Glass Forming Ability and Crystallization Behaviors of the Ti-Cu-Ni-(Sn) Alloys with Large Supercooled Liquid Region

2000 ◽  
Vol 644 ◽  
Author(s):  
Y.C. Kim ◽  
S. Yi ◽  
W.T. Kim ◽  
D.H. Kim

AbstractThe thermal stability and crystallization behavior of melt spun amorphous Ti50Cu35Ni15-xSnx (x=0, 3, 5, 7) alloys has been studied in by thermal analysis (DSC and DTA) and X-ray diffractometry. Partial replacement of Ni by Sn up to 5 at % in Ti50Cu35Ni15 alloy improved thermal stability and glass forming ability. The onset temperature of the first exotherm increased from 739 to 756 K with increasing Sn content x from 0 to 5, and then decreased to 745 K for the alloy with x=7 due to change in crystallization sequence. Melt spun amorphous Ti50Cu35Ni12Sn3 and Ti50Cu35Ni10Sn5 alloys exhibit ΔTx exceeding 78 and 76 K, respectively, which is significantly larger than ΔTx of 46 K in Ti50Cu35Ni15 alloy. Amorphous Ti50Cu35Ni15 alloy crystallized by precipitation of supersaturated cubic Ti(Ni,Cu) phase followed by decomposition into a mixture of TiCu and TiNi at higher temperature. Amorphous Ti50Cu35Ni15-xSnx (x=3, 5) phase crystallized by precipitation of cubic Ti(Ni,Cu) phase, followed by transformation into a mixture of TiNi, TiCu, Ti3Sn phases. Amorphous Ti50Cu32Ni8Sn7 phase crystallized by co- precipitation of cubic Ti(Ni,Cu) phase and unidentified phase, followed by transformation into a mixture of TiNi, TiCu, Ti3Sn phases.

Open Physics ◽  
2004 ◽  
Vol 2 (1) ◽  
Author(s):  
M. Shapaan ◽  
J. Lábár ◽  
L. Varga ◽  
J. Lendvai

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.


2015 ◽  
Vol 833 ◽  
pp. 79-84 ◽  
Author(s):  
Sheng Li Zhu ◽  
Guo Qiang Xie ◽  
Akihisa Inoue ◽  
Zhen Duo Cui ◽  
Xian Jin Yang ◽  
...  

We investigated the effects of addition elements (Sn, Al, Si, Ag, Fe, Cr) with a small amount on the glass-forming ability, thermal stability and mechanical properties of the Ti-Zr-Cu-Pd glassy alloy system. The results revealed that minor Sn addition improved the glass-forming ability, thermal stability and plasticity, Si addition enlarged the supercooled liquid region, and Fe addition improved the plasticity, while minor additions of Si, Ag, Fe, and Cr lowered the glass-forming ability, and Al and Cr additions were harmful to the plasticity of the Ti-Zr-Cu-Pd glassy alloy system.


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.


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.


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.


2010 ◽  
Vol 504 ◽  
pp. S132-S134 ◽  
Author(s):  
Qikui Man ◽  
Huaijun Sun ◽  
Yaqiang Dong ◽  
Baolong Shen ◽  
Hisamichi Kimura ◽  
...  

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.


2014 ◽  
Vol 670-671 ◽  
pp. 86-89
Author(s):  
Shi Wen He

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.


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