PREPARATION AND CHARACTERIZATION OF AMORPHOUS ALLOY/POROUS SiCBi-CONTINUOUS STRUCTURE COMPOSITE

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1294-1299 ◽  
Author(s):  
YONGLI CHEN ◽  
AIMIN WANG ◽  
HAIFENG ZHANG ◽  
ZHUANGQI HU
Keyword(s):  
Thermal Properties ◽  
Amorphous Alloy ◽  
Three Dimensional ◽  
Amorphous State ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Continuous Structure ◽  
Porous Sic

A new kind of composite with a bi -continuous structure was produced by pressure infiltrating melt Zr 41.2 Ti 13.8 Cu 12.5 Ni 10 Be 22.5 into porous SiC which was made by powder metallurgy. Microstructure investigations of the composite show that the melt alloy was fully infiltrated into the voids of porous SiC and quenched into amorphous state. Both the amorphous alloy and the porous SiC exhibit a three-dimensional interconnected net structure. The study of thermal properties reveals that the addition of porous SiC reduces the width of supercooled liquid region of the composite. The bi -continuous composite presents 2% plastic strain and ultimate strength of 1250MPa.

Preparation and Characterization of Fe36Co36B20Si4Nb4 Nanocrystalline/Amorphous Matrix Composite

2011 ◽  
Vol 391-392 ◽  
pp. 778-782
Author(s):  
Gang Li ◽  
Zhan Zhe Zhang
Keyword(s):  
Amorphous Alloy ◽  
Matrix Composite ◽  
Amorphous Matrix ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Annealing Conditions ◽  
Nanocrystalline Particles ◽  
Nanocrystalline Phases

In this paper, we report a Fe-based nanocrystalline-amorphous matrix composite synthesised via partially crystallising an amorphous alloy. The microstructure of the composite was characterize. An amorphous rod of 2mm in diameter was initially prepared via injecting the melted Fe36Co36B20Si4Nb4 alloy into a copper mould in vacuum, which was confirmed to be completely amorphous by X-ray difraction（XRD）. Differential scanning calorimeteric（DSC）curve shown that the span △Tx of the supercooled liquid region and the reduced glass transition temperature（Tg/Tm）for the amorphous alloy are 40 K and 0.615, respectively. The composite composed of nanocrystalline particles homogeneously dispersed in an amorphous matrix was prepared by isothermal annealing. In this course, the amorphous Fe-based sample was held for different time at different temperature. The types of the nanocrystalline phases obtained in different annealing conditions were characterised by XRD and selected-area diffraction pattern（SAED）.The crystallization behavior of the amorphous Fe-based alloy was discussed.

scholarly journals Crystallization Behavior of Al70Fe12.5V12.5Nb5 Amorphous Alloy Formed by Mechanical Alloying

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 383 ◽  
Author(s):  
Xuan Liu ◽  
Xingfu Wang ◽  
Yongli Si ◽  
Xiaokang Zhong ◽  
Fusheng Han
Keyword(s):  
Amorphous Alloy ◽  
Mechanical Alloying ◽  
Amorphous Alloys ◽  
Crystallization Behavior ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Liquid Region ◽  
Application Field ◽  
Glass Forming

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.

scholarly journals Static and Dynamic Thermal Properties of a Pd40Ni40Si20 Glassy Alloy

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1157
Author(s):  
Ludmil Drenchev ◽  
Tony Spassov ◽  
Georgi Stefanov ◽  
Akihisa Inoue ◽  
Stoyko Gyurov
Keyword(s):  
Thermal Properties ◽  
Glassy Alloy ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Dynamic Measurement ◽  
Measurement Methods ◽  
Liquid Region ◽  
Transport Barrier ◽  
Glassy Alloys ◽  
Atomic Transport

The thermal properties of a Pd40Ni40Si20 glassy alloy with the largest supercooled liquid region among the glassy alloys containing Si as a metalloid element are studied using static and dynamic measurement methods. The relatively wide supercooled liquid region of 45 K, defined by the temperature interval between the glass transition temperature (Tg) and the onset temperature of crystallization (Tx), and the viscosity of the supercooled liquid, varying from 2.7 × 1010 to 3.2 × 1011 Pa·s, make this glass suitable for the introduction of controlled pores by a viscous flow in the temperature range Tg~Tx. The obtained activation energy for crystallization, 272 ± 19 kJ/mol, is slightly higher than that of Tg (228 ± 11 kJ/mol), indicating the dominant contribution of the atomic transport barrier in the overall energy barrier for crystallization.

Characteristics of Ti-Ni-Zr Thin Film Metallic Glasses / Thin Film Shape Memory Alloys for Micro Actuators with Three-Dimensional Structures

2015 ◽  
Vol 9 (6) ◽  
pp. 662-667 ◽  
Author(s):  
Junpei Sakurai ◽  
◽  
Seiichi Hata
Keyword(s):  
Thin Film ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Metallic Glasses ◽  
Microelectromechanical Systems ◽  
Three Dimensional ◽  
Eutectic Point ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region

In this paper, we investigate the characteristics of Ti-Ni-Zr thin film metallic glasses (TFMGs)/ shape memory alloys (SMAs) for microelectromechanical systems (MEMS) applications with three-dimensional structures. The amorphous Ti-Ni-Zr thin films having a Ni content of more than 50 at.% and Zr content of more than 11 at.% undergo glass transitions and are TFMGs. The Ti39Ni50Zr11TFMG has the lowest glass transition temperatureTgof 703 K and a wide supercooled liquid region ΔTof 57 K. Moreover, it has high thermal stability atTg. However, the apparent viscosity of the Ti39Ni50Zr11is higher than those of other Ti-Ni-Zr TFMGs. Moreover, the Ti-Ni-Zr TFMG exhibits higher viscosity than conventional TFMGs because the alloy composition of Ti-Ni-Zr TFMGs/SMAs is far from the eutectic point.

Diffusion in Zr55Al10Ni10Cu25 Amorphous Alloy with a Wide Supercooled Liquid Region

1997 ◽  
Vol 143-147 ◽  
pp. 837-842 ◽  
Author(s):  
K. Nonaka ◽  
Y. Kimura ◽  
Kiyoshi Yamauchi ◽  
Hideo Nakajima ◽  
T. Zhang ◽  
...  
Keyword(s):  
Amorphous Alloy ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region

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.

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