The influence of Nb and Zr on glass-formation ability in the ternary Fe–Nb–B and Fe–Zr–B and quaternary Fe–(Nb,Zr)–B alloy systems

2008 ◽  
Vol 23 (2) ◽  
pp. 392-401 ◽  
Author(s):  
J.H. Yao ◽  
H. Yang ◽  
J. Zhang ◽  
J.Q. Wang ◽  
Y. Li
Keyword(s):  
Microstructure Evolution ◽  
Glass Formation ◽  
Critical Size ◽  
Three Dimensional ◽  
Glass Forming Ability ◽  
Crystalline Phases ◽  
Glass Forming ◽  
Composition Space ◽  
Theoretical Predictions ◽  
Optimum Glass

Glass-forming ability (GFA) in relation to microstructure evolution in the ternary Fe–Nb–B and Fe–Zr–B and quaternary Fe–(Nb,Zr)–B systems was systematically studied in a three-dimensional composition space. Through navigating, it was revealed that alloys with the optimum glass-forming ability (GFA) are coupled with composition regions surrounded by competing crystalline phases. Alloys Fe71Nb6B23, Fe77Zr4B19, and Fe71(Nb0.8Zr0.2)6B23 were illustrated to be the best glass formers in the ternary Fe–Nb–B and Fe–Zr–B systems and the quaternary Fe–(Nb,Zr)–B system, respectively, with a critical size for amorphous formation up to 2 mm. They were compared with the theoretical predictions on the basis of an efficient dense-packing model, and good agreements were obtained.

Property of Cu-Zr-Ti Ternary Alloys

2010 ◽  
Vol 146-147 ◽  
pp. 1477-1481 ◽  
Author(s):  
An Hui Cai ◽  
Wei Ke An ◽  
Xiao Song Li ◽  
Yun Luo ◽  
Tie Lin Li
Keyword(s):  
Crystalline Phase ◽  
Glass Formation ◽  
Maximum Size ◽  
Glass Forming Ability ◽  
Ternary Alloys ◽  
Crystalline Phases ◽  
Atom Ratio ◽  
Glass Forming ◽  
Transformation Sequence

The influence of Zr on the property of Cu(50+x)Zr(40-x)Ti10 (0≤x≤30 at.%) alloys were investigated. The results show that the maximum size for the glass formation in this Cu-Zr-Ti system is less than 8 mm. The hardness increases with decreasing of the Zr content, then decreases when the Zr content exceeds 10~15 at.% due to the obvious alteration of the type of the crystalline phases and the microstructure. With decreasing of the Zr content, the transformation sequence of the main Cu-Zr phase is Cu10Zr7→Cu5Zr→Cu51Zr14; the transformation sequence of Cu-Ti phase is Cu4Ti3→CuTi→CuTi3. In addition, the atom ratio of Cu60Zr30Ti10 alloys is coherent with that of their corresponding crystalline phase, resulting in its better glass forming ability.

Effects of Addition of Al, Ti and Ag on Glass-Forming Ability of Cu50Zr50 Alloy

2007 ◽  
Vol 561-565 ◽  
pp. 1333-1336 ◽  
Author(s):  
Qing Sheng Zhang ◽  
Wei Zhang ◽  
Akihisa Inoue
Keyword(s):  
Thermal Stability ◽  
Glass Formation ◽  
Alloy Composition ◽  
Critical Diameter ◽  
Alloy System ◽  
Glass Forming Ability ◽  
Crystalline Phases ◽  
Simultaneous Addition ◽  
Glass Forming

The thermal stability and crystalline phases precipitated from the as-cast rods of the Cu50Zr50-based alloys with addition of Al or simultaneous addition of Al/Ti or Al/Ag elements were investigated using DSC, DTA and XRD. The value of Tx, Trg and γ as a function of alloy composition shows a same trend, in which the Cu46Zr46Al8 alloy exhibits the largest value of Tx, Trg and γ. However, this trend is different from the variation of the dc with alloy composition, in which the Cu42Zr42Al8Ag8 alloy has the largest dc for glass formation. Trg′ based on Tg/Tm has a good correlation with the critical diameter for glass formation in this alloy system. It was found that the alloy with higher GFA has more complex precipitated crystalline phases from the as-cast rod with a diameter larger than the critical diameter for glass formation.

