Comments on “Fabrication of ternary Mg–Cu–Gd bulk metallic glass with high glass-forming ability under air atmosphere” [H. Men and D.H. Kim, J. Mater. Res. 18, 1502 (2003)]

2004 ◽  
Vol 19 (2) ◽  
pp. 427-428 ◽  
Author(s):  
Z.P. Lu ◽  
C.T. Liu
Keyword(s):  
Glass Transition ◽  
Metallic Glasses ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Bulk Amorphous Alloy ◽  
Liquid Region ◽  
Glass Forming ◽  
Air Atmosphere ◽  
Acta Mater

A new Mg-based bulk amorphous alloy (i.e., Mg65Cu25Gd10) has successfully been developed by Men and Kim [H. Men and D.H. Kim, J. Mater. Res. 18, 1502 (2003)]. They showed that this alloy exhibits significantly improved glass-forming ability (GFA) in comparison with Mg65Cu25Y10 alloy. However, this improved GFA cannot be indicated by the supercooled liquid region ΔT and the reduced glass-transition temperature Trg. As shown in the current comment, the new parameter γ, Tx/(Tg + Tl) defined in our recent papers [Z.P. Lu and C.T. Liu, Acta Mater. 50, 3501 (2002); Z.P. Lu and C.T. Liu, Phys. Rev. Lett. 91, 115505 (2003)] can well gauge GFA for bulk metallic glasses, including the current Mg-based alloys.

GLASS FORMING ABILITY AND KINETIC CHARACTERS OF PARAMAGNETIC Nd60Co40-xAlx(x=5, 10, 15) BULK METALLIC GLASSES

2004 ◽  
Vol 18 (14) ◽  
pp. 679-685 ◽  
Author(s):  
L. XIA ◽  
Y. D. DONG
Keyword(s):  
Glass Transition ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Ternary Alloys ◽  
Liquid Region ◽  
Scanning Calorimetry ◽  
Glass Forming

Paramagnetic Nd 60 Co 40-x Al x(x=5, 10, 15) bulk metallic glasses (BMGs) were prepared in the shape of rods 2 mm in diameter by suction casting. The ternary alloys have shown distinct glass transitions in Differential Scanning Calorimetry (DSC) measurements and excellent glass-forming ability. The glass transition and crystallization behaviors as well as their kinetics have been studied. The reduced glass transition temperature and the supercooled liquid region of the alloys were found to increase with the increasing content of Al . The role of Al was discussed. The parameter γ defined by Liu et al. was employed to discuss the glass-forming ability of the alloys and the critical cooling rates as well as the critical section thickness of the alloys were predicted accordingly.

Critical Cooling Rate of Y36Nd20Al24Co20 Bulk Amorphous Alloy

2014 ◽  
Vol 670-671 ◽  
pp. 86-89
Author(s):  
Shi Wen He
Keyword(s):  
Glass Transition ◽  
Amorphous Alloy ◽  
Cooling Rate ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Bulk Amorphous Alloy ◽  
Liquid Region ◽  
Critical Cooling Rate ◽  
Glass Forming

A new bulk amorphous alloy, Y36Nd20Al24Co20, with a diameter of 5 mm was successfully fabricated by the method of equiatomic substitution for the Y element in Y56Al24Co20amorphous alloy. The values of the supercooled liquid region ∆Tx(=Tx-Tg), the reduced glass transition temperature Trg(=Tg/Tl) and the parameter γ (=Tx/(Tg+Tl)) for Y36Nd20Al24Co20bulk amorphous alloy are 60K, 0.605 and 0.415, respectively. The critical cooling rate of the Y36Nd20Al24Co20bulk amorphous alloy was determined to be 40 K/s, providing an indication that this alloy has a high glass-forming ability.

Glass-Forming Ability and Mechanical Properties of Zr-Ni-Al Bulk Metallic Glasses with High Zr Content

2013 ◽  
Vol 750 ◽  
pp. 306-310
Author(s):  
Yan Hui Li ◽  
Wei Zhang ◽  
Chuang Dong ◽  
Akihiro Makino
Keyword(s):  
Mechanical Properties ◽  
Metallic Glasses ◽  
Critical Diameter ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Metallic Alloys ◽  
Liquid Region ◽  
Glass Forming ◽  
Alloy Series

The thermal stability and glass-forming ability (GFA) of Zr70Ni30−xAlx (x = 5 − 19) metallic alloys were investigated. Alloy with x = 8 has the largest critical diameter (dc) of 2 mm in the alloy series, which possesses the largest supercooled liquid region, Trg and γ value, simultaneously. Further addition of 2 − 4 at.% Nb to Zr70Ni22Al8 alloy by replacement of Zr increases the dc up to 6 mm. In addition, Zr70Ni22Al8 bulk metallic glass exhibits large compressive plastic strain of 13.8% with yielding stress of 1547 MPa and Young’s modulus of 79 GPa. Addition of Nb increases the strength but lowers the plasticity.

