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.

The Crystallization Research on the Zr-Based Bulk Metallic Glasses by Ion Thinning

2014 ◽  
Vol 887-888 ◽  
pp. 116-120
Author(s):  
Ying Liang Bai ◽  
Lian Long He
Keyword(s):  
Electron Microscope ◽  
Amorphous Alloy ◽  
Transmission Electron Microscope ◽  
Metallic Glasses ◽  
Bulk Amorphous Alloy ◽  
Edge Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Nickel Crystals

Transmission Electron Microscope (TEM) and X-Ray Diffraction (XRD) were used to investigate crystallization of the Zr70Cu8Ti7Ni15 bulk amorphous alloy, the results show that the edge region of BMGs sample produces nanosize Nickel crystals using the method of the ion thinning to make the TEM sample. The quantity of nanocrystals is proportional to the time of ion thinning and they are not residual crystals in the BMGs.

Formation of Ni57Zr20Ti22Pb1 Amorphous Powders by Mechanical Alloying

2007 ◽  
Vol 539-543 ◽  
pp. 2767-2772
Author(s):  
Pee Yew Lee ◽  
S.S. Hung ◽  
Jason S.C. Jang ◽  
Giin Shan Chen
Keyword(s):  
Thermal Stability ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Atomic Size ◽  
X Ray ◽  
Amorphous Powders ◽  
Thermal Stability Of

In the current study, the amorphization behavior of mechanically alloyed Ni57Zr20Ti22Pb1 powder was examined in details. The conventional X-ray diffraction results confirm that the fully amorphous powders formed after 5 hours of milling. The thermal stability of the Ni57Zr20Ti22Pb1 amorphous powders was investigated by differential scanning calorimeter (DSC). As the results demonstrated, the glass transition temperature (Tg) and the crystallization temperature (Tx) are 760 K and 850 K, respectively. The supercooled liquid region is 90 K. The appearance of wide supercooled liquid region may be mainly due to the Pb additions which cause the increasing differences in atomic size of mechanically alloyed Ni57Zr20Ti22Pb1 powders.

Isothermal Crystallization of Zr55Al10Ni5Cu30 Bulk Amorphous Alloy Near the Glass Transition Temperature

2004 ◽  
Vol 449-452 ◽  
pp. 933-936 ◽  
Author(s):  
Zhuang Qi Hu ◽  
Q.S. Zhang ◽  
Hai Feng Zhang ◽  
B.Z. Ding ◽  
Z.M. Rao
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Amorphous Alloy ◽  
Amorphous Phase ◽  
Isothermal Crystallization ◽  
Metastable Phases ◽  
Bulk Amorphous Alloy ◽  
Thermal Stability Of

Isothermal crystallization of Zr55Al10Ni5Cu30bulk amorphous alloy near the glass transition temperature has been investigated. The microstructures and thermal stability of the annealed amorphous alloy were examined by HRTEM, XRD and DSC. The amorphous phase in the Zr55Al10Ni5Cu30bulk amorphous alloy crystallized at 420°C through the following processes of amorphous →amorphous with clusters + metastable phases→metastable phases.

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.

scholarly journals The Influence of Annealing Temperature on Microstructure and Magnetic Properties of Fe74Co3Si8B10Al1Nb4 Amorphous Alloy Ribbons

2017 ◽  
Vol 2 (1) ◽  
pp. 44-47
Author(s):  
Shih Fan Chen ◽  
Chih Yuan Chen ◽  
Chien Fan Chiang
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloy ◽  
Coercive Force ◽  
Saturation Magnetization ◽  
Melt Spinning ◽  
Annealing Temperature ◽  
Supercooled Liquid ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry

Multi-component alloy ribbons with a composition of Fe74Co3Si8B10Al1Nb4 were prepared by a single roller melt-spinning method. The alloy had a fully amorphous structure, as determined by X-ray diffraction. The alloy ribbons were annealed for 10 min at temperatures of 350, 400, 450, 500, 550 and 600 oC, respectively. Differential scanning calorimetry curves indicated that the glass transition temperature (Tg) and the supercooled liquid range (ΔTx) of the amorphous alloy ribbon were about 494 oC and 43 oC, respectively. The ribbons showed soft magnetic properties, with a Curie temperature (Tc) at 284 oC, high saturation magnetization (Ms) of 1.18 T, and coercive force (Hc) of 33.66 A/m. In the present study, both saturation magnetization and coercive force of amorphous alloy ribbons increased with increasing the annealing temperature, due to precipitations and growth of α–Fe phase nanocrystals in the amorphous matrix. On the other hand, it was found that the coercive force of alloy ribbons reduced as a consequence of precipitations of Nb3Si phase if the annealing temperature reached 600 oC.

scholarly journals Determination of critical points of amorphous Fe – Si – Nb – Cu – Mo – B alloy using non-ambient X-Ray diffraction method

2019 ◽  
Vol 62 (6) ◽  
pp. 492-493
Author(s):  
N. N. Nikul’chenkov ◽  
A. S. Yurovskikh ◽  
M. L. Lobanov
Keyword(s):  
Amorphous Alloy ◽  
Critical Points ◽  
Diffraction Method ◽  
Casting Process ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Nanocrystalline State ◽  
X Ray ◽  
Planar Flow Casting

Critical points of amorphous alloy of Fe – Si – Nb – Cu – Mo – B system was determined using the non-ambient x-ray diffraction method. The sample with amorphous structure was produced by planar flow casting process. Temperature range of alloy nanocrystalline state was established

