Tuning the Ablation, Thermal and Mechanical Characteristics of Phenolic Resin Reinforced EPDM Ultra-High Temperature Insulation

2021 ◽  
Vol 875 ◽  
pp. 88-95
Author(s):  
Sadia Sagar Iqbal ◽  
Tasawer Shahzad Ahmad ◽  
Arshad Bashir ◽  
Ali Bahadar ◽  
Farzana Siddique
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Scanning Electron Microscopy ◽  
Mechanical Characteristics ◽  
Phenolic Resin ◽  
Ethylene Propylene Diene Monomer ◽  
Polymer Melting ◽  
Base Matrix ◽  
Ablation Characteristics ◽  
Scanning Electron

The present research reports the influences of variant phenolic resin concentrations on the thermo-mechanical and ablation characteristics of ethylene propylene diene monomer (EPDM) elastomer. Backface temperature acclivity (BTA), charring rates, and insulation indexes were executed for the fabricated composite specimens. It was noticed that BTA was enhanced while linear/radial/mass ablation rates were significantly diminished with increasing concentration of phenolic resin (PR) in base matrix (elastomeric polymer). The composite (30wt%PR/EPDM) has 25% high thermal endurance compared to virgin EPDM composite. Thermal conductivity was increased with increasing PR to EPDM ratio. PR incorporation has remarkably enhanced the ultimate tensile strength of the EPDM elastomer. An efficient improvement in elastomeric hardness was also observed with increasing PR contents in EPDM matrix. Scanning Electron Microscopy (SEM) results showed the porosity generation and polymer melting during ablation.

USE OF NANOFLUIDS BASED ON CARBON NANOPARTICLES TO DISPLACE OIL FROM THE POROUS MEDIUM MODEL

2020 ◽  
Vol 6 (4) ◽  
pp. 141-157
Author(s):  
Yuri V. Pakharukov ◽  
Farid K. Shabiev ◽  
Ruslan F. Safargaliev ◽  
Boris S. Yezdin ◽  
Valery V. Kalyada
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Porous Medium ◽  
Synergistic Effect ◽  
Transition Region ◽  
Dimensional Structure ◽  
Hybrid Nanofluids ◽  
Scanning Electron

Graphene, due to its two-dimensional structure, has some unique properties. For example, the thermal conductivity and electrical conductivity of graphene are an order of magnitude higher than the thermal conductivity and electrical conductivity of copper. For this reason, graphene-based nanofluids are now used in many industries. Due to the effect of self-organization of graphene nanoparticles with hydrocarbon molecules, the use of graphene has become possible in the oil industry. Graphene-based nanofluids are used as a displacement fluid to increase the oil recovery coefficient. The displacing ability of graphene-based nanofluids is concentration dependent. An increase in the concentration of nanoparticles entails an increase in viscosity, which negatively affects the performance characteristics of the nanofluid. This problem is partially solved due to the synergistic effect, hybrid nanofluids consisting of nanoparticles of graphene and metals or carbides enhance the displacing ability. Using atomic force microscopy, scanning electron microscopy and molecular modelling methods, this work has studied the formation of supramolecular structures that form a transition region at the oil-nanofluid interface with low surface tension as a result of a synergistic effect in the interaction of graphene planar nanoparticles and silicon carbide nanoparticles covered with graphene layers (Core-shell). The model experiments on a Hele-Shaw cell have shown that in a porous medium, such hybrid nanofluids have a high displacement ability of residual oil. At the same time, the oil — nanofluid interface remains stable, without the formation of viscous fingers. During the study by scanning electron microscopy, a transition region was observed, in the structuring of which the nanoparticles were directly involved. The displacement efficiency of a hybrid nonofluid depends on the concentration of nanoparticles and their interaction.

Influence of stack sequence on the mechanical characteristics of hybrid composites analyzed using cone beam computed tomography and scanning electron microscopy

2020 ◽  
Vol 41 (12) ◽  
pp. 5059-5071
Author(s):  
Srinivas Shenoy Heckadka ◽  
Raghuvir Pai Ballambat ◽  
Vijay Kini Manjeshwar ◽  
Mathangi Kumar ◽  
Pranav Hegde ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Computed Tomography ◽  
Scanning Electron Microscopy ◽  
Cone Beam Computed Tomography ◽  
Mechanical Characteristics ◽  
Hybrid Composites ◽  
Cone Beam ◽  
Scanning Electron

Thermal Conductivity of Boron Carbides

1987 ◽  
Vol 97 ◽  
Author(s):  
Marvin Moss
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Temperature Dependence ◽  
Rutherford Backscattering ◽  
Rutherford Backscattering Spectroscopy ◽  
Theoretical Density ◽  
Increasing Temperature ◽  
Scanning Electron

ABSTRACTThe thermal conductivity, k, of boron carbides of various B/C ratios, two modes of preparation – hot pressed and carbothermic, and two isotopic variants of boron – 11B and normal boron 10.81B, was measured from 300 to 1023 K. The density and composition of the samples were reflected in the magnitude and temperature dependence of k, and were investigated further with scanning electron microscopy, Rutherford backscattering spectroscopy, and Raman spectroscopy. While lower than theoretical density in B4C reduces k, the characteristic monotonic decline of k with increasing temperature is retained. This k-vs.-T behavior distinguishes B4C from material with larger B/C ratios for which the temperature dependence is essentially nil.

