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

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.

2004 ◽  
Vol 18 (14) ◽  
pp. 679-685 ◽  
Author(s):  
L. XIA ◽  
Y. D. DONG

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.


2004 ◽  
Vol 19 (2) ◽  
pp. 427-428 ◽  
Author(s):  
Z.P. Lu ◽  
C.T. Liu

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.


2012 ◽  
Vol 577 ◽  
pp. 27-30 ◽  
Author(s):  
San Xin Wang ◽  
Ze Yu Wu

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.


2007 ◽  
Vol 22 (6) ◽  
pp. 1710-1717 ◽  
Author(s):  
C.L. Qin ◽  
W. Zhang ◽  
K. Asami ◽  
H. Kimura ◽  
A. Inoue

Bulk metallic glasses (BMGs) with critical diameters of 2.5–3 mm were synthesized in the (Cu0.6Zr0.3Ti0.1)100−x−yNiyNbxsystem by copper-mold casting. These alloys exhibit a large supercooled liquid region (ΔTx) of 40–60 K and a high reduced glass transition temperature (Tg/Tl) of 0.60–0.61, indicating high glass-forming ability and high thermal stability of the supercooled liquid. The corrosion rates in 1 N HCl and 3 mass% NaCl solutions significantly decrease by simultaneous alloying with Ni and Nb elements. The addition is also effective in raising the pitting potential in chloride solutions. The addition of Ni and Nb is favorable for the alloys in forming Zr-, Ti-, and Nb-enriched highly protective surface films in HCl and NaCl solutions.


2013 ◽  
Vol 750 ◽  
pp. 306-310
Author(s):  
Yan Hui Li ◽  
Wei Zhang ◽  
Chuang Dong ◽  
Akihiro Makino

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.


Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 767
Author(s):  
Xianfeng Zhang ◽  
Xiao Cui ◽  
Zhuotong Du ◽  
Fangqiu Zu ◽  
Jinjing Li ◽  
...  

The internal friction (IF) behaviors of a series of LaCe-, Zr-, and La-based bulk metallic glasses (BMGs) were studied by a computer-controlled, conventional inverted torsion pendulum. The results indicate that with an increasing temperature, the IF also increases gradually in the supercooled liquid region, followed by a decrease caused by crystallization. BMGs with a good glass forming ability (GFA) usually possess a high IF peak value for an alloy system with the same constituent elements. Furthermore, the magnitude of the IF value (Qi−1) of the inflection point is an efficient criterion of GFA. The Qi−1 value is a valid criterion under the conditions of identical constituent elements and different element contents. However, Qi−1 and GFA have no relationship among different alloy systems.


2008 ◽  
Vol 498 (1-2) ◽  
pp. 464-467 ◽  
Author(s):  
K.Q. Qiu ◽  
J. Pang ◽  
Y.L. Ren ◽  
H.B. Zhang ◽  
C.L. Ma ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 383 ◽  
Author(s):  
Xuan Liu ◽  
Xingfu Wang ◽  
Yongli Si ◽  
Xiaokang Zhong ◽  
Fusheng Han

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.


Sign in / Sign up

Export Citation Format

Share Document