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 Behavior of Ni57Zr20Ti22Ge1 Powders by Mechanical Alloying

2011 ◽  
Vol 479 ◽  
pp. 48-53
Author(s):  
Kai Chen Kuo ◽  
Pee Yew Lee ◽  
Jai Yush Yen
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 Ni57Zr20Ti22Ge1 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 Ni57Zr20Ti22Ge1 amorphous powders was investigated by differential scanning calorimeter (DSC). As the results demonstrated, the glass transition temperature (Tg) and the crystallization temperature (Tx) are 761 K and 839 K, respectively. The supercooled liquid region ΔT is 78 K. The appearance of wide supercooled liquid region may be mainly due to the Ge additions which cause the increasing differences in atomic size of mechanically alloyed Ni57Zr20Ti22Ge1 powders.

Glass Forming Ability in Amorphous Ti50Cu35-xNi15Snx Alloys Prepared by Mechanical Alloying

2005 ◽  
Vol 475-479 ◽  
pp. 3451-3458 ◽  
Author(s):  
Chung Kwei Lin ◽  
C.C. Hsu ◽  
R.R. Jeng ◽  
Y.L. Lin ◽  
C.H. Yeh ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Differential Scanning Calorimeter ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Forming ◽  
Amorphous Powders ◽  
X Ray Absorption

in the present study, amorphous ti50cu35-xni15snx (x=0~7) alloy powders were synthesized by mechanical alloying technique. the amorphization behavior of ti50cu28ni15sn7 alloy powders was examined in details by scanning electron microscopy, differential scanning calorimeter, x-ray diffraction, and synchrotron x-ray absorption spectroscopy. the results show that fully amorphous powders formed after 7 hours of milling. The thermal stability of the Ti50Cu35-xNi15Snx amorphous powders was investigated by differential scanning calorimeter. The amorphous Ti50Cu35Ni15 powders (i.e., x=0) exhibit no glass transition behavior. However, the amorphous Ti50Cu35-xNi15Snx (x=3~7) powders were found to exhibit a supercooled liquid region before crystallization. Amorphous Ti50Cu28Ni15Sn7 alloy powders exhibits a wide supercooled liquid region of 61 K.

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.

Mechanical Alloying for Preparation of Ti50Fe45Sn5 Amorphous Alloys Powder

2011 ◽  
Vol 480-481 ◽  
pp. 104-108
Author(s):  
Ge Wang ◽  
Chun Zhang ◽  
Yu Ying Zhu ◽  
Zhi Gang Chao ◽  
Qiang Li
Keyword(s):  
Mechanical Alloying ◽  
Amorphous Alloys ◽  
Weight Ratio ◽  
Supercooled Liquid ◽  
High Energy ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Typical Morphology ◽  
Amorphous Powders

Ti50Fe45Sn5 amorphous alloys powder was prepared by mechanical alloying (MA) in a high-energy planetary ball mill. The non-crystallization degree was tested by X-ray diffraction (XRD). It was shown from the XRD results that a higher ball to powder weight ratio (BPR) is advantageous in preparing amorphous alloys powder. The microstructure and shape of the powder was observed by scanning electron microscope (SEM). It was shown from the SEM results that the as-milled amorphous alloys powder is flake shape and assembles together to be agglomeration structure, which is a typical morphology of amorphous powders prepared by MA. Thermodynamic properties and crystallization kinetics behavior of the as-milled amorphous alloys powder were measured by differential scanning calorimeter (DSC). The supercooled liquid region △Tx is broad (up to 119K) and the reduction glass transforming temperature Trg (0.78) is great, which shows that the as-milled amorphous alloys powder has a strong glass-forming ability and the thermal stability of the powder is excellent.

Glass-forming ability and thermal stability of Fe62Nb8−xZrxB30 and Fe72Zr8B20 amorphous alloys?

Open Physics ◽  
2004 ◽  
Vol 2 (1) ◽  
Author(s):  
M. Shapaan ◽  
J. Lábár ◽  
L. Varga ◽  
J. Lendvai
Keyword(s):  
Thermal Stability ◽  
Amorphous Alloys ◽  
Strong Dependence ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Partial Replacement ◽  
Liquid Region ◽  
Glass Forming ◽  
Thermal Stability Of

AbstractGlass-forming ability (GFA) and thermal stability of Fe62Nb8B30, Fe62Nb6Zr2B30 and Fe72Zr8B20 at % amorphous alloys were investigated by calorimetric (DSC and DTA) measurements. The crystallization kinetics was studied by DSC in the mode of continuous versus linear heating and it was found that both the glass transition temperature, Tg, and the crystallization peak temperature, Tp, display strong dependence on the heating rate. The partial replacement of Nb by Zr leads to lower Tg and Tx temperatures and causes a decrease of the supercooled liquid region. JMA analysis of isothermal transformation data measured between Tg and Tx suggests that the crystallization of the Fe62Nb8B30 and Fe62Nb6Zr2B30 amorphous alloys take place by three-dimensional growth with constant nucleation rate. Nb enhances the precipitation of the metastable Fe23B6 phase and stabilizes it up to the third crystallization stage. Zr addition increases the lattice constant of Fe23B6 and, at the same time, decreases the grain size.

