MOSCOW, Russia / EuroWire.IO / – A novel ultrasonic welding approach, developed through collaboration between Russian and Chinese researchers, has demonstrated the ability to extend the lifespan of metal components by 1.9 times. Additionally, this technology effectively doubles the tensile strength of welded joints, according to South Ural State University. The team at Chelyabinsk, in partnership with colleagues from China, created this process, which is suitable for metals with varying characteristics, as reported by TV BRICS on October 19, citing the university.
Typically, combinations such as steel and aluminium are prone to forming brittle interlayers at the weld interface, which can compromise the joint’s integrity by causing fractures, especially under vibrational or cyclic mechanical stresses. The new method mitigates this issue by refining the weld’s microstructure during the spot welding process. The university indicated that their findings were published in the journal Engineering Fracture Mechanics, though they did not specify the individual researchers involved.
This process involves the application of ultrasonic waves with an intensity around 1,200 watts during the formation of the spot weld. According to Rossiyskaya Gazeta, these waves are transmitted through the heating electrodes, and the vibration disrupts the crystal lattice of the metal, resulting in a reduction of crystal size by nearly five times. Consequently, the brittle interlayers become half as thick, producing a more uniform weld that is less susceptible to cracking, which significantly enhances overall joint quality.
Denser welds resist vibration and improve durability
The ultrasonic energy also serves to eliminate trapped air pockets, resulting in a more compact and dense weld. Testing revealed that these joints exhibit twice the strength of conventional welds, with the operational lifespan of the components increasing by 90%. The researchers emphasized that the enhanced welds can endure prolonged periods of vibration and mechanical stress without cracking. This improvement is particularly relevant for automotive, aerospace, and construction industries, where repeated load cycles often lead to fatigue failure at weld locations.
While the university’s announcement highlights the relative improvements, it does not specify the absolute strength metrics, the specific alloy grades involved, or the number of samples tested. Several Russian universities have reported engaging in various materials research initiatives this year, including studies on coatings for titanium implants. South Ural State University has also developed a berberine-enriched cheese aimed at boosting immunity. The timeline for commercial application of this welding method remains unspecified by the university.
Potential uses in transportation and construction sectors
The research team envisions applications across the automotive, aerospace, and civil engineering fields, where this technology could enable the creation of lighter, more durable structures. For instance, automakers might join steel passenger compartments with aluminium doors, bonnets, and wings into a unified hybrid shell, reducing weight and increasing electric vehicle range. In aviation, lighter airliners capable of carrying additional passengers or cargo could be developed, which would also lead to lower fuel consumption per flight.
In civil engineering, the method could be utilized in constructing bridges and tall buildings, with welded joints potentially surpassing the strength of monolithic concrete in some applications. Examples include bonding a steel column to an aluminium panel or welding a steel longeron to an aluminium subframe. The project was conducted collaboratively between Russia and China, and the university stated that this technique paves the way for creating structures that are both lighter and stronger across multiple industries.