scholarly journals Effect of Dispersoids and Intermetallics on Hardening the Al-Si-Cu-Mg Cast Alloys

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
J. Hernandez-Sandoval ◽  
M. H. Abdelaziz ◽  
A. M. Samuel ◽  
H. W. Doty ◽  
F. H. Samuel
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Base Alloy ◽  
Average Particle Size ◽  
Research Work ◽  
Aging Treatment ◽  
Average Particle ◽  
Cast Aluminum ◽  
Poisoning Effect ◽  
Cast Alloys

The principal aim of the present research work was to compare the role of dispersoids Al2O3 (∼15 μm average particle size) and SiC (∼15 μm average particle size) with that offered by Zr- and Ni-based intermetallics (∼35–70 μm average particle size) on the hardening of cast aluminum 354 alloy (9.1% Si, 0.12% Fe, 1.8% Cu, 0.008% Mn, 0.6% Mg, and 87.6% Al) at ambient temperature. There is no observable poisoning effect on the refinement of grain size after the addition of Zr to the alloys investigated in this study. The tensile test results were examined in light of the microstructural features of the corresponding alloy samples. The contribution of the added dispersoids or Ni and Zr alloying elements on the tensile properties of the 354 alloys was determined employing ∆P plots (where P = Property, UTS, YS, or %El), using the base alloy (in the as-cast condition) as a reference point. The tensile results were supported by investigating the precipitation-hardening phases using scanning and transmission electron microscopy as well as examining the fracture surfaces of selected conditions applying field emission scanning electron microscopy. The results show that, in all cases, Al2Cu phase is the main hardening agent. The contribution of about 1.5 vol% of SiC or Al2O3 to the strength of the base alloy is higher than that offered by Zr- and Ni-based intermetallics, under the same aging treatment.

Synthesis and Characterization of Water-Soluble Monolayer-Protected Gold Nanoparticles

2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Average Particle Size ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Transmission Electron

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.

The Aggregation Study and Characterization of Silver Nanoparticles

2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Absorption Spectrum ◽  
Average Particle Size ◽  
Average Particle ◽  
Transmission Electron ◽  
Vis Spectroscopy

In this article, we have studied the process of silver nanoparticles (AgNPs) aggregation and to stop aggregation 0.3% Polyvinylpyrrolidone (PVP) was used. Aggregation study carried out via UV-vis spectroscopy and it is reported that the absorption spectrum of spherical silver nanoparticles were found a maximum peak at 420 nm wavelength. Furthermore, Transmission Electron Microscopy (TEM) were used to characterized the size and shape of AgNPs, where the average particle size is around 10 to 25 nm in diameter and the AgNPs shape is spherical. Next, Dynamic Light Scattering (DLS) were used, owing to observed size distribution and self-correlation of AgNPs.

Mechanical Properties of AA 5754 Hybrid Metal Matrix Composite Fabricated through Rheo-Squeeze Casting

2020 ◽  
Vol 979 ◽  
pp. 10-15
Author(s):  
K. Sekar ◽  
K. Jayakumar
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Metal Matrix ◽  
Squeeze Casting ◽  
Base Alloy ◽  
Average Particle Size ◽  
Casting Process ◽  
Matrix Alloy ◽  
Average Particle ◽  
The Impact

Hybrid metal matrix composites (MMCs) were prepared with AA 5754 as matrix and B4C (fixed with 1 wt.% and average particle size as 25 μm) and Al2O3 reinforcements (varied from 0.5 to 2 wt. % with the interval of 0.5 and average particle size as 50 nm) using Rheo-squeeze casting process. Microstructure images were taken to observe the uniform distribution of reinforcement particles on the matrix alloy. The tensile strength for AA 5754 with 1 wt.% B4C and 2 wt.% Al2O3 hybrid composite showed higher value compared to base alloy and other composites. The wt. % of Al2O3 in the composite is increased to 2 %, the tensile strength and compressive strength were also increased due to combined Rheo-squeeze casting. AA 5754 reinforced with 1 wt.% B4C and 1.5 wt.% Al2O3 MMC indicated the Impact strength value of 30 Joules which is higher than AA 5754 matrix alloy and other compositions.

