MOSCOW, Russia / EuroWire.IO / – In Chelyabinsk, scientists from Russia and China have pioneered an ultrasonic welding innovation that doubles the durability of metal connections. This approach also increases the lifespan of welded parts by 1.9 times. The project was spearheaded by researchers at South Ural State University and involved collaboration with Chinese colleagues. The results, as reported by TV BRICS, were based on the university’s findings. The new method is specifically designed to enhance joints between dissimilar metals such as steel and aluminium.
For decades, connecting different types of metals has posed significant engineering challenges. Typically, brittle intermetallic layers tend to form where steel and aluminium meet, which can crack under stress and compromise the structure. The latest technique aims to mitigate this issue during spot welding, a process commonly used in manufacturing car bodies and other assemblies. The university announced that their research has been published in Engineering Fracture Mechanics.
The process incorporates ultrasonic vibrations with an output of approximately 1,200 watts into the standard spot welding procedure. This vibration refines the internal crystal structure of the metal within the weld zone. According to the university, the size of the crystals decreases by nearly five times, resulting in smaller, more uniform structures instead of coarse ones. Additionally, this process reduces the thickness of the brittle intermetallic layers at the joint by half, enhancing overall strength.
Ultrasound Eliminates Air Entrapment in Welds
Beyond crystal refinement, the ultrasound application expels trapped air bubbles from the weld during the process. This results in more solid, defect-free joints with increased density. Testing revealed that the strength of these welds doubled when employing the new ultrasonic technique. Furthermore, the longevity of the welded components improved by 90%, or 1.9 times. The team noted that these welds better resist prolonged vibration and mechanical loads without cracking, which is crucial for parts in moving vehicles.
In its announcement, the university did not specify absolute values for the ultimate strength nor detailed test conditions; rather, the improvements were presented as relative gains. The researchers characterized this method as a means to enhance the reliability of hybrid metal structures. Since steel and aluminium are often combined to reduce weight while maintaining strength, weak joints have historically limited such designs. This research was conducted as a collaborative effort with Chinese scientists.
Potential Impact on Lightweight Vehicles, Aircraft, and Construction
Looking ahead, the team believes their ultrasonic welding approach could find applications across the automotive, aerospace, and construction sectors. In automotive manufacturing, it might enable stronger bonds between steel safety cages and aluminium doors, bonnets, or wings. This could facilitate the creation of lighter hybrid bodies, allowing electric vehicles to achieve greater range per charge. In aviation, lighter aircraft frames could carry more passengers or cargo, reducing fuel consumption. Achieving weight reduction remains a key objective for both industries.
In the building sector, this method could be employed to join metal components in bridges and skyscrapers, with the university suggesting such joints could outperform monolithic concrete in strength. Although the team has not specified when this technology might enter widespread industrial use, South Ural State University has recently announced several applied research initiatives. The university emphasized that this ultrasonic welding technique opens up new avenues for constructing lighter yet stronger structures.