Silica/GO hybrids reinforced NR: Better interface interaction and dynamic behavior

2019 ◽  
Vol 52 (7) ◽  
pp. 575-592
Author(s):  
Kaikai Liu ◽  
Yuanyuan Shang ◽  
Liu Yang ◽  
Aihua Du
Keyword(s):  
Mechanical Performance ◽  
Volume Fraction ◽  
High Volume ◽  
Interfacial Interaction ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Interface Interaction ◽  
Transmission Electron ◽  
Strong Interfacial Interaction ◽  
Filler Dispersion

With silica firstly modified by 3-aminopropyl-triethoxysilane (APES), graphene oxide (GO) was prepared by modified Hummer’s method. APES-silica/GO (AsGO) hybrids were fabricated through hydrogen bond to reduce the polarity of silica and GO and increase the compatibility between natural rubber (NR) and AsGO. Subsequently, AsGO was incorporated into NR latex. The interaction between GO and silica in AsGO was characterized by X-ray diffraction, Raman, and Zeta potential. It was confirmed by transmission electron microscopy that the silica was uniformly dispersed on the surface of the GO. The filler–rubber interfacial interaction was thoroughly investigated. The amount of constrained region was quantified through differential scanning calorimetry results, and it showed that the high volume fraction of constrained region is responsible for the strong interfacial interaction. Besides, the mechanical performance, dynamic property, and electrical and thermal conductivity of NR-AsG x were studied. The results showed that the overall performance of NR-AsG x has an optimum value when the GO loading is 1.5 phr, which is due to the good filler dispersion and strong interface interaction.

Preparation and Property of Al87Ce3Ni8.5Mn1.5 Nanophase Amorphous Composites

2011 ◽  
Vol 412 ◽  
pp. 263-266
Author(s):  
Hong Wei Zhang ◽  
Li Li Zhang ◽  
Feng Rui Zhai ◽  
Jia Jin Tian ◽  
Can Bang Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Phase ◽  
Volume Fraction ◽  
Material Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Different Temperatures

The higher mechanical strength of Al87Ce3Ni8.5Mn1.5 nanophase amorphous composites has been obtained with two methods. The first nanophase amorphous composites are directly produced by the single roller spin quenching technology. The method taken for the second nanophase amorphous composites is at first to obtain amorphous single-phase alloy, followed by annealed at different temperatures .The formative condition, the microstructure, the particle size, the volume fraction of α-Al phase and microhardness of nanophase amorphous composites etc have been investigated and compared by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The microstructure of composites produced by the second method is higher than the former, the fabricated material structure of the system is more uniform and the process is easier to control.

Hardness evolution of Al–Cr–N coatings under thermal load

2008 ◽  
Vol 23 (11) ◽  
pp. 2880-2885 ◽  
Author(s):  
Herbert Willmann ◽  
Paul H. Mayrhofer ◽  
Lars Hultman ◽  
Christian Mitterer
Keyword(s):  
Thermal Load ◽  
Structural Changes ◽  
Single Phase ◽  
Volume Fraction ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Al Content ◽  
Annealing Temperatures ◽  
Transmission Electron

Microstructure and hardness evolution of arc-evaporated single-phase cubic Al0.56Cr0.44N and Al0.68Cr0.32N coatings have been investigated after thermal treatment in Ar atmosphere. Based on a combination of differential scanning calorimetry and x-ray diffraction studies, we can conclude that Al0.56Cr0.44N undergoes only small structural changes without any decomposition for annealing temperatures Ta ⩽ 900 °C. Consequently, the hardness decreases only marginally from the as-deposited value of 30.0 ± 1.1 GPa to 29.4 ± 0.9 GPa with Ta increasing to 900 °C, respectively. The film with higher Al content (Al0.68Cr0.32N) exhibits formation of hexagonal (h) AlN at Ta ⩾ 700 °C, which occurs preferably at grain boundaries as identified by analytical transmission electron microscopy. Hence, the hardness increases from the as-deposited value of 30.1 ± 1.3 GPa to 31.6 ± 1.4 GPa with Ta = 725 °C. At higher temperatures, where the size and volume fraction of the h-AlN phase increases, the hardness decreases to 27.5 ± 1.0 GPa with Ta = 900 °C.

Synthesis of nanostructured metal (Fe, Al)-C60 composites

2010 ◽  
Vol 1276 ◽  
Author(s):  
I. I. Santana García ◽  
V. Garibay Febles ◽  
H. A. Calderon
Keyword(s):  
Raman Spectroscopy ◽  
Mechanical Milling ◽  
Volume Fraction ◽  
High Volume ◽  
X Ray Diffraction ◽  
Nanostructured Composite ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Show Evidence ◽  
Spark Plasma

