Viscosity of Mechanically Alloyed Amorphous Zr-Cu-Al-Ni Matrix Composites in the Supercooled Liquid Region

2002 ◽  
Vol 13 ◽  
pp. 71-76
Author(s):  
Stefano Deledda ◽  
Jürgen Eckert ◽  
Ludwig Schultz
Keyword(s):  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Matrix Composites ◽  
Mechanically Alloyed

scholarly journals Mechanically Alloyed Amorphous Ti50(Cu0.45Ni0.55)44–xAlxSi4B2 Alloys with Supercooled Liquid Region

2002 ◽  
Vol 17 (7) ◽  
pp. 1743-1749 ◽  
Author(s):  
L. C. Zhang ◽  
J. Xu ◽  
E. Ma
Keyword(s):  
Amorphous Alloys ◽  
Supercooled Liquid ◽  
High Energy ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Mechanically Alloyed ◽  
Scanning Calorimetry ◽  
Beneficial Effects ◽  
State Process ◽  
Transmission Electron

A high-energy ball milling procedure has been developed to produce amorphous alloys in Ti50(Cu0.45Ni0.55)44−xAlxSi4B2 (x= 0, 4, 8, 12) powder mixtures. The milling products were characterized using x-ray diffraction, differential scanning calorimetry, and transmission electron microscopy. The Ti-based amorphous alloy powders prepared through this solid-state process exhibit a well-defined glass transition and a supercooled liquid region (ΔTx =64 K) close to the largest achieved so far for Ti-based undercooled melts. The substitution of Al for Cu and Ni has beneficial effects on stabilizing the supercooled liquid. Residual nanocrystals of the αTi structure are uniformly dispersed in the amorphous matrix. The composite alloy powders offer the potential for consolidation in the supercooled liquid region to bulk lightweight amorphous alloys and the possibility to attain desirable mechanical properties.

Formation of Amorphous and Nanocrystalline Phases in Mechanically Alloyed Zr-, Al-, and Mg-Base Transition Metal Alloys

1994 ◽  
Vol 362 ◽  
Author(s):  
M. Seidel ◽  
J. Eckert ◽  
H.-D. Bauer ◽  
L. Schultz
Keyword(s):  
Transition Metal ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Metal Alloys ◽  
Liquid Region ◽  
Mechanically Alloyed ◽  
Scanning Calorimetry ◽  
Transition Metal Alloys ◽  
Base Transition ◽  
Nanocrystalline Phases

AbstractZr-, Al-, and Mg-base transition metal alloys have been prepared by mechanical alloying and investigated by x-ray diffraction, differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). Amorphous phases with significant supercooled liquid region form directly during milling from the crystalline starting materials for Zr- and Mg-base alloys. For Albase alloys the formation of mixtures of amorphous and nanocrystalline phases is observed. The results are compared with data for melt-spun and quenched materials. Possible mechanisms for glass formation and crystallization are discussed.

Formation of Ni57Zr20Ti22Pb1 Amorphous Powders by Mechanical Alloying

2007 ◽  
Vol 539-543 ◽  
pp. 2767-2772
Author(s):  
Pee Yew Lee ◽  
S.S. Hung ◽  
Jason S.C. Jang ◽  
Giin Shan Chen
Keyword(s):  
Thermal Stability ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Atomic Size ◽  
X Ray ◽  
Amorphous Powders ◽  
Thermal Stability Of

In the current study, the amorphization behavior of mechanically alloyed Ni57Zr20Ti22Pb1 powder was examined in details. The conventional X-ray diffraction results confirm that the fully amorphous powders formed after 5 hours of milling. The thermal stability of the Ni57Zr20Ti22Pb1 amorphous powders was investigated by differential scanning calorimeter (DSC). As the results demonstrated, the glass transition temperature (Tg) and the crystallization temperature (Tx) are 760 K and 850 K, respectively. The supercooled liquid region is 90 K. The appearance of wide supercooled liquid region may be mainly due to the Pb additions which cause the increasing differences in atomic size of mechanically alloyed Ni57Zr20Ti22Pb1 powders.

Amorphization and thermal stability of mechanically alloyed Zr54Cu19Ni8Al8Si5Ti5O1

2005 ◽  
Vol 903 ◽  
Author(s):  
Vassilios Kapaklis ◽  
Athanasios Georgiopoulos ◽  
Peter Schweiss ◽  
Constantin Politis
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Supercooled Liquid ◽  
High Energy ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Mechanically Alloyed ◽  
Scanning Calorimetry ◽  
Arc Melting ◽  
Thermal Stability Of

AbstractIn the present work we have intentionally introduced significant amount of oxygen to Zr- based alloys. Samples were prepared either by high energy ball milling of the elemental powders and single phase α-ZrO0.43 at the appropriate stoichiometry, or by melting in an Zr-gettered arc melting facility, in both cases under purified argon atmosphere. The effect of small amounts of oxygen (∼1 at. %) on the amorphization process and the thermal stability of mechanically alloyed Zr54Cu19Ni8Al8Si5Ti5O1 powders and arc melted bulk samples was studied by X-ray diffraction and differential scanning calorimetry. It was found that the introduction of oxygen to the alloy composition does not inhibit the amorphization but enhances greatly the thermal stability of the mechanically alloyed amorphous powders. Compared to samples without oxygen prepared either by arc melting or mechanical alloying, samples with oxygen show an increase of the supercooled liquid region from ΔTx−g=Tx−Tg=117 °C to 141 °C where Tx is the crystallization and Tg the glass transition temperature. The glass transition for the mechanically alloyed samples (Tgma) remains unaffected at 336 °C.

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