Desire for stronger and more durable metals, researchers continue to explore innovative technologies. One such effort, deep into the metallurgical world, revolves around the pursuit of improving the characteristics of steel, is the core of our modern infrastructure. From towering skyscrapers to important machinery, Steel’s role is everywhere, making its strength and resilience a crucial subject. This pursuit of steel therapy proves the indomitable human spirit to push the boundaries of materials science and strive to seek progress that echoes through various industries and applications.
The study was led by Professor Yoshimura and his colleagues Dr. Yamamoto and Dr. Shintaro Yamamoto and Hayato Watanabe of Sanyo-Onoda City University in Japan, which has made a significant leap in the field of metalworking. The study, published in the journal Materials Results, introduces an innovative metal processing technology, positron and laser-assisted magnetic energy-intensive multifunctional cavitation (PLMEI-MFC), which significantly advances the treatment of SCM440 CR-MO steel.
This method uses narrow nozzles to create water-jet bubbles and then sonicates in a magnetic field. These cavitation clouds are then irradiated by laser beams, including ultraviolet light, thereby enhancing their impact on the steel. The integration of positron irradiation into this process is a game-changer because it greatly enhances the surface strength of the steel.
Dr. Yoshimura’s team found that small WJC bubbles generated by narrow nozzles are key to achieving high compression residual stress and strong hardness in steel. “Using a narrow nozzle during this process produces small WJC bubbles, which is crucial to achieving high compression stress and significant hardness of the metal,” explains Dr. Yoshimura.
Positron radiation in this process plays a key role in changing the properties of steel. “Incorporating positron radiation significantly increases the compression residual stress of 1160 MPa, effectively converting tensile residual stress into compression residual stress,” said Dr. Yoshimura. This conversion is critical to improving metal resistance to fatigue and rupture. important, thus extending its useful life.
The research group’s approach is meticulous. They first carried out the steel specimens in a multifunctional cavitation process. They then measured residual stress using a portable X-ray device, which accurately determined the changes brought about by the treatment. The surface morphology and roughness were then evaluated using a three-dimensional laser microscope, which gave a clear understanding of the enhancement on the steel surface. Finally, micromagnetic hardness measurements were performed to quantify the improvement of hardness, which is a key factor in determining the suitability of steel for a variety of applications.
The findings of this study are not only a step in materials science. They represent leap. The method developed by Dr. Yoshimura and his team have developed new avenues for metal treatment, providing a method that can significantly improve the strength and durability of steel without damaging its surface quality. The potential applications of this study are broad, from the automotive and aerospace industries to construction and machinery, where the strength, life and reliability of metal components are critical.
In short, the research of Professor Yoshimura and his team at Sanyo-Onoda City University paves the way for new, innovative metalworking methods. Their work demonstrates the power of scientific inquiry and its ability to drive technological advancement.
Journal Reference
Yoshimura, T., Yamamoto, S., Watanabe, H. , “Using energy-intensive multifunctional cavitation combined with narrow nozzles and positron radiation using precise peeling of CR-MO steel,” Material 20 (2023) 100463. : https://doi.org/10.1016/j.rinma.2023.100463.
About the author
Toshihiko Yoshimura
Sanyo-Onoda City University, Japan
He received his degree in engineering doctor from Tokyo Institute of Technology in 1995. Materials engineering expert, he won the paper award from the Japan Vacuum Society, the Japan Water Flow Technology Society and the Japan Mechanical Engineers Association Technology Award.