AbstractComposites of M-2.5 mol. % Fullerene C60 composites (where M= Fe or Al) are prepared by mechanical milling and Spark Plasma Sintering (SPS). The SPS technique has been used to consolidate the resulting powders and preserve the massive nanostructure. Results of X-Ray Diffraction and Raman Spectroscopy show that larger milling balls (9.6 mm in diameter) produce transformation of the fullerene phase during mechanical milling. Alternatively smaller milling balls (4.9 mm in diameter) allow retention of the fullerene phase. SEM shows homogeneous powders with different particle sizes depending on milling times. Sintering produces nanostructured composite materials with different reinforcing phases including C60 fullerenes, diamonds and metal carbides. The presence of each phase depends characteristically on the energy input during milling. Transmission Electron Microscopy (TEM) and Raman Spectroscopy show evidence of the spatial distribution and nature of phases. Diamonds and carbides can be identified for the sintered Fe containing composites with a relatively high volume fraction.

scholarly journals PEEK filament characteristics before and after extrusion within fused filament fabrication process

2022 ◽  
Author(s):  
Cleiton André Comelli ◽  
Richard Davies ◽  
HenkJan van der Pol ◽  
Oana Ghita
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Extrusion Process ◽  
X Ray Diffraction ◽  
Fused Filament Fabrication ◽  
Scanning Calorimetry ◽  
Fast Scanning Calorimetry ◽  
Transmission Electron ◽  
Before And After ◽  
History Of

AbstractThe heating and extrusion process in fused filament fabrication (FFF) is significantly shorter than the conventional extrusion process where longer heating times and significant pressure are applied. For this reason, it is important to understand whether the crystal history of the feedstock is fully erased through the FFF process and whether the FFF process can be tailored further by engineering the crystallization of the feedstock filaments. In this context, a methodology for evaluating the influence of morphology and mechanical properties on different feedstock and extruded filaments is proposed. Filaments with three different PEEK 450G crystalline structures (standard crystallinity, drawn filament and amorphous filament) were selected and evaluated, before and after free extrusion. The resulting morphology, crystallinity and mechanical properties of the extruded filaments were compared against the feedstock properties. X-ray diffraction (XRD), transmission electron microscopy (TEM), differential and fast scanning calorimetry (DSC/FDSC) and tensile test were the techniques used to evaluate the materials. The results showed clear differences in the properties of the feedstock materials, while the analysis of the extruded filaments points to a homogenization of the resulting material producing mostly similar mechanical properties. However, the use of the drawn filament highlighted a statistically significant improvement in crystallinity and mechanical performance, especially in strain values. This conclusion suggests the innovative possibility of improving the quality of manufactured parts by tailoring the microstructure of the feedstock material used in the FFF process. Graphical abstract

Deformation Behavior of Bulk Amorphous Zr-Base Alloys

1998 ◽  
Vol 554 ◽  
Author(s):  
A. Leonhard ◽  
M. Heilmaier ◽  
J. Eckert ◽  
L. Schultz
Keyword(s):  
Room Temperature ◽  
Small Volume ◽  
Volume Fraction ◽  
High Volume ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
Ni Alloys ◽  
Young’S Moduli ◽  
Transmission Electron ◽  
Complex Parts

AbstractBulk Zr-Al-Cu-Ni alloys were produced by die casting into a copper mold under Aratmosphere. The microstructure of fully amorphous as well as partially crystalline samples was analyzed by X-ray diffraction (XRD), scanning (SEM) and transmission electron microscopy (TEM), and chemical analysis with special emphasis on the size and composition of the crystallites. The mechanical behavior of the different samples was investigated by constant compression rate tests. At room temperature the samples show inhomogeneous deformation and, independent of the chosen composition, relatively low Young's moduli of about 70 GPa, flow stresses around 2 GPa and elastic strains of up to 3 %. Fully amorphous samples show microplasticity of up to 2 % strain without significant work hardening while specimens with a fairly high volume fraction of crystalline phases are extremely brittle. In contrast, at high temperatures around the glass transition temperature T8 both amorphous and partially crystalline specimens exhibit at low strain rates homogeneous deformation with an initial stress overshoot followed by an extended region of plastic flow. As compared to room temperature, the peak stresses are much lower and are hardly influenced by the presence of small volume fractions of crystalline phases. The observed thermal stability against crystallization provides a promising possibility for easy shaping of complex parts at temperatures around Tg.

scholarly journals Characterization of γ′ Precipitates in Cast Ni-Based Superalloy and Their Behaviour at High-Homologous Temperatures Studied by TEM and in Situ XRD

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2397 ◽  
Author(s):  
Łukasz Rakoczy ◽  
Ondrej Milkovič ◽  
Bogdan Rutkowski ◽  
Rafał Cygan ◽  
Małgorzata Grudzień-Rakoczy ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Matrix Material ◽  
High Volume ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
In Situ Xrd ◽  
Transmission Electron ◽  
The Matrix

In situ X-ray diffraction and transmission electron microscopy has been used to investigate René 108 Ni-based superalloy after short-term annealing at high-homologous temperatures. Current work is focused on characterisation of γ′ precipitates, their volume fraction, evolution of the lattice parameter of γ and γ′ phases and misfit parameter of γ′ in the matrix. Material in the initial condition is characterised by a high-volume fraction (over 63%) of γ′ precipitates. Irregular distribution of alloying elements was observed. Matrix channels were strongly enriched in Cr, Co, W and Mo, whereas precipitates contain large amount of Al, Ti, Ta and Hf. Exposure to high-homologous temperatures in the range 1100–1250 °C led to the dissolution of the precipitates, which influenced the change of lattice parameter of both γ and γ′ phases. The lattice parameter of the matrix continuously grew during holding at high temperatures, which had a dominant influence on the more negative misfit coefficient.

