The Effect of Hydrogen on an Iron Based Amorphous Alloy

1981 ◽  
Vol 8 ◽  
Author(s):  
H. Shahani ◽  
H. Soderhjelm ◽  
Mats Nygren

ABSTRACTIn this· investigation we have systematically studied the brittleness and the atomic structure in an Fe(SiBC) alloy. Different amounts of hydrogen have been dissolved in the alloy. It has then been studied at different cooling rates.Hydrogen gas of different partial pressures was dissolved into the melt. The alloy was then rapidly quenched by a chill block melt spinning method. The cooling rates were changed by changing the velocity on the chilling roll. The brittleness and the atomic structure were examined by bending tests and x-ray diffraction.X-ray diffractions showed that the ribbons were amorphous when the cooling rate was sufficient. Amorphous ribbons without any hydrogen were ductile, crystalline ribbons of this alloy were brittle. The ribbons with dissolved hydrogen and amorphous structure were brittle even at small amounts of hydrogen. At the highest cooling rates the ribbons with low hydrogen content were ductile. There seems to be a connection between the hydrogen content and the amorphous ribbons ductility. The hydrogen content only has a slight influence to amorphous structure.

2021 ◽  
Vol 21 (4) ◽  
pp. 79-89
Author(s):  
Muhammed Fatih Kılıçaslan ◽  
Yasin Yılmaz ◽  
Bekir Akgül ◽  
Hakan Karataş ◽  
Can Doğan Vurdu

Abstract Alloys of FeNiSiB soft magnetic materials containing variable Fe and Ni contents (wt.%) have been produced by melt spinning method, a kind of rapid solidification technique. The magnetic and structural properties of FeNiSiB alloys with soft magnetic properties were investigated by increasing the Fe ratio. X-ray diffraction analysis and SEM images shows that the produced alloy ribbons generally have an amorphous structure, together with also partially nanocrystalline regions. It was observed that the structure became much more amorphous together with increasing Fe content in the composition. Among the alloy ribbons, the highest saturation magnetization was obtained as 0.6 emu/g in the specimen with 50 wt.% Fe. In addition, the highest Curie temperature was observed in the sample containing 46 wt.% Fe.


2016 ◽  
Vol 849 ◽  
pp. 629-635
Author(s):  
Jing Hui Song ◽  
Sheng Jie He ◽  
Qi Sheng Xu ◽  
Fei Fei Liang ◽  
Yong Hou ◽  
...  

The Fe-based amorphous ribbons were prepared by the copper roller melt spinning method, and then the laser brazing was carried out using the amorphous ribbons as the brazing filler metal. Subsequently, laser was used to melt and brazed the plain steel and stainless steel whose surfaces had been pre-coated with the Fe-based amorphous brazing. The micro Vickers hardness tester, metallographic microscope, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the hardness, morphology, microstructure and composition distribution of the welded joints, respectively. The results showed that the prepared amorphous ribbons were of fully amorphous structure. The ordinary steel and stainless steel were well-connected, and mutual dissolution and diffusion had occurred between the solder and the base metal, which achieved the metallurgical bonding. The Fe-based amorphous ribbons were used to solder heterogeneous sheet metals that were difficult to be welded directly. New attempts were made in the hard-connected metal plate field, and the paper could provide concrete references for soldering metals with low invasion, which is of great significance in promoting the development and application of amorphous brazing.


2012 ◽  
Vol 57 (4) ◽  
pp. 1031-1039
Author(s):  
H. Solomon ◽  
N. Solomon

The goal of this paper is to present the influence of temperature variation and iron substitution with Co on the structure and electrical properties of amorphous Fe75-xCoxCr1B7Si17 alloys (where x=1, 4, 7, and 10 at.%), obtained by melt-spinning technique. The electrical resistivity of the samples was measured by using a usual four-probe method from -160°C to 750°C. The electrical resistivity was also measured at room temperature for the amorphous Fe75-xCoxCr1B7Si17 ribbons annealed at various temperatures for different holding time. The annealed samples were also investigated by Vickers microhardness test. The amorphous structure of tested materials was examined by X-ray diffraction (XRD), Mossbauer spectroscopy, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) methods. Experimental results confirmed the utility of applied investigation methods and the influence of the Co content and annealing process on the crystallization, structure and electrical properties of examined amorphous alloys.


1983 ◽  
Vol 28 ◽  
Author(s):  
C. R. Shastry ◽  
R. M. Latanision ◽  
H. E. Townsend

ABSTRACTRapidly solidified ribbons of Fe67Ti13P(20-x)Bx (x= 0, 7, 20 a/o) and Fe(85-y)Ti l5Py (y=5, 10 a/o) alloys were produced by melt spinning, and their structure and anodic polarization behavior were examined by x-ray diffraction and potentio-dynamic polarization measurements in deaerated 1 N H2SO4, respectively. The only alloy that developed an amorphous structure on rapid solidification, Fe67Ti13B20, exhibited poor corrosion resistance, whereas crystalline alloys with 10 a/o or more P exhibited a tendency to passivate during anodic polarization. Substituting Cr for Ti led to significant improvement in corrosion resistance and promoted development of glassy structures in Fe67(TiCr)13P13B7 compositions. No such improvements were observed when Cu was substituted for Ti. It is concluded that alloy composition is more important than degree of crystallinity in determining corrosion resistance.


2020 ◽  
Author(s):  
Chi-Toan Nguyen ◽  
Alistair Garner ◽  
Javier Romero ◽  
Antoine Ambard ◽  
Michael Preuss ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ruei-Cheng Lin ◽  
Tai-Kuang Lee ◽  
Der-Ho Wu ◽  
Ying-Chieh Lee

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).


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Nur Aimi Jani ◽  
Choonyian Haw ◽  
Weesiong Chiu ◽  
Saadah Abdul Rahman ◽  
Poisim Khiew ◽  
...  

Current work reports the study of Ag nanocrystals (NCs) decorated doubly anodized (DA) TiO2 nanotubes (NTs) thin film as an efficient photoelectrode material for water splitting and photocatalytic hydrogen gas production. DA process has been shown to be capable of producing less defective NTs and creating additional spacious gaps in between NT bundles to allow efficient and uniform integration of Ag NCs. By employing photoreduction method, Ag NCs can be deposited directly onto NTs, where the size and density of coverage can be maneuvered by merely varying the concentration of Ag precursors. Field emission scanning electron microscope (FESEM) images show that the Ag NCs with controllable size are homogeneously decorated onto the walls of NTs with random yet uniform distribution. X-ray diffraction (XRD) results confirm the formation of anatase TiO2 NTs and Ag NCs, which can be well indexed to standard patterns. The decoration of metallic Ag NCs onto the surface of NTs demonstrates a significant enhancement in the photoconversion efficiency as compared to that of pristine TiO2 NTs. Additionally, the as-prepared nanocomposite film also shows improved efficiency when used as a photocatalyst platform in the production of hydrogen gas. Such improvement in the performance of water splitting and photocatalytic hydrogen gas production activity can be credited to the surface plasmonic resonance of Ag NCs present on the surface of the NTs, which renders improved light absorption and better charge separation. The current work can serve as a model of study for designing more advanced nanoarchitecture photoelectrode for renewable energy application.


2002 ◽  
Vol 756 ◽  
Author(s):  
H. Zhang ◽  
X. Ma ◽  
J. Dai ◽  
S. Hui ◽  
J. Roth ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document