CRYSTALLIZATION BEHAVIOR OF AMORPHOUS TI-NI-CU ALLOY RIBBONS

2008 ◽  
Vol 01 (02) ◽  
pp. 145-149 ◽  
Author(s):  
JUNG MIN NAM ◽  
YONG HEE LEE ◽  
TAE HYUN NAM ◽  
YEON WOOK KIM ◽  
JUNG MOO LEE

Amorphous Ti 50 Ni (50-x) Cu x (at.%) (x = 15, 20 and 25) alloy ribbons were prepared by melt spinning, and then their crystallization behavior was investigated by optical microscopy, transmission electron microscopy, X-ray diffraction and differential scanning calorimetry. Wavenumber (Qp) decreased from 29.40 nm-1 to 29.29 nm-1 and ΔT(T g - T x ) increased from 31 K to 36 K with increasing Cu content from 15 at.% to 25 at.%, suggesting that glass forming ability of Ti – Ni – Cu alloy ribbons increased with increasing Cu content. Activation energy for crystallization decreased from 211.5 kJ/mol to 136.4 kJ/mol with increasing Cu content from 15 at.% to 25 at.%, suggesting that a stability of Ti – Ni – Cu amorphous decreased with increasing Cu content.

2009 ◽  
Vol 79-82 ◽  
pp. 191-194
Author(s):  
Hao Ran Geng ◽  
Yan Bo Deng ◽  
Zhi Ming Wang ◽  
Xue Liang Wang ◽  
Zhen Yuan Li

The relationship between the viscosity of Al84Mg10Ce6 alloy melt and liquid structure was studied by viscosity measurements, X-ray diffraction and DSC analysis in this paper. In addition, the glass forming ability of alloy ties produced by melt spinning was analyzed. Based on the above results, the relationship between alloy melts and its glass forming ability(GFA)was studied. The addition of element Ce leads to the abnormal change of Al84Mg10Ce6 melt’ s structure and enhances its GFA, furthermore, it results in completely amorphous ties with melt spinning at 850°C.Therefore, there is certain relationship between the Al-Mg based alloys melt and its GFA.


2002 ◽  
Vol 17 (5) ◽  
pp. 1014-1018 ◽  
Author(s):  
Dmitri V. Louzguine ◽  
Akihisa Inoue

The present paper reports the effect of partial replacement of Ni by Cu in the Al85Y8Ni5Co2 alloy. The studied alloys were produced by rapid solidification. Glass-formation, crystallization behavior, and stability of the supercooled liquid were studied by x-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. Partial replacement of Ni by Cu in the Al85Y8Ni5Co2 metallic glass caused formation of the nanoscale α–Al particles and resulted in a decrease in the crystallization temperature and disappearance of the supercooled liquid.


2005 ◽  
Vol 475-479 ◽  
pp. 3393-3396
Author(s):  
Hui Xu ◽  
Xiao Hua Tan ◽  
Nannan Qi ◽  
Qing Wang ◽  
Yuanda Dong

The glass-forming ability, thermal stability and magnetic properties of the Nd60-xDyxFe30Al10 (x=0, 2, 5) bulk amorphous alloys were investigated by x-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and the vibrating sample magnetometer (VSM). The results show that the glass forming ability of the Nd60-xDyxFe30Al10 (x=0, 2, 5) alloys decrease with increasing Dy content. The as-cast Nd60-xDyxFe30Al10 (x=0, 2, 5) alloys show hard magnetic behavior at room temperature. With increasing Dy content, the intrinsic coercivity of the alloys increase significantly while the saturation magnetization and remanence of the alloys decrease monotonously. With increasing annealed temperature, the intrinsic coercivity of the Nd55Fe30Al10Dy5 alloy decreased significantly, while the saturation magnetization and remanence decrease monotonously. The Nd55Fe30Al10Dy5 alloy shows soft magnetic behavior after annealed at 773K for 30 min.


2012 ◽  
Vol 583 ◽  
pp. 82-85
Author(s):  
Yong Jun Tang ◽  
Hui Xu ◽  
Xiao Hua Tan ◽  
Hua Man ◽  
Qin Bai

Bulk Nd60-xCo15+xAl25 (where x =0, 2, 5, 8, 11) sheet alloys were prepared by argon arc melting and suction casting a copper mold. Glassing forming ability (GFA) of these alloys was investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Due to the dissimilarity reflected from DSC curves the thermodynamic calculation was applied. The values of Gibbs free energy (∆Gl-x (Tg)) for the amorphous alloys were gave out and some GFA criterions were adopted to make a comparison among the samples.


2012 ◽  
Vol 271-272 ◽  
pp. 36-41
Author(s):  
Wei Yuan Yu ◽  
Wen Jiang Lu ◽  
Nai Rui Li

Al85Ni10Zr3Y2 and Al80Ni10Zr8-xCuxY2(x=1,2,3,5) alloy ribbons had been prepared by single roller melt-spinning process under vacuum conditions. The ribbons were investigated by X–ray diffraction and differential scanning calorimetry (DSC). The results revealed the strong effect of content of Cu、Zr elements on the glass forming ability and the thermal stability of the alloys. The formation of amorphous alloys are sensitive to contens of these two elements. The completely amorphous alloy or the primary amorphous phase alloy can be obtained when the content of Cu or Zr reach an optimization, otherwise only gaining crystal phase. Al80Ni10Zr7Cu1Y2 and Al80Ni10Zr3Cu5Y2 alloys possess the excellent glass forming ability, which can form the completely amorphous alloy or the composite material of the partial crystal in remaining amorphous.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3433
Author(s):  
Aleksandra Kolano-Burian ◽  
Przemyslaw Zackiewicz ◽  
Agnieszka Grabias ◽  
Anna Wojcik ◽  
Wojciech Maziarz ◽  
...  

