TEM and DSC Studies on the Synthetic Diamond Grown from Fe-Ni-C-B System under HPHT

2011 ◽  
Vol 320 ◽  
pp. 3-7
Author(s):  
Jian Hong Gong ◽  
Shu Xia Lin ◽  
Jun Gao
Keyword(s):  
Thermal Stability ◽  
Boron Content ◽  
Synthetic Diamond ◽  
Scanning Calorimetry ◽  
Dsc Studies ◽  
Diamond Crystals ◽  
Transmission Electron ◽  
High Pressure High Temperature ◽  
Alloy Catalysts ◽  
Thermal Stability Of

Transmission Electron Microscope (TEM) and Different Scanning Calorimetry (DSC) Methods Were Used to Investigate the Diamonds Grown with Different Boron Content Alloy Catalysts under High-Pressure High-Temperature (HPHT). Experimental Results Demonstrated the Microstructure and Composition of Boride Compounds in Synthetic Diamond, such as (FeNi)23(CB)6 ,(Fe, Ni)3(C,B), (Fe,Ni)B and B4C, Whose Formation Process Was Analyzed. the Thermal Stability of Diamond Depends on Boron Concentration in Catalyst According to DSC Studies. we Analyzed the Reason of Diamond Oxidation.The Work Offers Valuable Information for Improving the Thermal Stability of Synthetic Diamond Crystals by Adjusting Boron Content in the Fe-Ni Based Catalyst.

scholarly journals The Effect of Ultrasonic Treatment on Thermal Stability of the Cured Epoxy/Layered Silicate Nanocomposite

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
N. Y. Yuhana ◽  
S. Ahmad ◽  
A. R. Shamsul Bahri
Keyword(s):  
Thermal Stability ◽  
Ultrasonic Treatment ◽  
Binary Systems ◽  
Layered Silicate ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Mechanical Stirring ◽  
Transmission Electron ◽  
Cloisite 30B ◽  
Thermal Stability Of

The effect of ultrasonic treatment on thermal stability of binary systems containing epoxy and organic chemically modified montmorillonite (Cloisite 30B) was studied. Differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), and wide angle X-ray diffraction (WAXD) analysis were utilized. The mixing of epoxy and Cloisite 30B nanocomposites was performed by mechanical stirring, followed by 1 or 3-hour ultrasonic treatment, and polyetheramine as the curing agent. Both XRD and TEM analyses confirmed that the intercalation of Cloisite 30B was achieved. Thed0spacings for silicate in cured sample prepared at 1- and 3-hour duration of ultrasonic treatment were about 21 and 18 Å, respectively. This shows that shorter duration or ultrasonic treatment may be preferable to achieve higherd0spacing of clay. This may be attributed to the increase in viscosity as homopolymerization process occurred, which restricts silicate dispersion. The 1-hour sonicated samples seem to be more thermally stable during the glass transition, but less stable during thermal decomposition process.

Effects of Alloy Compositions on Amorphization and Crystallization of Al-Ni-Ce-C Powders by Mechanical Alloying

2011 ◽  
Vol 66-68 ◽  
pp. 2109-2116
Author(s):  
Jun Hua Chen ◽  
Song Zhang ◽  
Ying Jie Qu
Keyword(s):  
Thermal Stability ◽  
Ball Milling ◽  
Great Influence ◽  
High Energy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Amorphous Powders ◽  
Ball Milling Technique ◽  
Thermal Stability Of

In the present work, Al-Ni-Ce-C amorphous powders with different compositions have been prepared by a high energy ball milling technique. The amorphization behaviors of the Al-Ni-Ce-C powders have been studied using X-ray diffraction and transmission electron microscopy. The results show that alloy compositions have a great influence on the amorphization behavior of the Al-Ni-Ce-C powders and the optimum composition is Al85Ni10Ce5+1 wt.% C for the formation of amorphous phase. The thermal stability of the as-milled powders has been investigated by differential scanning calorimetry. It has been found that the compositional effects on thermal stability are similar to those on the amorphization of Al-Ni-Ce-C. In addition, the more addition of carbon decreases both glass forming ability and thermal stability of the Al-Ni-Ce-C system under ball milling conditions. Furthermore, comparison has been carried out between Al85Ni10Ce5+1 wt.% C amorphous powders and Al85Ni10Ce5glassy ribbons with respect to thermal stability.

Thermal Stability of Vacuum Hot Pressed Bulk Nanostructured Al-Cu Alloys

2011 ◽  
Vol 690 ◽  
pp. 234-237 ◽  
Author(s):  
Thangaraju Shanmugasundaram ◽  
Martin Heilmaier ◽  
V. Subramanya Sarma ◽  
B.S Murty
Keyword(s):  
Thermal Stability ◽  
Grain Growth ◽  
High Energy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Grain Sizes ◽  
Cu Alloys ◽  
Transmission Electron ◽  
Energy Ball ◽  
Thermal Stability Of

Bulk nanostructured Al-4Cu alloy was synthesized by high energy ball milling followed by vacuum hot pressing. Its thermal stability was investigated up to 450°C using differential scanning calorimetry, X-ray diffraction, and transmission electron microscopy. The results showed that grain growth in this Al-4Cu alloy was very limited and grain sizes in the range of 100 nm were still present in the alloys after exposure to 450 °C corresponding to a temperature as high as 0.77 T/Tm. The TEM investigations reveal that such a high thermal stability against grain growth observed in this alloy is attributed to the presence of ultrafine dispersoids.