Doubling the Critical Size for Bulk Metallic Glass Formation in the Mg–Cu–Y Ternary System

2005 ◽  
Vol 20 (9) ◽  
pp. 2252-2255 ◽  
Author(s):  
H. Ma ◽  
Q. Zheng ◽  
J. Xu ◽  
Y. Li ◽  
E. Ma
Keyword(s):  
Metallic Glass ◽  
Ternary System ◽  
Bulk Metallic Glass ◽  
Glass Formation ◽  
Composition Dependence ◽  
Critical Size ◽  
Glass Forming Ability ◽  
Glass Forming ◽  
Copper Mold Casting ◽  
Mold Casting

Mg−Cu−Y alloys with optimal glass forming ability have been found at off-eutectic compositions. The critical size for bulk metallic glass formation at the pinpointed compositions more than doubles that of the previously discovered eutectic Mg65Cu25Y10 alloy, leading to fully glassy rods with near-centimeter diameters in the ternary system upon copper mold casting. The result is a striking demonstration of the strong composition dependence of the glass forming ability, as well as of the need to scrutinize off-eutectic compositions. The implications of the discovery are discussed.

Glass Formation and Glass Forming Ability of Alloys Near Eutectic Composition

2000 ◽  
Vol 644 ◽  
Author(s):  
Y. Li
Keyword(s):  
Glass Transition ◽  
Glass Formation ◽  
Eutectic Composition ◽  
Glass Forming Ability ◽  
Critical Section ◽  
Bulk Glass ◽  
Melting Behaviour ◽  
Eutectic Alloys ◽  
Section Thickness ◽  
Glass Forming

AbstractOnset temperature, Tm and offset temperature (liquidus) Tl of melting of a series of bulk glass forming alloys based on La, Mg, and Pd have been measured by studying systematically the melting behaviour of these alloys using DTA or DSC. Bulk metallic glass formation has been found to be most effective at or near their eutectic points and less effective for off-eutectic alloys. Reduced glass transition temperature Trg given by Tg/Tl is found to show a stronger correlation with critical cooling rate or critical section thickness for glass formation than Trg given by Tg/Tm.

Formation of Bulk Metallic Glasses and Their Composites

MRS Bulletin ◽  
2007 ◽  
Vol 32 (8) ◽  
pp. 624-628 ◽  
Author(s):  
Y. Li ◽  
S. J. Poon ◽  
G. J. Shiflet ◽  
J. Xu ◽  
D. H. Kim ◽  
...  
Keyword(s):  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Glass Forming Ability ◽  
Glass Forming ◽  
Wide Range ◽  
Optimum Glass

AbstractA great expansion in the number of alloy compositions known to give bulk metallic glasses (BMGs) has occurred in recent years. This progress is reviewed, and factors contributing to glass-forming ability are discussed. Practical strategies for pinpointing compositions with optimum glass-forming ability are presented, with examples of their use. Consideration is also given to the wide range of possibilities for BMG-based composites.

Bulk glass formation in the Ni–Zr–Ti–Nb–Si–Sn alloy system

2004 ◽  
Vol 19 (8) ◽  
pp. 2221-2225 ◽  
Author(s):  
J.Y. Lee ◽  
D.H. Bae ◽  
J.K. Lee ◽  
D.H. Kim
Keyword(s):  
Glass Formation ◽  
Liquidus Temperature ◽  
Eutectic Composition ◽  
Composition Range ◽  
Alloy System ◽  
Glass Forming Ability ◽  
Maximum Diameter ◽  
Bulk Glass ◽  
Glass Forming ◽  
Crystallization Onset

In this study, the effect of addition of Nb on glass formation in Ni–Ti–Zr–Si–Sn alloys has been studied. The composition range for bulk glass formation with Dmax > 2 mm (Dmax, maximum diameter for glass formation by injection cast method) becomes wider when compared with the non-Nb–containing alloy. The ΔTx (= Tx – Tg; Tx, crystallization onset temperature; Tg, glass transition temperature), Trg (= Tg/Tl; Tl, liquidus temperature) and γ [= Tx/(Tl + Tg)] values for the alloys Dmax > 2 mm are in the range of 40–59, 0.638–0.651, and 0.410–0.419, respectively. The compositions of the alloys (Dmax > 2 mm) are closer to pseudo-eutectic composition than that of the alloy without Nb, showing an improved glass forming ability. The critical cooling rate for glass formation (Dmax = 5 mm) is estimated to be order of approximately 40 K/s.