FORMATION OF La-Al-Ni-Cu-Fe BULK METALLIC GLASSES WITH HIGH GLASS-FORMING ABILITY

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2314-2319
Author(s):  
YUNFEI JI ◽  
SHUJIE PANG ◽  
CHAOLI MA ◽  
TAO ZHANG
Keyword(s):  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Main Element ◽  
Heat Of Mixing ◽  
Liquid Region ◽  
Glass Forming ◽  
Cu Alloy

The effect of alloy composition on improving glass-forming ability of La -based alloys is investigated in this work. Previous composition criteria demonstrated that the alloys with high glass-forming ability should have negative heats of mixing among the main constituent elements. In this study, the addition of Fe to a La -based La - Al - Ni - Cu alloy significantly improved the glass-forming ability, although the heat of mixing between Fe and the main element La is positive. La - Al - Ni - Cu - Fe bulk metallic glasses with diameters up to 15 mm were prepared by the method of pouring the molten alloys into a copper mold. These La - Al - Ni - Cu - Fe bulk metallic glasses exhibit relatively wide supercooled liquid region of about 50 k, and high T rg (T g /T l ) and γ(T x /(T g +T l )) values. It is found that the addition of Fe to the La - Al - Ni - Cu alloy lowers the Gibbs free energy difference between the liquid and crystalline phases in the supercooled liquid region and enhances the glass-forming ability of the alloy.

scholarly journals Crystallization Behavior of Al70Fe12.5V12.5Nb5 Amorphous Alloy Formed by Mechanical Alloying

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 383 ◽  
Author(s):  
Xuan Liu ◽  
Xingfu Wang ◽  
Yongli Si ◽  
Xiaokang Zhong ◽  
Fusheng Han
Keyword(s):  
Amorphous Alloy ◽  
Mechanical Alloying ◽  
Amorphous Alloys ◽  
Crystallization Behavior ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Liquid Region ◽  
Application Field ◽  
Glass Forming

In this study, the formation and crystallization of the Al70Fe12.5V12.5Nb5 amorphous alloys has been investigated. The addition of Nb enhances the supercooled liquid region and glass forming ability of the Al-Fe-V amorphous alloys. The Al70Fe12.5V12.5Nb5 amorphous alloy exhibits two distinct crystallization steps and a large supercooled liquid region at more than 100 K. Kissinger and Ozawa analyses showed that the two activation energies for crystallization (Ex) were estimated to be 366.3 ± 23.9 and 380.5 ± 23.9 kJ/mol. Large supercooled liquid regions are expected to gain an application field of Al-based amorphous alloys.

Magnetic Properties and Glass Forming Ability of Fe-B-Y-Nb-Zr Bulk Metallic Glasses

2012 ◽  
Vol 577 ◽  
pp. 27-30 ◽  
Author(s):  
San Xin Wang ◽  
Ze Yu Wu
Keyword(s):  
Thermal Stability ◽  
Magnetic Properties ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Maximum Diameter ◽  
Liquid Region ◽  
Casting Technique ◽  
Glass Forming

Bulk metallic glasses (BMGs) alloys (Fe71.2B24Y4.8)96Nb4-xZrx (x = 1-4 at.%) with a maximum diameter of 5 mm were synthesized with low purity materials by copper mold casting technique. The effect of Zr substitution for Nb on the structure, thermal stability and the magnetic properties has been studied. It was found that the substitution of an appropriate amount of Zr for Nb can improve the glass forming ability. The wide supercooled liquid region ∆Tx (exceeding 123 K) and a high Tg (exceeding 868 K) demonstrated a high thermal stability of the present Fe-based BMGs. In addition, these BMGs also exhibit good soft magnetic properties with relatively high saturation magnetization of 88 emu/g, and low coercivity of 20 Oe.

Glass-forming ability and magnetic properties of CoFeMoYB bulk glassy alloys with large supercooled liquid region

2010 ◽  
Vol 504 ◽  
pp. S132-S134 ◽  
Author(s):  
Qikui Man ◽  
Huaijun Sun ◽  
Yaqiang Dong ◽  
Baolong Shen ◽  
Hisamichi Kimura ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Liquid Region ◽  
Glass Forming ◽  
Glassy Alloys

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.

Sign in / Sign up

Export Citation Format

Share Document