Analysis of the Promoter-Catalyst interaction between Mn and Rh by Transmission Electron Microscopy

2014 ◽  
Vol 7 (1) ◽  
Author(s):  
B. Graham ◽  
R.F. Klie
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Average Particle Size ◽  
Lattice Parameter ◽  
Average Particle ◽  
Fischer Tropsch ◽  
Transmission Electron ◽  
Three Samples ◽  
Promoter Interaction

In the hope of optimizing the Fischer-Tropsch mechanism to produce cleaner ethanol, the catalyst- promoter interaction between rhodium and manganese was examined by transmission electron microscopy. Three samples were analyzed on a carbon nanotube (CNT) substrate with 3 wt% rhodium (3%Rh/CNT), 1% manganese with 3 wt% rhodium (1%Mn/3% Rh/CNT), and 2% manganese with 3 wt% rhodium (2% Mn/3% Rh/CNT). The average particle size were found to be (1.9 ± 0.6) nm, (2.1 ± 0.5) nm, and (3.2 ± 0.6) nm, respectively. An increase in particle size indicates that the rhodium and manganese are interacting. The lattice parameter for rhodium were also determined to be (4.1 ± 0.1) Å, (4.2 ± 0.1) Å, and (3.8 ± 0.1) Å, respectively. The decrease in lattice parameter in the 2%Mn/3%Rh/CNT sample was most likely due to a change in the crystal structure of the rhodium particles as a result of the interaction between the manganese and rhodium.

scholarly journals Preparation and Characterization of Ultra-Fine Oil Palm Ash Powder by Ultrasonication and Alkaline Treatment for Its Evaluation as Reinforcing Filler in Natural Rubber

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 100
Author(s):  
Methakarn Jarnthong ◽  
Chutarat Malawet ◽  
Lusheng Liao ◽  
Puwang Li ◽  
Zheng Peng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Natural Rubber ◽  
Oil Palm ◽  
Average Particle Size ◽  
Alkaline Treatment ◽  
Bet Surface Area ◽  
Average Particle ◽  
Naoh Solution ◽  
Oil Palm Ash

Ultra-fine oil palm ash (OPA) particles were successfully prepared using ultrasonication along with optimal chemical deagglomeration. The influence of chemical treatment by sodium hydroxide (NaOH) solution on the OPA particles was found to be an important factor in enhancing deagglomeration efficiency. The average particle size of the original OPA (41.651 μm) decreased remarkably more than 130 times (0.318 μm) with an obvious increase of Brunauer–Emmet–Teller (BET) surface area after treating the OPA with 3M NaOH, followed by ultrasonication for 30 min. The changes in particle size and surface morphology were investigated using transmission electron microscopy and scanning electron microscopy. Moreover, the chemical functional groups of the untreated and treated OPA showed different patterns of infrared spectra by the presence of sodium carbonate species owing to the effect of NaOH treatment. The incorporation of both untreated and treated OPA in natural rubber by increasing their loading can improve cure characteristics (i.e., reducing optimum cure time and increasing torques) and cure kinetic parameters (i.e., increasing the rate of cure and reducing activation energy). Nevertheless, the strength, degree of reinforcement, and thermal stability of treated OPA as well as wettability between treated OPA particles and NR were greater than that resulting from the untreated OPA.

Structural, Optical and Magnetic Properties of Ni Doped ZnS Nanoparticles

2018 ◽  
Vol 24 (8) ◽  
pp. 5640-5644
Author(s):  
B Sreenivasulu ◽  
S. Venkatramana Reddy ◽  
P. Venkateswara Reddy
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Absorption Spectra ◽  
Spherical Surface ◽  
Room Temperature Ferromagnetism ◽  
Average Particle Size ◽  
Precipitation Method ◽  
Chemical Compositions ◽  
Average Particle ◽  
X Ray

Pure ZnS and 3 mol% of Ni doped ZnS nano powders are prepared by chemical co-precipitation method. Properties of ZnS: Ni2+ nanoparticles are studied by X-ray diffraction Spectra (XRD), Raman spectroscopy (RS), Photoluminescence (PL), Absorption Spectra, Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDAX), Transmission electron microscopy (TEM) and Vibrating sample magnetometer (VSM). From XRD data, it conform the structure of ZnS, and particle size of pure and Ni doped ZnS data indicates the incorporation of Ni2+ in ZnS nanocrystal lattice. Raman spectra for pure and Ni doped samples exhibited vibrational modes confirm the structure of ZnS. Photoluminescence spectra reveal that the emission peaks are in UV and visible regions; this is confirming the absorption spectra. SEM micrographs show spherical morphology, and chemical compositions of samples are in stoichiometric proportions. TEM micro graphs show the spherical surface morphology and average particle size for pure and Ni2+ doped nanoparticles are in the range of 2–3 nm, this is good agreement with XRD results. M–H curves from VSM show room temperature ferromagnetism.

scholarly journals Self-Assembly Preparation of Nano-Lignin/Cationic Polyacrylamide Complexes

