scholarly journals Experimental Study on Zn-Doped Al-Rich Alloys for Fast on-Board Hydrogen Production

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 167 ◽  
Author(s):  
Dan Liu ◽  
Qian Gao ◽  
Qi An ◽  
Hongchao Wang ◽  
Jilun Wei ◽  
...  
Keyword(s):  
Experimental Study ◽  
Hydrogen Production ◽  
Production Performance ◽  
Hydrogen Production Rate ◽  
X Ray ◽  
Casting Technique ◽  
Zn Content ◽  
Different Temperatures ◽  
Rich Alloy ◽  
Scanning Electron

For the purpose of investigating the effect of Zn replacement of In3Sn on the hydrogen production performance of Al-rich alloy ingots, Al-Ga-In3Sn alloys with various Zn dosages (0–5 wt.%) were prepared by a traditional melting and casting technique. The phase compositions and microstructures were characterized using X-ray diffractometer (XRD) and scanning electron microscope (SEM) with an Energy Dispersed X-ray system (EDS). The SEM results indicate that, with a small amount of Zn instead of In3Sn, the number and total area of grain boundary (GB) phases will decrease gradually, and the average single GB area will eventually stabilize. The distribution of Zn in the alloy is similar to that of Ga, and an area with high Zn content appeared in the high-Zn-doped sample. The melting behaviors of Al with other metals were measured by DSC. The reaction of these alloys and water were investigated at different temperatures. Compared with Al-Ga-In3Sn alloy, low addition of Zn changed the composition of GB phase and increased the maximum hydrogen production rate. The reason for the changes in the hydrolysis reaction of Al with the addition of Zn was discussed.

Microstructure and Properties of Nanosemicrystalline Si3N4 Ceramics with Doped Sintering Additives: Part II. Phase Transformation and Microstructural Control

1998 ◽  
Vol 13 (9) ◽  
pp. 2588-2596 ◽  
Author(s):  
K. H. Ryu ◽  
J-M. Yang
Keyword(s):  
Electron Microscopy ◽  
Pressureless Sintering ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sintering Additives ◽  
Different Temperatures ◽  
Si3n4 Ceramics ◽  
Scanning Electron ◽  
Microstructural Control

The low temperature pressureless sintering of a nanosized Si3N4 powder with doped sintering additives was investigated. The microstructural evolution during sintering at different temperatures was analyzed using x-ray diffraction and scanning electron microscopy. The effect of using nanosized Si3N4 powder as a catalyst to accelerate the α→β–Si3N4 transformation of a commercial Si3N4 powder with larger particle sizes was also investigated. Finally, two stage sintering was used to study the feasibility of controlling the microstructure and the mechanical properties of the nanosized silicon nitride.

Microstructural and Corrosion Studies by Immersion in 3.5% NaCl Solution on Aged Mg-9Al-1Zn-XCa Alloy

2019 ◽  
Vol 969 ◽  
pp. 93-97
Author(s):  
S. Manivannan ◽  
B. Narenthiran ◽  
A. Sivanantham ◽  
S.P. Kumaresh Babu
Keyword(s):  
Corrosion Behaviour ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Corrosion Attack ◽  
X Ray ◽  
Α Phase ◽  
Corrosion Studies ◽  
Different Temperatures ◽  
Xrd Techniques ◽  
Scanning Electron

The experimatal alloys were aged at different temperatures of 180°C, 200°C, 220°C, and 240º C with calcium addition levels of (X=0.5, 1, 1.5, 2%) on Mg-6Al-1Zn-XCa alloy were investigated in 3.5% NaCl solution. All the experimatal alloys were immersed in 3.5% NaCl solutions and the resulted surface were analyzed to study the corrosion behaviour and its surface topography by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersed spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The result shows that corrosion attack occurred predominantly on ß phase and α phase exhibit relatively minor corrosion. In addition to that the increased aging temperature coarsens the intermetallic as well as α- Mg grains, which shows adverse effect to corrosion resistances and the best result were obtained at composition of 0.5wt.% Ca aged at 200°C.

scholarly journals Experimental Study of Phase Composition of B-Fe-Mn-V Alloys and Thermodynamic Calculations of Phase Equilibria in the B-Mn-V and B-Fe-Mn-V Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Viera Homolová ◽  
Ján Kepič ◽  
Adéla Zemanová ◽  
Ondřej Zobač
Keyword(s):  
Electron Microscopy ◽  
Experimental Study ◽  
Quaternary System ◽  
Experimental Methods ◽  
Calphad Method ◽  
Thermodynamic Calculations ◽  
Interstitial Element ◽  
X Ray ◽  
Scanning Electron ◽  
Good Agreement

Phase compositions of B-Fe-Mn-V alloys were studied by several experimental methods (DTA measurement, X-ray diffractions, and scanning electron microscopy). Besides the experimental study of the quaternary system, thermodynamic modelling of the ternary B-Mn-V system by the Calphad method and thermodynamic calculations for the quaternary B-Fe-Mn-V system were performed. Calculations for the quaternary system are based on the ternary subsystems (B-Mn-V, B-Fe-V, B-Fe-Mn, and Fe-Mn-V). Boron is modelled as an interstitial element in all solid solutions of vanadium, manganese, and iron. Very good agreement between experimental results and thermodynamic calculations was achieved. The created thermodynamic database is suitable for thermodynamic calculations of phase diagrams for all the ternary subsystems and also for the B-Fe-Mn-V quaternary system.