Interfacial Examination of Cu/Al Joints Using Ultrafine Al-Si Powder as Brazing Filler Metal

2013 ◽  
Vol 829 ◽  
pp. 52-56
Author(s):  
Maryam Yarveicy ◽  
Ali Mohammad Hadian
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectrometry ◽  
Filler Metal ◽  
Inert Atmosphere ◽  
Lower Weight ◽  
Prismatic Structure ◽  
Layer Region ◽  
Scanning Electron

Al-Cu joints have been widely used in electronic and heat exchanger industries due to their excellent electrical and thermal conductivity. Meanwhile, the use of Al in the Al-Cu joints can result in lower weight and cost of the final structure. The purpose of the current study is to join Al to Cu by furnace brazing using ultrafine Al-Si powder. To study the microstructure of the join area, the brazing tests were conducted in the range of 590 to 610°C for 5 to 15 minutes under inert atmosphere. The microstructure of Al/Cu joints was studied by scanning electron microscopy (SEM). The elemental analysis was conducted using an energy dispersive spectrometry (EDS) system. Experimental results show that two kinds of intermetallic compounds (IMCs) mainly Cu3Al2 and CuAl2 phases are formed near the interface of copper and in the braze layer region. The bulky prismatic structure which is formed on the side of Al substrate was found to be α-Al+CuAl2 eutectic.

Effect of the Consolidation Technique on the Sintering Ability and Thermal Properties of AlN Processed from Aqueous Suspensions

2006 ◽  
Vol 514-516 ◽  
pp. 1531-1535
Author(s):  
Susana M.H. Olhero ◽  
José Maria F. Ferreira
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Scanning Electron Microscopy ◽  
Slip Casting ◽  
Inert Atmosphere ◽  
Sintering Aids ◽  
X Ray ◽  
Aqueous Suspensions ◽  
Dry Pressing ◽  
Scanning Electron

In this work, two different consolidation techniques were used to obtain AlN samples: slip casting and dry pressing of granules obtained from aqueous suspensions by freeze granulation. The green samples were sintered at a temperature (1750°C) lower than those usually used (>1800°C), using CaF2 and YF3 as sintering aids. The microstructural features were analysed by scanning electron microscopy (SEM) and the crystalline phases formed were identified by X-ray (XRD). Full dense AlN-based ceramics were obtained from both consolidation techniques; however the thermal conductivity values were quite different. The presence of carbon in the samples derived from the freeze granulated powder containing organic processing additives de-waxed in an inert atmosphere revealed to be helpful in the cleaning of oxygen present at the grain boundaries and consequently, for enhancing the thermal conductivity.

scholarly journals Thermal Conductivity of Polyimide/Carbon Nanofiller Blends

2007 ◽  
Vol 334-335 ◽  
pp. 749-752 ◽  
Author(s):  
Subrata Ghose ◽  
K.A. Watson ◽  
D.M. Delozier ◽  
D.C. Working ◽  
John W. Connell ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Tensile Testing ◽  
Expanded Graphite ◽  
Multiwalled Carbon ◽  
Carbon Nanofiller ◽  
Scanning Electron

In efforts to improve the thermal conductivity (TC) of Ultem™ 1000, it was compounded with three carbon based nano-fillers. Multiwalled carbon nanotubes (MWCNT), vapor grown carbon nanofibers (CNF) and expanded graphite (EG) were investigated. Ribbons were extruded to form samples in which the nano-fillers were aligned. Samples were fabricated by compression molding where the nano-fillers were randomly oriented. The thermal properties were evaluated by DSC and TGA, and the mechanical properties of the aligned samples were determined by tensile testing. The degree of dispersion and alignment of the nanoparticles were investigated with high-resolution scanning electron microscopy. The thermal conductivity was measured in two directions using the Nanoflash technique.

