Magnesite Effect to the Alumina Sintering for Heat Sink Application

2013 ◽  
Vol 465-466 ◽  
pp. 70-75
Author(s):  
Nor Hafiez Mohamad Nor ◽  
Muhammad Hussain Ismail ◽  
Nur Atikah Abu Kasim ◽  
Wan Dung Teng ◽  
M.I.I. Idris
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Heat Sink ◽  
Density Measurement ◽  
Xrd Analysis ◽  
Modern World ◽  
X Ray Diffraction ◽  
Electronic Components ◽  
X Ray ◽  
Sintered Temperature

In the modern world with an extensive improvement of science and technologies, alumina (Al2O3) ceramics have been identified as one of the usable materials in production of electronic components. This project attempts to investigate the magnesite (MgCO3) effect to Al2O3 sintering for heat sink application. The effect of MgO percentage varying from 0% to 50% has been in investigated, emphasizing on the flexural strength test, thermal conductivity test, elastic modulus test, shrinkage percentage and density measurement. The result revealed that the MgO give an effect to the final thermal conductivity and mechanical properties of Al2O3 material at high sintering temperature (i.e. at temperature of 1600°C). Throughout an X-ray diffraction (XRD) analysis of Al2O3 and MgO compositions, it was revealed that spinel, periclase and corundum phases exist for all sintered temperature which contributes to strengthen grain boundaries and improved mechanical properties.

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 Effects of Bi2O3 Doping on the Mechanical Properties of PbO Ceramic Pellets Used in Lead-Cooled Fast Reactors

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1948 ◽  
Author(s):  
Yan Ma ◽  
Anxia Yang ◽  
Huiping Zhu ◽  
Arslan Muhammad ◽  
Pengwei Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Eutectic Alloy ◽  
Composite Ceramic ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Oxygen Control ◽  
Fast Reactors ◽  
Future Studies ◽  
X Ray ◽  
Lead Bismuth Eutectic

In this paper, the effects of Bi2O3 doping on the mechanical properties of PbO ceramic pellets were studied. Different ratios of Bi2O3/PbO (i.e., xBi2O3-(1−x) PbO, where x is 0, 1, 3, 5, or 7 wt.%) were fabricated and sintered at 570, 620, and 670 °C. Mechanical properties including density, hardness, flexural strength, and sintering of PbO were studied for each of the aforementioned compositions. Phase composition, microstructure, and the worn surfaces of the composites were characterized by scanning electron microscopy and X-ray diffraction (XRD). The XRD analysis revealed that a solid solution formed in the composite ceramic. The best suited conditions of temperature and doping of Bi2O3 for optimal sintering were found to be 620 °C and 3 wt.%, respectively. The hardness of the 3 wt.% Bi2O3-97 wt.% PbO ceramic was found to be 717 MPa, which is about four times higher than the hardness of pure PbO. In addition, the strength of the composites was found to be 43 MPa, which is two times higher than that of pure PbO. The integrity of the composites was verified using the lead–bismuth eutectic alloy flushing experiment. The results of this research paper are important for future studies of oxygen control in the lead–bismuth eutectic alloy of lead-cooled fast reactors.

MECHANICAL PROPERTIES OF A POLYURETHANE/MONTMORILLONITE NANOCOMPOSITE FEATURING ORGANOMODIFICATION SYNTHESIZED VIA IN SITU POLYMERIZATION

2015 ◽  
Vol 88 (1) ◽  
pp. 138-146 ◽  
Author(s):  
Rouhollah Bagheri ◽  
Reza Darvishi
Keyword(s):  
Mechanical Properties ◽  
In Situ Polymerization ◽  
Xrd Analysis ◽  
Silicate Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
End Groups ◽  
Layer Sample ◽  
Silicate Layers

ABSTRACT In this study, polyurethane (PU)/organomodified montmorillonite (cloisite®30B) is synthesized via in situ polymerization by reaction of an ether-based prepolymer with the isocyanate end groups and adiamine chain extender (4, 4-methylene-bis(2-chloroaniline)) in the presence of different amounts of nanoparticles dispersed in the prepolymer matrix by an ultrasonic mixer for 1 h. The synthesized polymers are cast on a pretreated carbon steel sheet and cured at 120 °C in an oven. The PU and its composites have been characterized by using Fourier transform infrared spectroscopy, X-ray diffraction (XRD), and mechanical testing. The XRD analysis of the cured samples containing 1 to 3 wt% cloisite30B showed intercalation segments in the silicate layers and exfoliation for 0.5 wt% nanoparticles. The highest mechanical properties were obtained using the cured exfoliated silicate layer sample. A twofold increase in the ultimate tensile strength and a 2.3 times increase in the adhesion strength were found for 0.5 wt% organoclay/PU as compared with that of pure PU. In addition, the exfoliated structure sample exhibited a 16% reduction in abrasion compared with that of pure PU.