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1726
Author(s):  
Guoyu Tian ◽  
Xiuhong Zhong ◽  
Xuehai Wu ◽  
Zhaojiang Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Light Scattering ◽  
Self Assembly ◽  
Average Particle Size ◽  
Average Particle ◽  
Nano Particle ◽  
Enhanced Fluorescence ◽  
Scanning Electron

The present work describes the preparation of nano-lignin particles from calcium lignosulfonate (CL). The nano-lignin was fabricated from colloidal lignin–polyacrylamide complexes via self-assembly. The sizes of the nano-lignin particles were examined by dynamic light scattering (DLS) and scanning electron microscopy (SEM). The results indicated that the average particle size of the prepared nano-lignin was approximately 100 nm. In addition, the obtained nano-lignin exhibited enhanced fluorescence intensity when compared with the original lignin, which might represent a potential application of this nano-particle product.

scholarly journals Effective Method for Obtaining the Hydrosols of Detonation Nanodiamond with Particle Size < 4 nm

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1285 ◽  
Author(s):  
Andrei Trofimuk ◽  
Diana Muravijova ◽  
Demid Kirilenko ◽  
Aleksandr Shvidchenko
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Synthetic Diamond ◽  
Average Particle Size ◽  
Average Particle ◽  
Detonation Nanodiamond ◽  
New Approach ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

Detonation nanodiamond is a commercially available synthetic diamond that is obtained from the carbon of explosives. It is known that the average particle size of detonation nanodiamond is 4–6 nm. However, it is possible to separate smaller particles. Here we suggest a new approach for the effective separation of detonation nanodiamond particles by centrifugation of a “hydrosol/glycerol” system. The method allows for the production of the detonation nanodiamond hydrosol with a very sharp distribution in size, where more than 85% of particles have a size ranging 1–4 nm. The result is supported by transmission electron microscopy, atomic force microscopy, and dynamic light scattering.

Research on the Preparation of Cu-Ni-Al Prealloyed Powders

2013 ◽  
Vol 303-306 ◽  
pp. 2490-2494 ◽  
Author(s):  
Peng Lei ◽  
Jian Chen ◽  
Wei Li ◽  
Yan Jie Ren ◽  
Wei Qiu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Phase Composition ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Spherical Particle ◽  
Average Particle Size ◽  
Average Particle ◽  
Scanning Electron

The method of preparation of Cu-Ni-Al prealloyed powders were studied in this paper. Cu, Ni, Al were smelted at 1500°C and N2 was chosen as atomizing media to produce the Cu-Ni-Al prealloyed powders. The morphology and particle size distribution of Cu-Ni-Al prealloyed powders were analysis with Scanning electron microscopy; the phase composition of Cu-Ni-Al prealloyed powders were analysis XRD. The results show that the morphology of Cu-Ni-Al prealloyed powders are almost nearly spherical, particle size distribution is very uniform and the average particle size is 39μm. The powders are composed of Cu and AlNi phase.

Comparison of nickel oxide and palladium nanoparticle loaded on activated carbon for efficient removal of methylene blue

2014 ◽  
Vol 34 (2) ◽  
pp. 153-169 ◽  
Author(s):  
S Arabzadeh ◽  
M Ghaedi ◽  
A Ansari ◽  
F Taghizadeh ◽  
M Rajabi
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Particle Size ◽  
Activated Carbon ◽  
Nickel Oxide ◽  
High Surface ◽  
Average Particle Size ◽  
High Surface Area ◽  
Average Particle ◽  
Efficient Removal

Palladium nanoparticles (Pd-NPs) and nickel oxide nanoparticles (NiO-NPs) were synthesized and loaded on activated carbon (AC). This novel material successfully used for the removal of methylene blue (MB) dye from aqueous medium. Full characterization of both material using X-ray diffraction, transmission electron microscopy, scanning electron microscopy and Brunauer–Emmet–Teller analyses for Pd-NP show their high surface area (>1340 m2/g) and low pore size (<20 Å) and average particle size lower than 45 Å and for NiO-NP show their high surface area (>1316.1554 m2/g) and low pore size (<20 Å) and average particle size lower than 46 Å in addition to high reactive atom and presence of various functional groups. These unique properties make them possible for efficient removal of MB. In batch experimental set-up, optimum conditions for maximum removal of MB by both adsorbents were attained following searching effect of variables such as central composite design. The Langmuir isotherm was found to be highly recommended for fitting the experimental equilibrium data. The kinetic of adsorption of MB on both adsorbents strongly can be fitted by a combination of pseudo-second order and intraparticle diffusion pathway. The experimental result achieved in this article shows the superiority of Pd-NP-AC for MB removal than NiO-NP-AC, so the maximum adsorption capacities of Pd-NP-AC and NiO-NP-AC were 555.5 mg/g and 588.2 mg/g, respectively.

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