Stability and Icosahedral Transformation of Supercooled Liquid in Metal-Metal type Bulk Glassy Alloys
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LL6.1.1/MM4.1.1
Stability and Icosahedral Transformation of Supercooled Liquid in Metal-Metal type Bulk Glassy Alloys Akihisa Inoue, Wei Zhnag1, Dmitri V. Louzguine, Junji Saida2 and Eiichiro Matsubara Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan 1 Japan Science and Technology Agency, Sendai 980-8577, Japan 2 Center for Interdiciplinary Research, Tohoku University, Sendai 980-8578, Japan ABSTRACT The glassy structure and the primary precipitation phase from supercooled liquid were examined in metal-metal type Zr-, Hf- and Cu-based alloy systems by various advanced analytical techniques. The icosahedral phase precipitates as the primary phase from supercooled liquid for all the metal-metal type glassy alloys examined in the present study. The icosahedral phase has a rhombic triacontahedra type for the Zr-Al-Ni-Cu-NM (NM=Ag, Pd, Au, Pt), Zr-Cu-NM, Hf-Al-Ni-Cu-NM, Cu-Zr-Ti-Pd and Cu-Hf-Ti alloys. In addition, the short-range atomic configurations in their glassy alloys have the features of highly dense packed atomic configuration, new local atomic configurations and long-range homogeneity with attractive interaction. It is therefore concluded that the high glass-forming ability of the metal-metal type alloys is due to the self-formation of the unique glassy structure with the above-described three features which are consistent with the formation of short-range icosahedral atomic configuration. BULK GLASS FORMATION AND BULK GLASSY ALLOY SYSTEMS Since 1990, bulk glassy alloys with various outer shapes have been produced in a number of alloy systems such as Mg- [1], La- [2], Zr- [3,4], Ti- [5], Fe- [6], Pd-Cu- [7], Co- [8], Ni- [9], Cu[10-12] and Ca- [13]bases by various casting techniques. Even in a laboratory scale, we Table I. Typical bulk gassy alloy systems reported up to date together with the calendar years when the first paper or patent of each alloy system was published. 1. Nonferrous alloy systems Mg-Ln-M (Ln=lanthanide metal, M=Ni,Cu,Zn) Ln-Al-TM (TM=VI ~ VIII group transi. metal) Ln-Ga-TM Zr-Al-TM Ti-Zr-TM Zr-Ti-TM-Be Zr-(Ti,Nb,Pd)-Al-TM Pd-Cu-Ni-P Pd-Ni-Fe-P Ti-Ni-Cu-Sn Cu-(Zr,Hf)-Ti Cu-Zr, Cu-Hf Cu-(Zr,Hf)-Ti-(Y,Be) Cu-(Zr,Hf)-Ti-(Fe,Co,Ni) Ca-Mg-Ag-Cu Cu-(Zr,Hf)-Al Cu-(Zr,Hf)-Al-(Ag,Pd)
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2. Ferrous alloy systems
Year
1988 1989 1989 1990 1993 1993 1995 1996 1996 1998 2001 2001 2001 2002 2002 2003 2003
Fe-(Al,Ga)-(P,C,B,Si,Ge) Fe-(Nb,Mo)-(Al,Ga)-(P,B,Si) Co-(Al,Ga)-(P,B,Si) Fe-(Zr,Hf,Nb)-B Co-(Zr,Hf,Nb)-B Fe-Co-Ln-B Fe-Ga-(Cr,Mo)-(P,C,B) Fe-(Nb,Cr,Mo)-(C,B) Ni-(Nb,Cr,Mo)-(P,B) Co-Ta-B Fe-Ga-(P,B) Ni-Zr-Ti-Sn-Si Ni-(Nb,Ta)-Zr-Ti Fe-B-Si-Nb Co-Fe-B-Si-Nb Co-Fe-Ta-B Ni-Nb-Sn
1995 1995 1996 1996 1996 1998 1999 1999 1999 1999 2000 2001 2002 2002 2002 2003 2003
LL6.1.2/MM4.1.2
Figure 1. Features of alloy components and short-range atomic configurations for stabilization of supercooled liquid and high glass-forming ability. have produced bulk glassy alloys with different outer shapes such as massive ingots with a diameter of 75 mm and a height of 80 mm [14], cylindrical r
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