Identification and enhancement of the thermal and mechanical properties of two types of plasters successively derived from gypsum: from the Safi basin and the High Atlas of Marrakech, Morocco

2020 ◽  
Author(s):  
imane baba ◽  
Mounsif Ibnoussina ◽  
Omar Witam
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Mechanical Strength ◽  
Setting Time ◽  
Density Measurement ◽  
Raw Material ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
X Ray Diffraction ◽  
High Atlas

<p>Over the past few decades, the construction industry has focused on sustainable, environmentally friendly and easily recyclable materials. The objective of this work is to characterize and enhance the thermal conductivity, mechanical strength and setting time of a composite material based on plaster and lime. This material is designed for use in plasters.</p><p>Two types of gypsum are studied, the first one belongs to the Safi basin, the second one characterizes the High Atlas of Marrakech and precisely Douar Tafza. Geologically speaking, the two sites have many similarities. They are characterized by a Meso-Cenozoic age coverage covering a deformed Paleozoic age basement.</p><p>The characterization of the plaster's raw material, gypsum, was necessary to determine its physical and geotechnical properties, mineralogy, thermal behaviour and microscopic structure. Several analyses have been developed such as: pycnometer density measurement, X-ray diffraction, infrared spectroscopy and scanning electron microscopy.</p><p>We made samples, of standardized dimensions, of two mixtures based on the two types of plaster reinforced by the addition of two types of lime from different localities. The latter are from Marrakech and the Agadir region. The water/plaster mass ratio was set at 0.75 and the addition of lime was achieved by increasing its percentage in slices by 12.5% and up to 50%.</p><p>The reinforcement of plaster with lime has enhanced its thermal and mechanical properties and setting time. The measurements show that the addition of lime has reduced the thermal conductivity and increased the mechanical strength of both types of plaster. In addition, following the addition of lime, the setting time has decreased and the basicity of the material has increased. Noting that the intrinsic properties of the raw material influence the mechanical and thermal properties of the material.</p><p><strong>Keywords:</strong>   plaster, enhancement, properties, mechanical, thermal, Morocco</p>

Measurement of Alloying Degree of Galvannealed Steels by X-Ray Diffraction

2006 ◽  
Vol 321-323 ◽  
pp. 1461-1464 ◽  
Author(s):  
Hyoung Kuk Park ◽  
Jea Hwa Hong ◽  
Chong Soo Lee
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Quantitative Analysis ◽  
Xrd Analysis ◽  
Pls Regression ◽  
Processing Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Excellent Corrosion Resistance ◽  
Galvannealed Steel

Galvannealed steels are produced by reheating of Zinc-coated steels, in which the iron and the zinc are interdiffused to form Zn-Fe intermatallic compound. In recent years, application of galvannealed steel has increased due to its excellent corrosion resistance, good weldability and paintability. Galvannealed production requires strict control of processing conditions to obtain an optimal alloying degree in the coatings. The analysis of the alloying degree is very important since they are closely related to the corrosion and mechanical properties. This study is measurement of alloying degree of the galvannealed steel by using the XRD. Partial least squares (PLS) model is a powerful multivariate tool that has been successfully applied to the quantitative analysis of data in XRD. The alloying degree was determined by using PLS regression to a concentration accuracy of 0.2%. The XRD analysis and proposed PLS model can be successfully used to determine the alloying degree of industrially produced galvannealed steel.