scholarly journals Effects of Sintering Temperature on Densification, Microstructure and Mechanical Properties of Al-Based Alloy by High-Velocity Compaction

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Xianjie Yuan ◽  
Xuanhui Qu ◽  
Haiqing Yin ◽  
Zaiqiang Feng ◽  
Mingqi Tang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Velocity ◽  
Sintered Density ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
High Velocity Compaction ◽  
Sintered Temperature

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.

scholarly journals Preparation, characterization and scale-up of sesamol loaded solid lipid nanoparticles

2012 ◽  
Vol 2 (1) ◽  
pp. 8 ◽  
Author(s):  
Vandita Kakkar ◽  
Indu Pal Kaur
Keyword(s):  
Solid Lipid Nanoparticles ◽  
Scale Up ◽  
Spherical Shape ◽  
Entrapment Efficiency ◽  
Lipid Nanoparticles ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Solid Lipid ◽  
Transmission Electron ◽  
The Brain

Sesamol loaded solid lipid nanoparticles (SSLNs) were prepared with the aim of minimizing its distribution to tissues and achieving its targeting to the brain. Three scale-up batches (100x1 L) of S-SLNs were prepared using a microemulsification technique and all parameters were statistically compared with the small batch (1x;10 mL). S-SLNs with a particle size of less than 106 nm with a spherical shape (transmission electron microscopy) were successfully prepared with a total drug content and entrapment efficiency of 94.26±2.71% and 72.57±5.20%, respectively. Differential scanning calorimetry and infrared spectroscopy confirmed the formation of lipidic nanoparticles while powder X-ray diffraction revealed their amorphous profile. S-SLNs were found to be stable for three months at 5±3°C in accordance with International Conference on Harmonisation guidelines. The SLN preparation process was successfully scaled-up to a 100x batch on a laboratory scale. The procedure was easy to perform and allowed reproducible SLN dispersions to be obtained.

Insight into the Formation of Ultrafine Nanostructures in Bulk Amorphous Zr54.5 Ti7.5Al10Cu20Ni8

2001 ◽  
Vol 703 ◽  
Author(s):  
André Heinemann ◽  
Helmut Hermann ◽  
Albrecht Wiedenmann ◽  
Norbert Mattern ◽  
Uta Kühn ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Volume Fraction ◽  
High Volume ◽  
High Resolution Electron Microscopy ◽  
Scattering Data ◽  
Scanning Calorimetry ◽  
Enhanced Diffusion ◽  
Resolution Electron ◽  
The Mean ◽  
Interparticle Interference

ABSTRACTBulk amorphous Zr54.5 Ti7.5Al10Cu20Ni8 is investigated by means of smal-angle neutron scattering (SANS), differential-scanning calorimetry (DSC), high-resolution electron microscopy (HREM) and other methods. The formation of ultrafine nanostructures in the glassy phase is observed and explained by a new model. Structura fluctuations of randomly distributed partialy ordered domains grow during annealing just below the glass transition temperature by local re-ordering. During anneaing the DSC gives evidence for a increasing volume fraction of the localy ordered domains. At high volume fractions of impinging domains a percolation threshold on the interconnected domain boundaries occurs and enhanced diffusion becomes possible. At that stage SANS measurements lead to satistically significant scattering data. The SANS signals are anayzed in terms of a model taking into account spherica particles surrounded by diffusion zones and interparticle interference effects. The mean radius of the nanocrystaline particles is determined to 1 nm and the mean thickness of the depletion zone is 2 nm. The upper limit for the volume fraction after annealing at 653 K for 4hours is about 20 %. Electron microscopy confirms the size and shows that the particle are crystaline.

scholarly journals Role of Surfactants in the Properties of Poly(Ethylene Terephthalate)/Purified Clay Nanocomposites

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1397 ◽  
Author(s):  
Elaine dos Santos ◽  
Marcus Fook ◽  
Oscar Malta ◽  
Suédina de Lima Silva ◽  
Itamara Leite
Keyword(s):  
Clay Nanocomposites ◽  
Phosphonium Salts ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Alkyl Ammonium ◽  
Pet Crystallization

Purified clay was modified with different amounts of alkyl ammonium and phosphonium salts and used as filler in the preparation of PET nanocomposites via melt intercalation. The effect of this type of filler on morphology and thermal and mechanical properties of PET nanocomposites was investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analyses (TG), tensile properties, and transmission electron microscopy (TEM). The results showed that the mixture of alkyl ammonium and phosphonium salts favored the production of PET nanocomposites with intercalated and partially exfoliated morphologies with slight improvement in thermal stability. In addition, the incorporation of these organoclays tended to inhibit PET crystallization behavior, which is profitable in the production of transparent bottles.

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