Kumamoto University, Kyoto University, etc. KUMADAI Magnesium alloy formation mechanism

　The development of lightweight and sturdy materials for realizing an environmentally friendly society will become more and more important in the future from the viewpoint of reducing fuel consumption of vehicles. KUMADAI magnesium alloy is an alloy of magnesium, a small amount of zinc, and yttrium, and is expected to be applied to aircraft and biomaterials as a next-generation ultra-lightweight and high-strength material with the world's strongest strength.Looking at this at the atomic level, it is known that it has a complicated arrangement of atoms, but it was unclear how its structure was formed.

　The best way to elucidate how the arrangement of atoms is formed in metal is to take pictures of the movement of atoms frame by frame.By quenching the molten alloy, it can be solidified while the atoms are moving.Furthermore, by heating to a temperature slightly lower than the melting point, the atoms move slowly.By repeating the operation of moving it a little and hardening it, we succeeded in observing the changing state frame by frame.This frame by frame was measured with the measuring device of the High Energy Accelerator Research Organization (KEK).As a result, we succeeded in observing a two-step change in which the atoms of yttrium and zinc form a small mass in magnesium and then the mass is neatly aligned.

　The elucidation of the formation mechanism of sturdy materials will lead to research aimed at further improving functionality.In addition, there have been no reports of changes in the state of metal in these two stages.By analyzing this in more detail, we can expect to find new knowledge about the phenomenon that the arrangement of atoms changes in a solid.