Glass and Quasicrystal Formation in a Zr-based Multicomponent Alloy

The phase formation of a Zr 57 Ti 8 Nb 2.5 Cu 13.9 Ni 11.1 Al 7.5 alloy has been investigated upon cooling from the melt at different quenching rates as well as upon annealing of as-cast specimens. The different samples are characterized by x-ray diffraction, transmission electron microscopy and differential scanning calorimetry. Rapid quenching using the melt spinning technique results in amorphization. Slower cooling as realized upon copper mold casting leads to an icosaheadral quasicrystalline phase coexisting with a small amount of amorphous phase. The primarily formed quasicrystals have a grain size of about 1 νm. Upon annealing, the amorphous phase formed upon melt spinning precipitates quasicrystals in the first step of a series of transformations to the crystalline equilibrium compounds. The quasicrystals formed by annealing do not exceed a size of 5 to 10 nm.

[1]  J. Eckert,et al.  As-cast quasicrystalline phase in a Zr-based multicomponent bulk alloy , 2000 .

[2]  S. Yi,et al.  Stability and phase transformations of icosahedral phase in a 41.5Zr41.5Ti17Ni alloy , 2000 .

[3]  A. Inoue,et al.  Mechanical Properties of Bulk Amorphous Zr-Al-Cu-Ni-Ag Alloys Containing Nanoscale Quasicrystalline Particles , 1999 .

[4]  Tao Zhang,et al.  High Strength and Good Ductility of Bulk Quasicrystalline Base Alloys in Zr 65 Al 7.5 Ni 10 Cu 17.5− x Pd x System , 1999 .

[5]  A. Inoue,et al.  Quasicrystals in a partially devitrified Zr65Al7.5Ni10Cu12.5Ag5 bulk metallic glass , 1999 .

[6]  W. Johnson,et al.  Large supercooled liquid region and phase separation in the Zr–Ti–Ni–Cu–Be bulk metallic glasses , 1999 .

[7]  W. Johnson,et al.  Mechanical properties of Zr_57Nb_5Al_10Cu_15.4Ni_12.6 metallic glass matrix particulate composites , 1999 .

[8]  J. Eckert,et al.  Effect of cooling rate on the precipitation of quasicrystals from the Zr–Cu–Al–Ni–Ti amorphous alloy , 1998 .

[9]  R. Stroud,et al.  A stable Ti-based quasicrystal , 1997 .

[10]  L. Schultz,et al.  Electrochemical investigations on the bulk glass forming Zr55Cu30Al10Ni5 alloy , 1997 .

[11]  W. Johnson,et al.  Effect of Oxygen Impurity on Crystallization of an Undercooled Bulk Glass Forming Zr–Ti–Cu–Ni–Al Alloy , 1997 .

[12]  S. Roos,et al.  Formation of quasicrystals in bulk glass forming Zr–Cu–Ni–Al alloys , 1996 .

[13]  A. Inoue,et al.  Fabrication of bulk glassy Zr55Al10Ni5Cu30 alloy of 30 mm in diameter by a suction casting method , 1996 .

[14]  W. Johnson,et al.  A highly processable metallic glass: Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 , 1993 .

[15]  Stephens,et al.  Structure of rapidly quenched Al-Mn. , 1985, Physical review letters.