Corrosion of High Zn Content Al-Zn-Mg-Cu Alloy in 3.5 wt.% NaCl Solution

2014 ◽  
Vol 703 ◽  
pp. 21-28
Author(s):  
Fan Qing Ran ◽  
Zi Yong Chen ◽  
Li Hua Chai
Keyword(s):  
Corrosion Process ◽  
Localized Corrosion ◽  
Nacl Solution ◽  
X Ray ◽  
Second Stage ◽  
Cu Alloy ◽  
Zn Content ◽  
The Matrix ◽  
Two Stages ◽  
Scanning Electron

In this paper, the polished specimens of high Zn content Al-Zn-Mg-Cu alloy after various aging treatments were immersed in 3.5 wt.% NaCl for up to 240 mins. The development of corrosion was monitored using scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX). There are two stages during the corrosion process, the first stage of attack started with localized corrosion of trenching around the Al-Zn-Mg-Cu particles. In the second stage the pitting corrosion appeared at the grain boundaries, and then developed into intergranular corrosion. This phenomenon is related to the potential difference between the matrix and the precipitates.

Experimental Study on Combustion Reaction between Silicon and Nitrogen in Transport Bed

2013 ◽  
Vol 860-863 ◽  
pp. 1374-1377
Author(s):  
Shao Wu Yin ◽  
Li Wang ◽  
Li Ge Tong ◽  
Chuan Ping Liu ◽  
Xing Long Zheng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Experimental Study ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Combustion Reaction ◽  
X Ray Diffraction ◽  
Amorphous Silicon Nitride ◽  
X Ray ◽  
Scanning Electron

Combustion reaction between silicon powders and nitrogen in transport bed was studied. The reaction temperature ranged from 1523 to 1653 K, and the reaction time ranged from 0 to 2.7 min. The phase compositions, morphologies and chemical composition of the products were analyzed by X-ray diffraction, scanning electron microscopy and O/N determinater, respectively. The experimental results showed, in the case of silicon powders with particle size of 2.2 μm, the conversion rate of silicon was 61.9% at reaction temperature of 1653 K and reaction time of 2.7min, and the products mainly comprised amorphous silicon nitride powders.

Novel Hierarchical TiO2/C Nanocomposite with Enhanced Photocatalytic Performance

NANO ◽  
2015 ◽  
Vol 10 (05) ◽  
pp. 1550064 ◽  
Author(s):  
Yupeng Gao ◽  
Hao Chen ◽  
Aiguo Zhou ◽  
Zhengyang Li ◽  
Fanfan Liu ◽  
...  
Keyword(s):  
Photocatalytic Performance ◽  
Photocatalytic Property ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Carbon Nanocomposites ◽  
Carbon Nanosheets ◽  
X Ray ◽  
The Hierarchical Structure ◽  
Different Temperatures ◽  
Scanning Electron

Hierarchical TiO 2/carbon nanocomposites were synthesized by oxidation of two-dimensional (2D) Ti 3 C 2 nanosheets at different temperatures. Crystal structures and morphologies of the obtained samples were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and Raman spectroscopy. The results show that 2D Ti 3 C 2 nanosheets are partially oxidized to form a novel hierarchical nanostructure which is composed of carbon nanosheets and TiO 2 nanoparticles. With the calcination temperature increasing, the crystal structure of TiO 2 nanoparticles changes from anatase to rutile and the hierarchical structure was gradually destroyed. The photodegradation results reveal that the samples obtained at 200°C and 285°C show much better photocatalytic properties than P25. And meanwhile the photocatalytic property will become worse with the increase in calcinations temperature.

scholarly journals Synthesis and Catalase Mimic Activity of MnO2 Nano Powder Prepared by Hydrothermal Process

2019 ◽  
Vol 27 (2) ◽  
pp. 228-237 ◽  
Author(s):  
Rashed T. Rasheed ◽  
Sariya D. Al-Algawi ◽  
Rosul M. N.
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Annealing Temperature ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Atomic Force ◽  
Different Temperatures ◽  
Scanning Electron

Manganese dioxide (MnO2) nanopowder has been synthesized by hydrothermal method. MnO2 was annealed at different temperatures (250, 400, 550, 700˚C). The crystal structure and surface morphology of these nanostructures were characterized by X-ray diffraction (XRD), Atomic Force Microscope (AFM) and Scanning Electron Microscopy (SEM). The catalase mimic activity (catalytic activity) of MnO2 against hydrogen peroxide (H2O2) was studied by using the new method and found that 400˚C is the best annealing temperature.

scholarly journals Effects of annealing parameters on phase, structure and thermochromic properties of VO2 (M) derived from nanostructured VO2(B)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamdi Muhyuddin Barra ◽  
Soo Kien Chen ◽  
Nizam Tamchek ◽  
Zainal Abidin Talib ◽  
Oon Jew Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Different Temperatures ◽  
Thermochromic Properties ◽  
Scanning Electron

Abstract Synthesis of thermochromic VO2 (M) was successfully done by annealing hydrothermally-prepared VO2 (B) at different temperatures and times. Conversion of the metastable VO2 (B) to the thermochromic VO2 polymorph was studied using thermogravimetric analyzer (TGA) under N2 atmosphere. Moreover, the phase and morphology of the synthesized samples were studied using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. Accordingly, the XRD scans of all the annealed samples exhibited the presence of monoclinic VO2 (M), while the FE-SEM images of the samples showed the formation of nanorods and nanospheres, particularly those heated at high temperatures (650 °C and 700 °C). Meanwhile, differential scanning calorimetry (DSC) was used to measure the phase transition temperature (τc), hysteresis, and enthalpy of the prepared VO2. Based on these results, all samples displayed a τc of about 66 °C. However, the hysteresis was high for the samples annealed at lower temperatures (550 °C and 600 °C), while the enthalpy was very low for samples heated at lower annealing time (1.5 h and 1 h). These findings showed that crystallinity and nanostructure formation affected the thermochromic properties of the samples. In particular, the sample annealed at 650 °C showed better crystallinity and improved thermochromic behavior.

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