Glass Forming Ability in Transition Metal Films at 1010 K/s

1983 ◽  
Vol 28 ◽  
Author(s):  
M. Von Allmen ◽  
K. Affolter
Keyword(s):  
Transition Metal ◽  
Kinetic Analysis ◽  
Glass Formation ◽  
Time Lag ◽  
Metal Films ◽  
Glass Forming Ability ◽  
Physical Parameters ◽  
Nucleation Time ◽  
Glass Forming

ABSTRACTGlass formation by ns and ps laser quenching is investigated for the systems Au-Ti, Co-Ti, Cr-Ti and Zr-Ti. Glassy phases are found in all but the last system. These results (as well as earlier ones) show little correlation with published rules to predict glass forming ability, but are consistent with the kinetic analysis presented. Simple Physical parameters related to glass forming ability are discussed. Comparison with results for Cr-Ti allows a determination of the nucleation time-lag.

Glass formation from low molecular weight organic melts

1995 ◽  
Vol 10 (8) ◽  
pp. 2128-2136 ◽  
Author(s):  
Seong-Jin Kim ◽  
T.E. Karis
Keyword(s):  
Molecular Structure ◽  
Molecular Weight ◽  
Hydrogen Bonding ◽  
Glass Formation ◽  
Glass Forming Ability ◽  
Rotational Isomerism ◽  
Molecular Structures ◽  
Low Molecular Weight ◽  
Glass Forming ◽  
Temperature Crystallization

Glass formation from the melt of organic monomers was studied for a variety of different organic molecular structures with Tg near ambient temperature. Crystallization is suppressed by one or more of the molecular properties, hydrogen bonding, interlocking, dipolar, and hydrogen bonding, combined with hindered rotational isomerism. Examples of materials in each category are presented for illustration. The viscosity of undercooled liquids was characterized by the Vogel-Tammon-Fulcher (VTF) equation, η = A cxp[DT0/(T - T0)], where A, D, and T0 are experimentally determined parameters. Our experimental D values are discussed in relation to the molecular structure and glass formation mechanism. The insight provided by our interpretation is intended to assist in the design of new molecular structures with controlled viscosity-temperature characteristics, as well as glass-forming ability by cooling from melts.

Bulk Glass Formation in an Fe-Based Fe–Y–Zr–M (M = Cr, Co, Al)–Mo–B System

2004 ◽  
Vol 19 (3) ◽  
pp. 921-929 ◽  
Author(s):  
Z.P. Lu ◽  
C.T. Liu ◽  
C.A. Carmichael ◽  
W.D. Porter ◽  
S.C. Deevi
Keyword(s):  
Metallic Glasses ◽  
Glass Formation ◽  
Amorphous Alloys ◽  
High Strength ◽  
Supercooled Liquid ◽  
Glass Forming Ability ◽  
Bulk Glass ◽  
Bulk Amorphous Alloys ◽  
Glass Forming ◽  
Hardness Values

Several new bulk metallic glasses based on Fe–Y–Zr–(Co, Cr, Al)–Mo–B, which have a glass-forming ability superior to the best composition Fe61Zr10Co7Mo5W2B15 reported recently, have been successfully developed. The as-cast bulk amorphous alloys showed a distinctly high thermal stability with glass-transition temperatures above 900 K, supercooled liquid regions above 60 K, and high strength with Vickers hardness values larger than HV 1200. The suppression of the growth of primary phases in the molten liquids and the resultant low liquidus temperatures were found to be responsible for the superior glass-forming ability in these new alloys. It was found that the addition of 2% Y not only facilitated bulk glass formation, but the neutralizing effect of Y with oxygen in the molten liquids also improved the manufacturability of these amorphous alloys.

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