scholarly journals The Microstructure and Thermal Conductivity of Pressureless InfiltratedSiCp/AlComposites Containing Electroless Nickel Platings

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Aihua Zou ◽  
Xianliang Zhou ◽  
Xiaozhen Hua ◽  
Duosheng Li ◽  
Kaiyang Wu
Keyword(s):  
Thermal Conductivity ◽  
Three Dimensional ◽  
Electroless Nickel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uniform Coating ◽  
Video Microscope ◽  
Silicon Carbide Particles ◽  
Carbide Particles ◽  
Scanning Electron

A nickel (Ni) coating was deposited on the surface of silicon carbide particles (SiCp) through electroless plating and we characterized the morphology and phase structure of the coating and the pressureless infiltratedSiCp/Alcomposites. The effect of Ni coatings on the thermal conductivity of the composites was examined and analyzed with three-dimensional video microscope, scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction microscope (XRD), and finite-element. The results show that a continuous and uniform coating with a certain thickness (around 3.5 μm) can be formed on the surface ofSiCp. With the addition of the Ni layer, there are some intermetallics Ni3Al but no interfacial carbide Al4C3, which improves the wettability and the thermal conductivity of the composites. The experiments and simulations both show that Ni coatings do not substantially decrease the overall thermal conductivity of the composite, although the thermal conductivity of Ni itself is lower than Al and SiC by a factor of 1.

scholarly journals Structural and thermoelectric properties of the Pr2Zr2O7 compound

2019 ◽  
pp. 4-9
Author(s):  
Adolfo Quiroz-Rodríguez ◽  
Cesia Guarneros-Aguilar ◽  
Ricardo Agustin-Serrano
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Crystal Size ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increasing Temperature ◽  
Thermal Stability Of ◽  
Scanning Electron

In this research, it is presented a detailed study of the structural and thermoelectric properties of the pyrochlore zirconium Pr2Zr2O7 compound prepared by solid-state reaction (SSR) in air at ambient pressure. The synthesized sample was characterized using powder X-ray diffraction. The thermal stability of the thermoelectric compound (TE) Pr2Zr2O7 was tested by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Scanning electron microscopy shows that the crystal size varies between 0.69 and 2.81μm. Electrical conductivity (\sigma) of the sample calcined at 1400 °C presented values increase irregularly with the increasing temperature from 0.001 to 0.018 S cm-1 as expected in a semiconductor material. The thermal conductivity is lower than 0.44 - 775 W m-1 K-1 which is quite anomalous in comparison with the thermal conductivity of other oxides.

Tribological Performance Optimization of Electroless Nickel Coatings Under Lubricated Condition

2018 ◽  
pp. 250-280 ◽  
Author(s):  
Santanu Duari ◽  
Arkadeb Mukhopadhyay ◽  
Tapan Kumar Barman ◽  
Prasanta Sahoo
Keyword(s):  
Performance Optimization ◽  
Friction And Wear ◽  
Electroless Nickel ◽  
Heat Treating ◽  
Wear Depth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Electroless Ni ◽  
Scanning Electron

The present chapter aims to determine optimal tribo-testing condition for minimum coefficient of friction and wear depth of electroless Ni-P, Ni-P-W and Ni-P-Cu coatings under lubrication using grey relational analysis. Electroless Ni-P, Ni-P-W and Ni-P-Cu coatings are deposited on AISI 1040 steel substrates. They are heat treated at suitable temperatures to improve their hardness. Coating characterization is done using scanning electron microscope, energy dispersive X-Ray analysis and X-Ray diffraction techniques. Typical nodulated surface morphology is observed in the scanning electron micrographs of all the three coatings. Phase transformation on heat treating the deposits is captured through the use of X-Ray diffraction technique. Vicker's microhardness of the coatings in their as-deposited and heat treated condition is determined. Ni-P-W coatings are seen to exhibit the highest microhardness. Friction and wear tests under lubricated condition are carried out following Taguchi's experimental design principle. Finally, the predominating wear mechanism of the coatings is discussed.

