On the Effect of Al on the Formation of Amorphous Mg-Al-Cu-Y Alloys

1998 ◽  
Vol 554 ◽  
Author(s):  
M. Ohnuma ◽  
S. Linderoth ◽  
N. Pryds ◽  
M. Eldrup ◽  
A. S. Pedersen
Keyword(s):  
Glass Transition ◽  
Amorphous Alloys ◽  
Exothermic Peak ◽  
Bulk Amorphous Alloy ◽  
X Ray Diffraction ◽  
Glass Forming ◽  
Dsc Measurements ◽  
Clear Glass ◽  
Overlapping Peaks ◽  
Melting And Solidification

AbstractThe bulk amorphous alloy (Mg1-xAlx)60Cu30Y10 has been studied, in particular the influence of Al concentration on the glass forming ability and on the various transition temperatures. The amorphous single phase has been obtained for x up to 0.07 by casting into a wedge-shaped copper mold. The amorphous alloys were investigated by differential scannning calorimetry (DSC). All the specimens with x = 0 - 0.07 show a clear glass transition. The crystallization temperature decreases with increasing Al concentration, while the temperatures of the glass transition, melting and solidification change only slightly. The DSC measurements show that for Al contents below 0.05 the first exothermic peak which corresponds to crystallization, consists of two overlapping peaks. To clarify the origin of the splitting of the first exothermic peak, the crystallization process of Mg60Cu30Y10 alloy has also been studied by x-ray diffraction.

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 Crystallization Kinetics of Al-Mg-Ni-La Metallic Glasses

2014 ◽  
Vol 960-961 ◽  
pp. 161-164 ◽  
Author(s):  
Juan Mu ◽  
Hai Feng Zhang
Keyword(s):  
Crystallization Kinetics ◽  
Glass Forming Ability ◽  
Continuous Heating ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Glass Forming ◽  
Dsc Measurements ◽  
Mg Addition ◽  
Kinetics Of ◽  
Thermal Stability Of

Glass forming ability and crystallization kinetics of Al-Mg-Ni-La alloys have been investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The maximum thickness achievable in glasses of Al76Mg11Ni8La5and Al69Mg18Ni8La5ribbons were 200 and 120 μm, respectively. The crystallization temperature and peak temperature indicated by DSC measurements displayed dependence on the heating rate during continuous heating, and were coincident with Lanoka’s relationship. The activation energies for the crystallization reactionExwere obtained from the Kissinger’s equation. The results show the Mg addition is beneficial to the thermal stability of the amorphous phase.

Effect of Neodymium on the Glass-Forming Ability and Magnetic Properties of Fe-Based Bulk Amorphous Alloys

2015 ◽  
Vol 1120-1121 ◽  
pp. 440-445
Author(s):  
Hua Man
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Glass Forming Ability ◽  
High Thermal Stability ◽  
Bulk Amorphous Alloy ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Crystallization Peak ◽  
Bulk Amorphous Alloys ◽  
Glass Forming

The glass forming ability and magnetic properties were investigated for adding neodymium to the Fe71-xNb4B25Ndx (x=0, 3, 5, 7,10) alloys prepared by copper suction casting. It was found that proper neodymium (x=5~10 at.%) could improve glass forming ability of Fe-Nb-B alloys effectively. Bulk amorphous Fe66Nd5B25Nb4 and Fe64Nd7B25Nb4 samples were obtained and presented high thermal stability and good soft magnetic properties. The value of activation energy of the first crystallization peak for the bulk amorphous alloy Fe64Nd7B25Nb4 is 683 kJ/mol.

scholarly journals Structure and Soft Magnetic Properties of the Amorphous Alloys: Fe61Co10Ti3-xY6+xB20 (x = 0, 1)

2016 ◽  
Vol 61 (1) ◽  
pp. 445-450
Author(s):  
K. Błoch
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Major Effect ◽  
Exothermic Peak ◽  
Soft Magnetic Properties ◽  
X Ray Diffraction ◽  
Cast State ◽  
Soft Magnetic ◽  
Two Peaks ◽  
Thermal Stability Of

This paper presents studies relating to the structure, soft magnetic properties and thermal stability of the following bulk amorphous alloys: Fe61Co10Ti3-xY6+xB20 (x = 0, 1). On the basis of the performed X-ray diffraction studies and Mössbauer spectroscopy, it was found that investigated samples were amorphous in the as-cast state. The DSC curve obtained for Fe61Co10Ti2Y7B20 alloy exhibited one exothermic peak, while for the Fe61Co10Ti3Y6B20 sample, two peaks were distinguishable. The change in the chemical structure of the investigated alloys has a major effect on their soft magnetic properties; especially on coercivity and saturation magnetization. On the basis of the magnetization curves analysis, the spin wave stiffness parameter Dsp were determined for the investigated alloys.

