MOSCOW, Russia / EuroWire.IO / – In Chelyabinsk this week, scientists from Russia and China announced the development of an ultrasonic welding technique that effectively doubles the strength of metal joints. The innovation not only boosts joint durability but also extends the lifespan of welded parts by 1.9 times. The project was led by researchers at South Ural State University in Chelyabinsk, in collaboration with Chinese colleagues. TV BRICS highlighted the findings, citing the university. This method is specifically designed for welding joints between dissimilar metals, such as steel and aluminium.
Engineers have long faced difficulties when joining different metals, as brittle intermetallic layers tend to form at the interface. These layers are prone to cracking under stress, weakening the entire structure. The new ultrasonic welding approach aims to mitigate this issue during spot welding, a common technique used in assembling car bodies and other metal structures. According to the university, the research results were published in Engineering Fracture Mechanics.
The process incorporates ultrasonic vibrations with approximately 1,200 watts of power into the spot welding procedure. This vibration refines the crystal structure within the weld, reducing the crystal size by nearly five times. Instead of coarse grains, the crystals become smaller and more uniform. Additionally, the method reduces the thickness of the brittle intermetallic layers at the joint by half, enhancing overall weld integrity.
Ultrasound eliminates trapped air bubbles in welds
Another benefit of ultrasonic application is the removal of air bubbles from the weld during the process, resulting in denser joints with fewer internal flaws. Testing revealed that the strength of the welded joints doubled through this method. The lifespan of the components was increased by 90%, or 1.9 times. The team indicated that these welds are more resilient against prolonged vibration and mechanical stress without cracking, which is crucial for components in moving vehicles.
The university did not provide specific strength metrics or detailed testing parameters in their announcement. The reported improvements are in relative terms. The researchers emphasized that this approach could significantly improve the reliability of structures composed of different metals. Since steel and aluminium are often paired to reduce weight while maintaining strength, weak joints have historically limited such applications. The project was conducted jointly with Chinese partners.
Potential applications in automotive, aerospace, and construction sectors
According to the researchers, this ultrasonic welding technique could be adapted for use in automotive, aerospace, and building industries. In vehicles, it could enable stronger bonds between steel safety cages and aluminium doors, bonnets, and wings. Lighter hybrid structures might allow electric cars to achieve greater range per charge. In aviation, lighter frames could carry more passengers or cargo while consuming less fuel. Achieving weight reduction remains a key objective for both industries.
In construction, this method could be applied to metal joints in bridges and skyscrapers. The university claims such joints could outperform traditional monolithic concrete in strength. The timeline for industrial implementation remains unannounced. South Ural State University has reported several applied research initiatives this year. The institution stated that the ultrasonic welding method opens up new avenues for creating lighter, yet more durable, structures.