Low Thermal Conductivity Ceramics for Thermal Barrier Coatings

2007 ◽  
Vol 336-338 ◽  
pp. 1764-1766 ◽  
Author(s):  
Ye Xia Qin ◽  
Jing Dong Wang ◽  
Wei Pan ◽  
Chun Lei Wan ◽  
Zhi Xue Qu
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Scanning Electron Microscopy ◽  
Rare Earth ◽  
Thermal Barrier Coatings ◽  
Thermal Barrier ◽  
X Ray Diffraction ◽  
Barrier Coatings ◽  
X Ray ◽  
Scanning Electron

This paper summarizes the basic properties of a series of rare-earth zirconate ceramics (Gd2Zr2O7, Sm2Zr2O7, Dy2Zr2O7, Er2Zr2O7 and Yb2Zr2O7). The phases and microstructures were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Thermal properties of these materials were determined. The results indicated that Sm2Zr2O7 rare-earth zirconate ceramics have the lower thermal conductivity and the highest thermal expansion coefficient than other rare-earth zirconate ceramics. The dielectric constant decreases with the increase of atomic number.

scholarly journals Equi-Biaxial Fatigue of Elastomers: The Effect of Oil Swelling on Fatigue Life

2008 ◽  
Vol 81 (4) ◽  
pp. 638-649 ◽  
Author(s):  
Steve Jerrams ◽  
John Hanley ◽  
Niall Murphy ◽  
Hassan Ali
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elastic Modulus ◽  
Fatigue Life ◽  
Fatigue Testing ◽  
Ethylene Propylene Diene Monomer ◽  
Stored Energy ◽  
Mineral Oils ◽  
Biaxial Fatigue ◽  
Scanning Electron

Abstract The effect of oil swelling on the fatigue life of ethylene propylene diene monomer rubber (EPDM) has been studied under conditions of equi-biaxial cycling using dynamic bubble inflation. Specimens were subjected to varying degrees of swelling in reference mineral oils and fatigued at constant engineering stress amplitudes. The reference oils used for swelling the EPDM had known aniline points, allowing the rubber-oil compatibility to be determined. The inflation fluid for fatigue testing was selected with a solubility parameter that would produce a desired level of incompatibility with the test specimens, thereby limiting the amount of additional swelling during cycling. Wöhler (S-N) plots were generated for dry and swollen specimens and the changes in complex elastic modulus E* and dynamic stored energy were analyzed. Specimen fractures were analyzed using scanning electron microscopy. The fractures in the swollen samples show that the failure surfaces flowed more readily over each other than did those of the dryer specimens.

Resistance to Tracking of EPDM Aged by Gamma Irradiation under AC and DC Voltages

2007 ◽  
Vol 8 (3) ◽  
Author(s):  
V. Rajini ◽  
K. Udayakumar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gamma Radiation ◽  
Morphological Changes ◽  
Ethylene Propylene Diene Monomer ◽  
Gamma Source ◽  
60Co Gamma ◽  
Different Doses ◽  
Scanning Electron ◽  
Sem Analyses

The present paper reports the results of a study of dielectric ageing of Ethylene Propylene Diene Monomer (EPDM) by gamma radiation. EPDM flat specimens were aged under gamma radiation with three different doses. Samples were irradiated in air up to 300 kRad with a dose rate of 51 kRad/h using a 60Co gamma source. The resistance to tracking on applying DC and AC voltage was examined. We found that the DC resistance to tracking is lower than the AC resistance. The tracking resistance under –ve DC voltages are lower than +ve DC values. With the increase in radiation dose, the DC and AC tracking resistances change in a non-linear way. The erosion depth and contact angle affected by radiation have been studied. In addition, Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) analyses were done, to analyze the morphological changes.

scholarly journals Gypsum composition with siltstone-based mineral modifier

2019 ◽  
Author(s):  
Grigory Yakovlev ◽  
Anastasiya Gordina ◽  
Vladimir Khritankov ◽  
Vadim Khozin ◽  
Arina Shaybadullina ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Sulfate ◽  
Metamorphic Rock ◽  
Mechanical Characteristics ◽  
Physicomechanical Properties ◽  
Structure And Properties ◽  
Monolithic Structure ◽  
Scanning Electron ◽  
Crystalline Hydrates

The paper presents the results of studies of the structure and properties of the gypsum composition comprising 3% of crushed siltstone, a metamorphic rock. The structure and physicochemical properties of siltstone were studied, which predetermine its usage as a structuring additive in gypsum compositions. Adding crushed siltstone to the composition of a gypsum binder is shown to cause the compaction of the structure of the gypsum matrix due to changes in the morphology of crystalline hydrates of calcium sulfate and monolithic structure in general, and, consequently, the enhanced mechanical characteristics of the gypsum composition. Using scanning electron microscopy, differential thermography, and IR spectral analysis explain the change in the physicomechanical properties of the gypsum binder.

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