Recent Development and Applications of Bulk Glassy Alloys

This paper reviews past developments and the present understanding of the physical and mechanical properties of glass alloys, with an emphasis on recent results obtained since around 1990, together with applications of bulk glassy alloys achieved mainly in Tohoku University. After introducing the fundamental concepts around glassy alloys in the first section, the second section describes the relationships between structural relaxation and the discoveries of glassy alloys with a large supercooled liquid region. The third section reviews the history of bulk glassy alloy development, followed by the bulk glassy alloy systems and their features in the fourth section and the features of a glassy structure in the fifth section. The sixth, seventh, and eighth sections summarize the engineering and standardization of Zr‐based bulk glassy alloys. Section nine and the 10th focus on the glass‐forming ability of Zr‐based hypoeutectic glassy alloys and Cu–Zr–Al–Ag bulk glassy alloys. The mechanical properties of Ni‐based bulk glass alloys at low temperatures are shown in the 11th section, whereas the 12th section describes the formation and properties of Ni‐free Ti‐based bulk glassy alloys. The 13th and 14th sections deal with porous Zr‐based bulk glassy alloys including spherical pores and commercialized Fe‐based glassy alloys, respectively, whereas the 15th section reviews supercoold liquid forming. Finally, applications for Zr‐, Ti‐, and Fe‐based glassy alloys are described in the 16th section. In conclusion, the 17th section attempts to assess the present knowledge of the structure and physical properties and identify some outstanding problems for future work.