Design of a bulk amorphous alloy containing Cu–Zr with simultaneous improvement in glass-forming ability and plasticity

2007 ◽  
Vol 22 (2) ◽  
pp. 486-492 ◽  
Author(s):  
Seok-Woo Lee ◽  
Sang-Chul Lee ◽  
Yu-Chan Kim ◽  
E. Fleury ◽  
Jae-Chul Lee
Keyword(s):  
Amorphous Alloy ◽  
Amorphous Alloys ◽  
Glass Forming Ability ◽  
Bulk Amorphous Alloy ◽  
Mixing Enthalpy ◽  
High Plasticity ◽  
Atomic Packing ◽  
Bulk Amorphous Alloys ◽  
Glass Forming ◽  
Enthalpy Difference

We synthesized bulk amorphous alloy systems of Cu43Zr43Al7X7 (X = Be, Ag; numbers indicate at.%), with the objective of simultaneously enhancing the glass-forming ability (GFA) and the plasticity. The alloys not only exhibit high plasticity (∼7%, ∼8%), but also possess enhanced GFA (alloys with 12 and 8 mm diameter). The possible mechanisms underlying this enhanced GFA and plasticity exhibited by these alloys are discussed based on the atomic-packing state and atomistic-scale compositional separation associated with the mixing enthalpy difference. A strategy for designing bulk amorphous alloys with simultaneous improvement in the GFA and the plasticity is proposed from the viewpoint of atomic-packing state and atomistic-scale phase separation.

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.

Phase Equilibria in the Zr-Cu-Al System: Implications for Bulk Metallic Glass Formation

1998 ◽  
Vol 554 ◽  
Author(s):  
S. A. Syed ◽  
D. Swenson
Keyword(s):  
Ternary Phase ◽  
Amorphous State ◽  
Bulk Amorphous Alloy ◽  
Alloy Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Forming ◽  
Equilibrium Relationships ◽  
Equilibrium Phases ◽  
Preliminary Phase

AbstractPreliminary phase equilibrium relationships have been established in the Zr-Cu-Al system at 800 °C, using a combination of X-ray diffraction and electron probe microanalysis. These results are similar to previous investigations that have been reported in the literature. Several ternary phases are found to exist in this system, many of which lie within the gross compositional vicinity of interest to bulk amorphous alloy formation. The equilibrium phases present in the alloy Zr65Cu27.5A17.5, which exhibits a particularly high Tx-Tg in the amorphous state, are Zr2Cu and minor amounts of two additional phases: Zr3Al and what may be a ternary phase with a composition near Zr6CuAl3. When the 800 °C phase diagram isotherm is correlated with the known glass forming composition range of the Zr-Cu-Al system, it is found that the best glass forming behavior is confined to those regions of the diagram in which all equilibria include Zr-Cu constituent binary phases and Al-poor ternary phases. This may suggest that difficulties in the nucleation of these binary phases plays a role in the glass forming ability of Zr-Cu-Al and related higher order alloys.

Structure, Annealing Characteristics and Mechanical Properties of Mg60Cu30-yY10Siy Bulk Amorphous Alloys

2002 ◽  
Vol 754 ◽  
Author(s):  
U. Wolff ◽  
B. Yang ◽  
N. Pryds ◽  
J.A. Wert
Keyword(s):  
Mechanical Properties ◽  
Amorphous Alloys ◽  
Simple Technique ◽  
Partial Substitution ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Glass Forming ◽  
Si Content ◽  
Constant Heating

ABSTRACTThe effect of different Si contents on the glass forming ability (GFA) and the amorphous-to-crystalline transformation has been investigated for the Mg-Cu-Y-Si system. Four Mg60Cu30-yY10Siy (y = 1–5 at.%) alloys were prepared using a relatively simple technique of rapid cooling of the melt in a copper mould. Crystallization was induced by heat treatment of the alloys and the samples were then characterized concerning their microstructure and thermal stability by X-ray diffraction (XRD), optical (OM) and scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) at a constant heating rate. Partial substitution of Cu by Si leads to a transition of the as-cast structure at a constant cooling rate from amorphous to crystalline with increasing Si content. Furthermore, the glass transition temperature (Tg) of the Mg-Cu-Y-Si alloy is lower compared to the Mg-Cu-Y system. The mechanical properties of the bulk Mg-Cu-Y-Si alloys have been investigated and found to vary with the Si content.

scholarly journals Synthesis of Bulk Amorphous Alloy from Fe-Base Powders by Explosive Consolidation

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 727 ◽  
Author(s):  
Jianbin Li ◽  
Ming Lu ◽  
Yongbao Ai ◽  
Cong Tao ◽  
Yun Xiong
Keyword(s):  
Glass Transition ◽  
Amorphous Alloy ◽  
Supercooled Liquid ◽  
Amorphous Structure ◽  
Bulk Amorphous Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Explosive Consolidation ◽  
Crystallization Onset ◽  
Thermal Stability Of

A Fe61Cr2Nb3Si12B22 amorphous alloy rod sample of 8.8 mm diameter has been successfully prepared through explosive consolidation. The structure and thermal stability of the as-synthesized sample have been analyzed through X-ray diffraction (XRD) and differential scanning calorimeter (DSC) analysis. The results demonstrate that the sample still retains an amorphous structure, and the glass transition temperature (Tg), the crystallization onset temperature (Tx), the supercooled liquid zone (ΔTx) (Tx − Tg) and the reduced glass transition temperatures (Trg) (Tg/Tm) are 784 K, 812 K, 28 K, and 0.556, respectively. Its microstructure has been investigated by optical microscopy (OM) and scanning electron microscopy (SEM). The average microhardness of the alumina compact is about 1069 HV.

Sign in / Sign up

Export Citation Format

Share Document