Effect of expandable and expanded graphites on the thermo-mechanical properties of polyamide 11

2018 ◽  
Vol 51 (2) ◽  
pp. 175-190 ◽  
Author(s):  
F Oulmou ◽  
A Benhamida ◽  
A Dorigato ◽  
A Sola ◽  
M Messori ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Xrd Analysis ◽  
Crystal Form ◽  
X Ray Diffraction ◽  
Polyamide 11 ◽  
X Ray ◽  
Diffraction Peaks ◽  
Graphite Composites ◽  
And Storage

The preparation and thermo-mechanical characterization of composites based on polyamide 11 (PA11) filled with various amounts of both expandable and expanded graphites are presented. Investigation conducted using X-ray diffraction (XRD), scanning electron microscopy and surface area analyses indicated how graphite expanded under the selected processing conditions. The XRD analysis on PA11/graphite composites revealed no change in the crystal form of the PA11, while the presence of diffraction peaks associated to the graphite-stacked lamellae can be still detected. All the investigated composites showed an improvement of the thermal stability and mechanical properties (elastic and storage moduli).

Mechanical Properties of Fly Ash-Slag-Dredged Silt System Stimulated by Alkali

2013 ◽  
Vol 807-809 ◽  
pp. 1140-1146 ◽  
Author(s):  
Yi Xuan Chen ◽  
Xiu Li Sun ◽  
Zhi Hua Li
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Fly Ash ◽  
Construction Materials ◽  
Xrd Analysis ◽  
Test Results ◽  
X Ray Diffraction ◽  
Shear Tests ◽  
X Ray ◽  
Direct Shear Tests

The objective of this work is to investigate the stimulation effect of the addition of alkali on the fly ash and slag for stabilizing dredged silt. Based on the test results, a viable alternative for the final disposal of dredged silt as subgrade construction materials were proposed. For this purpose, several mixtures of dredged silt-fly ash-slag and alkali were prepared and stabilized/solidified. In this system, fly ash and slag were used as hardening agents (solidified materials) of dredged silt and alkali was used as activator of fly ash and slag. The shear strength of the mixture was tested by several direct shear tests. Furthermore, X-Ray Diffraction (XRD) analysis was used to determine the hydration products of the system. The specimens were tested in order to determine the shear strength changes versus hydration time and the alkali content. It is indicated that mechanical properties of solidified silt are improved significantly by addition of fly ash and slag stimulated by alkali.

Characterization of Ti-xNb (x = 25 – 35) Alloys in as Melt and Annealed States

2019 ◽  
Vol 946 ◽  
pp. 287-292
Author(s):  
Alexander Thoemmes ◽  
Ivan V. Ivanov ◽  
Alexey Ruktuev
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Α Phase ◽  
Nb Content ◽  
Scanning Electron

The effect of Nb content on microstructure, mechanical properties and phase formation in as-melt and annealed binary Ti-Nb alloys were investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) analysis. The content of Nb varied in the range 25-35 mass % leading to significant changes in the microstructure. The annealed and furnace-cooled binary Ti-Nb samples exhibited HCP martensitic α` phase at a Nb content below 27.5 mass % and metastable BCC β phase at higher contents of Nb. The mechanical properties of alloys depended strongly on the Nb content and type of the dominating phase.

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.

Synthesis and Characterization of TiO2Nanoparticles with Polycarbonate and Investigation of its Mechanical Properties

2017 ◽  
Vol 16 (05n06) ◽  
pp. 1750012 ◽  
Author(s):  
Farhad Jahantigh ◽  
Mehdi Nazirzadeh
Keyword(s):  
Mechanical Properties ◽  
Weight Fraction ◽  
Xrd Analysis ◽  
Tensile Tests ◽  
Nanocomposite Films ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Stability Of

In this project, nanocomposite films were prepared with different Titanium dioxide (TiO2) percentages. Properties of polycarbonate (PC) and PC–TiO2nanocomposite films were studied by X-ray diffraction (XRD) analysis and Fourier transform infrared (FTIR) spectroscopy. The structure of samples was studied by XRD. The mechanical properties of PC–TiO2nanocomposite films were investigated by conducting tensile tests and hardness measurements. Thermal stability of the nanocomposites was studied by thermogravimetric analysis (TGA) method. The elastic modulus of the composite increased with increasing weight fraction of nanoparticles. The microhardness value increases with increasing TiO2nanoparticles. The results of tensile testing were in agreement with those of micro-hardness measurements. In addition, TGA curves showed that nanocomposite films have higher resistance to thermal degradation compared to polycarbonate. There are many reports related to the modification of polycarbonate films, but still a systematic study of them is required.

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