On March 3, the research group of Assistant Professor Motomichi Koyama, Professor Hiroshi Noguchi, and Professor Kaneaki Tsuzaki of the Department of Mechanical Engineering, Graduate School of Engineering, Kyushu University, said that crack propagation was suppressed by a sticky break like the bones of animals. The company announced that it has found a steel that exhibits epoch-making fatigue characteristics with a significantly extended fatigue life.
Metal fatigue fracture leads to fracture In metal fatigue fracture, even if the force applied at one time is small, it is repeated many times to generate minute cracks on the surface of the material, which expand and propagate and gradually spread to fracture. ..Correct understanding and evaluation of the properties of this metal is extremely important in preventing damage to equipment and machinery.
The research group focused on the relationship between the local mechanical state at the crack tip and the metal microstructure in order to suppress the generation and propagation of fatigue cracks.And, because the metal microstructure of the hierarchical atomic group including the layered morphology causes a sticky break like the bone of an animal, crack propagation is suppressed and the fatigue life is extended, which is an epoch-making fatigue characteristic. Found the steel shown.
This result is expected to bring new developments to both metal physics and fracture mechanics that analyze mechanical states, which contribute to the development of metallic materials with excellent mechanical properties such as fatigue, as well as contributions in terms of application and practical use. It is supposed to be done.