Research on the Insulation Materials with Sugar Filter Mud as Pore-Forming Agent and Jilin Clay as Aggregate

2013 ◽  
Vol 361-363 ◽  
pp. 682-685
Author(s):  
Chao Qian ◽  
Wen Yuan Gao ◽  
Chun Yuan Luo ◽  
Li Dong Tuo ◽  
Hai Yuan Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electron Microscope ◽  
Flexural Strength ◽  
Scanning Electron Microscope ◽  
Elemental Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Insulation Materials ◽  
Filter Mud ◽  
Scanning Electron

Insulation materials with flexural strength 5.238 MPa and porosity 39.24% obtained at 1050 °C for 0.5 h show that its bulk density of the materials decreased down to 1.252 g/cm3using clay as aggregate. Due to change the amount of sugar filter mud, the porosity arises from 37.07% to 39.24% and the thermal conductivity decreases from 0.086 to 0.052 W·m-1·K-1. The clay and wastes were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and chemical elemental analysis. The main crystalline phases of sample observed by XRD are quartz, mullite and anorthite. The insulation materials were manufactured from clay and the optimal proportion of wastes.

scholarly journals Degradation of Methylene Blue Dye in the Presence of Visible Light Using SiO2@α-Fe2O3 Nanocomposites Deposited on SnS2 Flowers

2018 ◽  
Author(s):  
Sridharan Balu ◽  
Kasimayan Uma ◽  
Guan-Ting Pan ◽  
Thomas C.-K. Yang ◽  
Sayee Kannan Ramaraj
Keyword(s):  
Methylene Blue ◽  
Three Dimensional ◽  
Semiconductor Materials ◽  
Blue Dye ◽  
Core Shell ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Scanning Electron

Semiconductor materials have been shown to have better photocatalytic behavior and can be utilized for the photodegradation of organic pollutants. In this work, three-dimensional flower-like SnS2 were synthesized by a facile hydrothermal method. Core-shell structured SiO2@α-Fe2O3 nanocomposites were then deposited on the top of the SnS2 flowers. The as-synthesized nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), Brunauer-Emmett-Teller (BET) and photoluminescence spectroscopy (PL). The photocatalytic behavior of the SnS2-SiO2@α-Fe2O3 nanocomposites was observed by observing the degradation of methylene blue (MB). The results show an effective enhancement of photocatalytic activity for the degradation of MB especially for the 15 wt. % SiO2@α-Fe2O3 nanocomposites on SnS2 flowers.

Effect of Preparation on Standard Dry Density and Strength of Foamed Cement by Orthogonal Test

2014 ◽  
Vol 577 ◽  
pp. 1119-1122
Author(s):  
Na Li ◽  
Qi Wang ◽  
Peng Song
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
High Strength ◽  
Xrd Analysis ◽  
Orthogonal Test ◽  
Dry Density ◽  
Light Weight ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

In this paper, we studied the effect of preparation on standard dry density and strength of foamed cement by orthogonal test. The results indicate that the more excellent combination is A1B1C1, namely G1, the standard dry density is 376 kg/m3, the flexural and compressive strengths are 0.43 MPa and 0.8 MPa respectively, and the thermal conductivity is 0.074 W/(m·K), which conforms to the characteristics of light weight and high strength. Fewer Ca (OH)2 crystals and more C-S-H gel generated in G1 through scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis is the reason for its high strength.

