金属ガラスの応用・基礎研究の紹介;製品の開発とぜい性改善への挑戦

抄録

Metallic glasses exhibit a high mechanical strength at room temperature and superior formability in a supercooled liquid region, which make them to become promising materials for engineering applications. However, two major drawbacks, one is difficulty in fabricating bulk samples and the other is their intrinsic brittle properties during fracture, highly limited their practical applications. With respect to the former, we focused on fabricating micrometer size products and a Fe-based metallic glassy micro gear was successfully developed through our newly proposed microparts fabrication process. For the latter, a concept of amorphous/glassy state gradient is introduced, intending to improve a brittleness by controlling the crack propagation path depending on a created gradient state. The temperature/thermal history gradient is thermally introduced within a single monolithic Zr-based metallic glass, and it was found that a brittleness presumably improved by thermally created amorphous/glassy state gradient.