Superconducting characteristics and the thermal stability of tungsten-based amorphous thin films

1992 ◽  
Vol 7 (4) ◽  
pp. 853-860 ◽  
Author(s):  
Seiichi Kondo
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Electrical Resistivity ◽  
Amorphous Alloy ◽  
Diffraction Analysis ◽  
Superconducting State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Thin Films ◽  
Thermal Stability Of

Superconducting characteristics and the thermal stability of sputtered, tungsten-based, amorphous thin films are investigated. Electronic properties and crystalline structures are analyzed as a function of the metalloid content in the films. It is well known that the superconducting Tc of a bulk crystalline tungsten is 0.01 K, which is one of the lowest transition temperatures among the superconducting metals. We have found that the W film containing 5 to 70 at. % metalloids exhibits a great enhancement in Tc. In the region of 15 to 35 at. % metalloids, the Tc shows the maximum of 5.0 K, and the transition from normal to superconducting state occurs very sharply. SEM observation together with x-ray diffraction analysis indicates that these films are amorphous in structure. The electrical resistivity is about 150 μΩ-cm, and shows little temperature dependence from Tc to 300 K. In addition, the W–Si amorphous superconductor is thermally very stable after annealing at 700 °C, but the W–Ge amorphous alloy crystallizes at 600 °C.

Amorphization Behavior of Ni57Zr20Ti22Ge1 Powders by Mechanical Alloying

2011 ◽  
Vol 479 ◽  
pp. 48-53
Author(s):  
Kai Chen Kuo ◽  
Pee Yew Lee ◽  
Jai Yush Yen
Keyword(s):  
Thermal Stability ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Atomic Size ◽  
X Ray ◽  
Amorphous Powders ◽  
Thermal Stability Of

In the current study, the amorphization behavior of mechanically alloyed Ni57Zr20Ti22Ge1 powder was examined in details. The conventional X-ray diffraction results confirm that the fully amorphous powders formed after 5 hours of milling. The thermal stability of the Ni57Zr20Ti22Ge1 amorphous powders was investigated by differential scanning calorimeter (DSC). As the results demonstrated, the glass transition temperature (Tg) and the crystallization temperature (Tx) are 761 K and 839 K, respectively. The supercooled liquid region ΔT is 78 K. The appearance of wide supercooled liquid region may be mainly due to the Ge additions which cause the increasing differences in atomic size of mechanically alloyed Ni57Zr20Ti22Ge1 powders.

scholarly journals A Study of Thin Film Resistors Prepared Using Ni-Cr-Si-Al-Ta High Entropy Alloy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ruei-Cheng Lin ◽  
Tai-Kuang Lee ◽  
Der-Ho Wu ◽  
Ying-Chieh Lee
Keyword(s):  
Annealing Temperature ◽  
Phase Evolution ◽  
Amorphous Structure ◽  
High Entropy Alloy ◽  
X Ray Diffraction ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
High Entropy ◽  
Transmission Electron ◽  
Thin Film Resistors

Ni-Cr-Si-Al-Ta resistive thin films were prepared on glass and Al2O3substrates by DC magnetron cosputtering from targets of Ni0.35-Cr0.25-Si0.2-Al0.2casting alloy and Ta metal. Electrical properties and microstructures of Ni-Cr-Si-Al-Ta films under different sputtering powers and annealing temperatures were investigated. The phase evolution, microstructure, and composition of Ni-Cr-Si-Al-Ta films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Auger electron spectroscopy (AES). When the annealing temperature was set to 300°C, the Ni-Cr-Si-Al-Ta films with an amorphous structure were observed. When the annealing temperature was at 500°C, the Ni-Cr-Si-Al-Ta films crystallized into Al0.9Ni4.22, Cr2Ta, and Ta5Si3phases. The Ni-Cr-Si-Al-Ta films deposited at 100 W and annealed at 300°C which exhibited the higher resistivity 2215 μΩ-cm with −10 ppm/°C of temperature coefficient of resistance (TCR).

Structure and Electrochemical Behavior of Plasma-Sprayed LSGM Electrolyte Films

2002 ◽  
Vol 756 ◽  
Author(s):  
H. Zhang ◽  
X. Ma ◽  
J. Dai ◽  
S. Hui ◽  
J. Roth ◽  
...  
Keyword(s):  
Electrochemical Behavior ◽  
Electrochemical Impedance ◽  
Amorphous Structure ◽  
Solid Oxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spray Process ◽  
Plasma Spray Process ◽  
Electrolyte Film ◽  
Plasma Sprayed

ABSTRACTAn intermediate temperature solid oxide fuel cell (SOFC) electrolyte film of La0.8Sr 0.2Ga0.8Mg0.2O2.8 (LSGM) was fabricated using a plasma spray process. The microstructure and phase were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical behavior of the thermal sprayed LSGM film was investigated using electrochemical impedance spectroscopy (EIS). The study indicates that thermal spray can deposit a dense LSGM layer. It was found that the rapid cooling in the thermal process led to an amorphous or poor crystalline LSGM deposited layer. This amorphous structure has a significant effect on the performance of the cell. Crystallization of the deposited LSGM layer was observed during annealing between 500–600 °C. After annealing at 800 °C, the ionic conductivity of the sprayed LSGM layer can reach the same level as that of the sintered LSGM.

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