Preparation and Research of High-Temperature Foam Ceramic

2013 ◽  
Vol 357-360 ◽  
pp. 1353-1357
Author(s):  
Xiao Li Ji ◽  
Zhuo Chen
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
High Temperature ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Micro Structure ◽  
Foaming Agent ◽  
X Ray ◽  
Foam Ceramic ◽  
Scanning Electron

High-temperature foam ceramics were produced from sludge, Zhongxiang porcelain sand, shale and sand, with addition of SiC 0.15%~0.40% as foaming agent, respectively, sintered at 1130°C~1160°C. The phase composition and micro structure of sintered samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and density, compressive strength and thermal conductivity were evaluated. The results showed that the main phase of amorphous phase plagioclase in sintered samples and interior of samples with a large number of uniformly distributed closed pores, rose sintering temperature and increased SiC addition leading to pores size enlarged and density, compressive strength and thermal conductivity diminished.

scholarly journals Synthesis, crystal structure, and thermal properties of poly[aqua(μ5-2,5-dicarboxybenzene-1,4-dicarboxylato)strontium]

2020 ◽  
Vol 76 (3) ◽  
pp. 354-359
Author(s):  
Samia Mokhtari ◽  
Chahrazed Trifa ◽  
Sofiane Bouacida ◽  
Chaouki Boudaren ◽  
Mohammed S.M. Abdelbaky ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Thermal Analysis ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Tetracarboxylic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylate Groups ◽  
Scanning Electron

A coordination polymer formulated as [Sr(H2BTEC)(H2O)] n (H4BTEC = benzene-1,2,4,5-tetracarboxylic acid, C10H6O8), was synthesized hydrothermally and characterized by single-crystal and powder X-ray diffraction, scanning electron microscopy and thermal analysis. Its crystal structure is made up of a zigzag inorganic chain formed by edge-sharing of [SrO8] polyhedra running along [001]. Adjacent chains are connected to each other via the carboxylate groups of the ligand, resulting in a double-layered network extending parallel to (100). O—H...O hydrogen bonds of medium-to-weak strength between the layers consolidate the three-dimensional structure. One of the carboxylic OH functions was found to be disordered over two sets of sites with half-occupancy.

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 Facile preparation of a novel catalytic particle electrode from sewage sludge and its electrocatalytic performance in three-dimensional heterogeneous electro-Fenton

2017 ◽  
Vol 76 (9) ◽  
pp. 2350-2356 ◽  
Author(s):  
Baolin Hou ◽  
Renjian Deng ◽  
Bozhi Ren ◽  
Zhi Li
Keyword(s):  
Sewage Sludge ◽  
Three Dimensional ◽  
Fe3o4 Magnetic Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Particle ◽  
Toc Removal ◽  
Facile Preparation ◽  
The Stability ◽  
Scanning Electron

Abstract A novel type of catalytic particle electrode (SAC-Fe) was developed from sewage sludge and iron sludge via a facile method. The catalytic particle electrodes (CPEs) were also supposed to be heterogeneous catalyst for electro-Fenton (EF). The CPEs were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). SAC-Fe showed superior porous structure and higher adsorption capacity and catalytic activity than Fe3O4 magnetic nanoparticles. Catechol and total organic carbon (TOC) removal efficiency can reach 96.7% and 88.3% after three-dimensional (3D) EF with SAC-Fe as CPEs. A possible mechanism was deduced based on adsorption tests and radicals detection. Meanwhile, the stability and reusability of the CPEs were evaluated.

Hydrothermal Synthesis of α-MnO2 Nanostructures at Low Temperature and their Electrochemistry Properties

2014 ◽  
Vol 556-562 ◽  
pp. 166-168
Author(s):  
Si Liang Li ◽  
Ya Jie Guo ◽  
Jing Juan Pu
Keyword(s):  
Electron Microscopy ◽  
Electronic Conductivity ◽  
Three Dimensional ◽  
Cyclic Voltammograms ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
X Ray ◽  
Capacitive Behavior ◽  
Facile Hydrothermal Route ◽  
Scanning Electron

A novel three-dimensional MnO2 have been successfully prepared by a facile hydrothermal route without any catalysts below 90oC. They were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In addition, the obtained α-MnO2 nanorods showed excellent capacitive behavior, cyclic voltammograms stability and favorable electronic conductivity.

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