic device is quite easy, ruling out other vibration modes is a major challenge!
Another difficulty is that as the entire mold expands and contracts, there are no convenient nodes (stationary) available for installing it. This is solved by using a tubular installation system, which resonates at the same frequency as the mold itself.
The ultrasonic molding process has been put into production at a factory in the UK for the manufacture of small-diameter aerosol cans. The production line is still running intermittently, producing promotional packaging for several well-known customers. One of its products ("Fleurs de Paris" perfume demister) won the silver medal in the 1997 Metal Packaging Manufacturers Association Award.
Ultrasonic screening
Industrial sieves are typically stirred at low frequencies to help distribute products evenly on the surface and facilitate the passage of small particles. Vibrating the screen with ultrasonic frequency (in addition to this low-frequency oscillation) can significantly increase the flow rate, prevent product clogging of the holes in the screen, and help separate small particles from large particles.
Ultrasonic sintering
Powder metallurgy technology is used to manufacture high-quality steel and other metals. Before the sintering process begins, the powder must be packaged as tightly as possible to prevent the formation of voids or other defects in the finished product. Published research papers have shown that the use of ultrasound can significantly improve bulk density.