Structural Study of Fe-Based Glassy Alloys with a Large Supercooled Liquid Region

2000 ◽  
Vol 644 ◽  
Author(s):  
M. Imafuku ◽  
S. Sato ◽  
T. Nakamura ◽  
H. Koshiba ◽  
E. Matsubara ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Random Network ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Size Mismatch ◽  
Atomic Structures ◽  
Glassy Alloys ◽  
The Difference

AbstractThe thermal stability and local atomic structures of glassy Fe70M10B20 (M = Hf, Zr, Nb, W and Cr) alloys were analyzed by DSC, ordinary X-ray diffraction and AXS measurements. The random network of the trigonal prism-like structure of (Fe,M)3B with edge-sharing, was identified in all the Fe70M10B20 (M = Hf, Zr, Nb, W and Cr) alloys in spite of the wide variety of thermal stability upon heating. Several unique primary precipitated crystalline phases, such as Fe23B6 type and Fe-M phases, were observed in the alloys exhibiting a high thermal stability. These crystallization reactions require relatively long range rearrangements of the constituents and hence the thermal stability of the glassy phase increases, leading to the appearance of a large supercooled liquid region upon heating. These phenomena may be originated from the difference in the chemical affinity and the atomic size mismatch between M and Fe or B.

Crystallization of Cu60Ti20Zr20 metallic glass with and without pressure

2003 ◽  
Vol 18 (4) ◽  
pp. 895-898 ◽  
Author(s):  
J. Z. Jiang ◽  
B. Yang ◽  
K. Saksl ◽  
H. Franz ◽  
N. Pryds
Keyword(s):  
Metallic Glass ◽  
Crystalline Phase ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Lattice Parameters ◽  
Type Structure ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Residual Amorphous Phase

Structural stability of a Cu60Ti20Zr20 metallic glass under pressure up to 4.5 GPa was investigated by x-ray diffraction. The sample exhibited a supercooled liquid region of 33 K and a ratio of the glass-transition temperature to the liquidus temperature of 0.63. The glass crystallized in two-step transformation processes in the pressure range of 0–4.5 GPa; the first was a primary reaction to form a Cu51Zr14-type structure crystalline phase with a spacing group P6/m (175) and lattice parameters a=11.235 Å and c=8.271 Å, and then the residual amorphous phase crystallized into a MgZn2-type structure crystalline phase with a spacing group P63/mmc (194) and lattice parameters a=5.105 Å and c=8.231 Å. Both crystallization temperatures increased with pressure having a slope of 19 K/GPa. The increase of the first crystallization temperature with increasing pressure in the glass can be explained by the suppression of atomic mobility. No significant structural change was detected in the Cu60Ti20Zr20 glass annealed in vacuum at 697 K for 1 h as compared to the as-prepared sample from x-ray diffraction measurements.

scholarly journals Structural and Phase Evolution upon Annealing of Fe76Si9−xB10P5Mox (x = 0, 1, 2 and 3) Alloys

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 881
Author(s):  
Darling Perea ◽  
Carolina Parra ◽  
Parthiban Ramasamy ◽  
Mihai Stoica ◽  
Jürgen Eckert ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Amorphous Alloys ◽  
Structural Evolution ◽  
Supercooled Liquid ◽  
Phase Evolution ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Glass Forming ◽  
Different Temperatures ◽  
Thermal Stability Of

Alloying elements play an important role in adjusting the magnetic and thermal properties of Fe-based amorphous alloys. In this work, the effect of Mo addition on the thermal stability, structural evolution, and magnetic properties of Fe76Si9B10P5 metallic glass was studied. The study revealed that the substitution of a small amount of Mo (1 at.%) for Si enhances the glass-forming ability (GFA) but reduces the thermal stability of the alloy, causing a reduction of the supercooled liquid region. Substitution of up to 3 at.% Mo for Si lowers the Curie temperature from 677 to 550 K and the saturation magnetization drops from 160 to 138 Am2/kg. The structural evolution was evaluated by annealing the glassy samples at different temperatures, revealing that the crystallization proceeds in multiple steps, beginning with the formation of different iron borides (FeB, Fe2B, FeB2 and Fe23B6) followed by transformation to a mixture of more stable phases.

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