Thermal stability of CaCO3/polyethylene (PE) nanocomposites

2019 ◽  
Vol 27 (7) ◽  
pp. 371-382
Author(s):  
S Sahebian ◽  
MT Hamed Mosavian
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Thermal Stability ◽  
Morphological Structure ◽  
Thermomechanical Analysis ◽  
Scanning Calorimetry ◽  
Weight Percentage ◽  
Transmission Electron ◽  
Crystallization Experiments ◽  
Thermal Stability Of

Calcium carbonate (CaCO3) nanoparticles in polymer matrix cause to improvement in polymer performance, including thermal stability and mechanical properties. The main goal of this article is to investigate the effect of different weight percentage of nanoparticles of CaCO3 on thermal stability and mechanical properties of polyethylene (PE) nanocomposites. The morphological structure of CaCO3 nanoparticles and nanocomposites was investigated by transmission electron microscopy and scanning electron microscopy. The thermal stability of PE and its nanocomposites was also determined by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and thermomechanical analysis. Nonisothermal crystallization experiments by DSC test showed that the incorporation of nanoparticles increased the crystallinity, glass transition temperature, and the effective energy barrier for crystallization process. Besides, degradation behavior was evaluated by TGA. The onset mass loss temperature shifted to higher value in the presence of nanoparticles.

scholarly journals Thermal treatment of magnetite nanoparticles

2015 ◽  
Vol 6 ◽  
pp. 1385-1396 ◽  
Author(s):  
Beata Kalska-Szostko ◽  
Urszula Wykowska ◽  
Dariusz Satula ◽  
Per Nordblad
Keyword(s):  
Thermal Stability ◽  
Thermal Treatment ◽  
Magnetite Nanoparticles ◽  
Surface Characteristics ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Before And After ◽  
Thermal Stability Of

This paper presents the results of a thermal treatment process for magnetite nanoparticles in the temperature range of 50–500 °C. The tested magnetite nanoparticles were synthesized using three different methods that resulted in nanoparticles with different surface characteristics and crystallinity, which in turn, was reflected in their thermal durability. The particles were obtained by coprecipitation from Fe chlorides and decomposition of an Fe(acac)3 complex with and without a core–shell structure. Three types of ferrite nanoparticles were produced and their thermal stability properties were compared. In this study, two sets of unmodified magnetite nanoparticles were used where crystallinity was as determinant of the series. For the third type of particles, a Ag shell was added. By comparing the coated and uncoated particles, the influence of the metallic layer on the thermal stability of the nanoparticles was tested. Before and after heat treatment, the nanoparticles were examined using transmission electron microscopy, IR spectroscopy, differential scanning calorimetry, X-ray diffraction and Mössbauer spectroscopy. Based on the obtained results, it was observed that the fabrication methods determine, to some extent, the sensitivity of the nanoparticles to external factors.

Thermal Stability of N-Heterocycle-Stabilized Iodanes – A Systematic Investigation

2019 ◽  
Author(s):  
Andreas Boelke ◽  
Yulia A. Vlasenko ◽  
Mekhman S. Yusubov ◽  
Boris Nachtsheim ◽  
Pavel Postnikov
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Systematic Investigation ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

<p>The thermal stability of pseudocyclic and cyclic <i>N</i>-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l<sup>3</sup>-iodanes (NHIs) through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is investigated. NHIs bearing <i>N</i>-heterocycles with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal stability with reactivity in a model oxygenation. </p>

scholarly journals Isothermal Vulcanization and Non-Isothermal Degradation Kinetics of XNBR/Epoxy/XNBR-g-Halloysite Nanotubes (HNT) Nanocomposites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2872
Author(s):  
Seyed Mohamad Reza Paran ◽  
Ghasem Naderi ◽  
Elnaz Movahedifar ◽  
Maryam Jouyandeh ◽  
Krzysztof Formela ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Degradation Kinetics ◽  
Halloysite Nanotubes ◽  
Butadiene Rubber ◽  
Order Model ◽  
Scanning Calorimetry ◽  
Theoretical Methods ◽  
Vulcanization Kinetics ◽  
Kinetics Of ◽  
Thermal Stability Of

The effect of several concentrations of carboxylated nitrile butadiene rubber (XNBR) functionalized halloysite nanotubes (XHNTs) on the vulcanization and degradation kinetics of XNBR/epoxy compounds were evaluated using experimental and theoretical methods. The isothermal vulcanization kinetics were studied at various temperatures by rheometry and differential scanning calorimetry (DSC). The results obtained indicated that the nth order model could not accurately predict the curing performance. However, the autocatalytic approach can be used to estimate the vulcanization reaction mechanism of XNBR/epoxy/XHNTs nanocomposites. The kinetic parameters related to the degradation of XNBR/epoxy/XHNTs nanocomposites were also assessed using thermogravimetric analysis (TGA). TGA measurements suggested that the grafted nanotubes strongly enhanced the thermal stability of the nanocomposite.

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