MOSCOW, Russia / EuroWire.IO / – Researchers from Russia and China have created an ultrasonic welding process that doubles the tensile strength of metal connections. This innovative approach also increases the lifespan of welded parts by 1.9 times. The project was spearheaded by scientists at South Ural State University in Chelyabinsk, in collaboration with Chinese colleagues. TV BRICS reported the findings, citing the university. The method specifically targets joints between metals with differing characteristics, such as steel and aluminium.
Fusing dissimilar metals has long posed difficulties for engineers. The formation of brittle intermetallic layers at the contact points often causes cracking under stress. These layers weaken the overall structure. The new process aims to mitigate that issue during spot welding, which is common in manufacturing car bodies and other assemblies. The university stated the research was published in Engineering Fracture Mechanics.
The method incorporates ultrasonic vibrations with approximately 1,200 watts of power into the spot welding procedure. This vibration refines the internal crystal structure of the metal within the weld. According to the university, the crystal size decreases by nearly five times. The crystals become smaller and more uniform, replacing coarse grains. Additionally, the process cuts the thickness of the brittle intermetallic layers in half at the joint interface.
Ultrasound Eliminates Air Bubbles in Welds
The ultrasound also forces air bubbles out of the metal during welding. This results in denser welds with fewer internal flaws. Tests demonstrated that joint strength was doubled using the new technique. The components’ service life increased by 90%, or 1.9 times. The scientists noted that these welds are better equipped to resist prolonged vibration and mechanical stress without cracking. Such durability is essential for parts in moving vehicles.
The university did not disclose exact strength measurements or detailed testing parameters in its announcement. The improvements were described in relative terms. The scientists explained that their approach aims to improve the reliability of hybrid-metal structures. Combining steel and aluminium is common to reduce weight while maintaining strength. Previously, weak joints limited the potential of such designs. The project was a joint effort with Chinese researchers.
Potential for Lighter Vehicles, Aircraft, and Buildings
The scientists believe the technology could be applied in automotive, aerospace, and construction sectors. In cars, it could help attach a steel safety cage to aluminium doors, bonnets, and wings. Lighter hybrid bodies might enable electric vehicles to travel further on a single charge. In aviation, lighter airframes could carry more passengers or cargo while consuming less fuel. Weight reduction is a major focus for both industries.
In construction, the method may be used to create metal joints in bridges and skyscrapers. The university mentioned that such joints could be stronger than monolithic concrete. The timing for industrial adoption remains unclear. South Ural State University has reported several applied research initiatives this year. The university emphasized that this method opens new opportunities for developing lighter, stronger structures.