In the present work, we investigated in detail the thermal/crystallization behavior and magnetic properties of materials with Fe84.5-xCoxNb5B8.5P2 (x = 0, 5, 10, 15 and 20 at.%) composition. The amorphous ribbons were manufactured on a semi-industrial scale by the melt-spinning technique. The subsequent nanocrystallization processes were carried out under different conditions (with/without magnetic field). The comprehensive studies have been carried out using differential scanning calorimetry, X-ray diffractometry, transmission electron microscopy, hysteresis loop analyses, vibrating sample magnetometry and Mössbauer spectroscopy. Moreover, the frequency (up to 300 kHz) dependence of power losses and permeability at a magnetic induction up to 0.9 T was investigated. On the basis of some of the results obtained, we calculated the values of the activation energies and the induced magnetic anisotropies. The X-ray diffraction results confirm the surface crystallization effect previously observed for phosphorous-containing alloys. The in situ microscopic observations of crystallization describe this process in detail in accordance with the calorimetry results. Furthermore, the effect of Co content on the phase composition and the influence of annealing in an external magnetic field on magnetic properties, including the orientation of the magnetic spins, have been studied using various magnetic techniques. Finally, nanocrystalline Fe64.5Co20Nb5B8.5P2 cores were prepared after transverse thermo-magnetic heat treatment and installed in industrially available portable heating equipment.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Xianjie Yuan ◽  
Xuanhui Qu ◽  
Haiqing Yin ◽  
Zaiqiang Feng ◽  
Mingqi Tang ◽  
...  

This present work investigates the effects of sintering temperature on densification, mechanical properties and microstructure of Al-based alloy pressed by high-velocity compaction. The green samples were heated under the flow of high pure (99.99 wt%) N2. The heating rate was 4 °C/min before 315 °C. For reducing the residual stress, the samples were isothermally held for one h. Then, the specimens were respectively heated at the rate of 10 °C/min to the temperature between 540 °C and 700 °C, held for one h, and then furnace-cooled to the room temperature. Results indicate that when the sintered temperature was 640 °C, both the sintered density and mechanical properties was optimum. Differential Scanning Calorimetry, X-ray diffraction of sintered samples, Scanning Electron Microscopy, Energy Dispersive Spectroscopy, and Transmission Electron Microscope were used to analyse the microstructure and phases.


2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.


1991 ◽  
Vol 246 ◽  
Author(s):  
J.A. Horton ◽  
E.P. George ◽  
C.J. Sparks ◽  
M.Y. Kao ◽  
O.B. Cavin ◽  
...  

AbstractA survey by differential scanning calorimetry (DSC) and recovery during heating of indentations on a series of nickel-aluminum alloys showed that the Ni-36 at.% Al composition has the best potential for a recoverable shape memory effect at temperatures above 100°C. The phase transformations were studied by high temperature transmission electron microscopy (TEM) and by high temperature x-ray diffraction (HTXRD). Quenching from 1200°C resulted in a single phase, fully martensitic structure. The initial quenched-in martensites were found by both TEM and X-ray diffraction to consist of primarily a body centered tetragonal (bct) phase with some body centered orthorhombic (bco) phase present. On the first heating cycle, DSC showed an endothermic peak at 121°C and an exothermic peak at 289°C, and upon cooling a martensite exothermic peak at 115° C. Upon subsequent cycles the 289°C peak disappeared. High temperature X-ray diffraction, with a heating rate of 2°C/min, showed the expected transformation of bct phase to B2 between 100 and 200°C, however the bco phase remained intact. At 400 to 450°C the B2 phase transformed to Ni2Al and Ni5Al3. During TEM heating experiments a dislocation-free martensite transformed reversibly to B2 at temperatures less than 150°C. At higher temperatures (nearly 600°C) 1/3, 1/3, 1/3 reflections from an ω-like phase formed. Upon cooling, the 1/3, 1/3, 1/3 reflections disappeared and a more complicated martensite resulted. Boron additions suppressed intergranular fracture and, as expected, resulted in no ductility improvements. Boron additions and/or hot extrusion encouraged the formation of a superordered bct structure with 1/2, 1/2, 0 reflections.


2000 ◽  
Vol 15 (7) ◽  
pp. 1617-1621 ◽  
Author(s):  
Jan Schroers ◽  
Konrad Samwer ◽  
Frigyes Szuecs ◽  
William L. Johnson

The reaction of the bulk glass forming alloy Zr41Ti14Cu12Ni10Be23 (Vit 1) with W, Ta, Mo, AlN, Al2O3, Si, graphite, and amorphous carbon was investigated. Vit 1 samples were melted and subsequently solidified after different processing times on discs of the different materials. Sessile drop examinations of the macroscopic wetting of Vit 1 on the discs as a function of temperature were carried out in situ with a digital optical camera. The reactions at the interfaces between the Vit 1 sample and the different disc materials were investigated with an electron microprobe. The structure and thermal stability of the processed Vit 1 samples were examined by x-ray diffraction and differential scanning calorimetry. The results are discussed in terms of possible applications for composite materials.


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