scholarly journals Influence of corn flour as pore forming agent on porous ceramic material based mullite: Morphology and mechanical properties

2016 ◽  
Vol 48 (1) ◽  
pp. 29-39 ◽  
Author(s):  
J.G. Ayala-Landeros ◽  
V. Saucedo-Rivalcoba ◽  
S. Bribiesca-Vasquez ◽  
V.M. Castaño ◽  
A.L. Martínez-Hernández ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ceramic Material ◽  
Volume Fraction ◽  
Porous Ceramic ◽  
Corn Flour ◽  
Crystalline Phases ◽  
Talcum Powder ◽  
X Ray ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

Porous material was processed by the mixing, molding and pressing the ceramic material, afterward burnout and sintering; through the forming porous, using corn flour at different concentration (10, 15 and 20 wt.%) as a pore forming agent; in order to determinate the influence of porous on the mechanical, morphological and structural properties. The effect of the volume fraction of corn flour in the mullite matrix, at various sintering temperature from 1100, 1200, 1300 and 1500?C were tested by Diffraction X ray, showing changes in crystalline phases of mullite (3Al2O3-2SiO2), as result of sintered temperatures. Presence of talcum powder in formula, also cause the formation of the cordierite and cristobalite crystalline phases, giving stability and adhesion to the structure of ceramic material. When sintering at temperatures between 1300 to 1500?C, and it was used the concentration of corn flour 15-20 wt.% as forming agent porous, it was found the better mechanical properties. The scanning electron microscopy analysis shows the presence of open porosity and anisotropy.

Microstructure and Mechanical Properties of Cr-W-B-N Coating Deposited by DC Reactive Magnetron Co-Sputtering

2013 ◽  
Vol 651 ◽  
pp. 430-435
Author(s):  
Lin Yung Tseng ◽  
Jhewn Kuang Chen ◽  
Kai Hung Hsu ◽  
Wan Yu Wu ◽  
Chi Lung Chang
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Nitrogen Plasma ◽  
Reactive Magnetron ◽  
Tungsten Content ◽  
Micro Hardness ◽  
Depth Sensing ◽  
Crystalline Phases ◽  
Sputtering Deposition ◽  
X Ray

Nanocomposite Cr-W-B-N coatings with various tungsten contents were synthesized on silicon wafer substrates. The used technique is a DC reactive magnetron co-sputtering deposition equipped with a Cr-B alloy target with 20 at.% B and a W target in a mixed argon/nitrogen plasma atmosphere. Composition and microstructure of the obtained coatings were investigated using X-ray diffraction, X-ray Photoelectron Spectroscope and transmission electron microscope while the micro-hardness was measured using a depth-sensing nano-indenter. The results have shown that the microstructure and the mechanical properties of Cr-W-B-N coatings were strongly dependent on either the tungsten content or the volume fraction of W-N crystalline phases. It was observed that the micro-hardness of Cr-W-B-N coatings is lower than that of Cr-B-N coating as the tungsten content is less than 24 at.% and the volume fraction of W-N crystalline phases is lower than 37 vol.%. As the tungsten content further increased to 30 at.% and the volume fraction of W-N crystalline phases increased to 55 vol.%, the micro-hardness of Cr-W-B-N coating was found enhanced to 19 GPa and higher than Cr-B-N film. It was also obtained that the volume fraction of Cr-N crystalline phases is inversely proportional to the volume fraction of W-N crystalline phases.

scholarly journals Physico-Mechanical Properties of Particleboards Produced from Macadamia Nutshell and Gum Arabic

2021 ◽  
Vol 11 (23) ◽  
pp. 11138
Author(s):  
Derrick Mirindi ◽  
Richard O. Onchiri ◽  
Joseph Thuo
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Gum Arabic ◽  
Physical And Mechanical Properties ◽  
General Purpose ◽  
Modulus Of Rupture ◽  
Thickness Swelling ◽  
X Ray ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

Due to the rising prices and high demand for panels and the fact that formaldehyde—a known carcinogen—is used to manufacture conventional particleboard, this study investigated the suitability of particleboard formed from ground macadamia nutshells mixed with 50%, 40%, 30%, and 20% of gum Arabic and determined its physical and mechanical properties. The specific gravity, the bulk density, the x-ray fluorescence, and the scanning electron microscopy analysis of the two materials were analyzed. After production, the particleboards were cured for 56 days in an acclimatized room; then, the physical and mechanical properties were evaluated. Particleboards mixed with 50% gum Arabic and 50% macadamia nutshell showed good results in terms of the lowest average values of water absorption (9.42%) and thickness swelling (6.22%) after 24 h of immersion in distilled water as well as the highest density (1219.20 kg/m3), modulus of rupture (12.21 MPa), modulus of elasticity (1.81 GPa), internal bond strength (1.25 MPa), and compressive strength (22.54 MPa). According to ANSI/A208.1-1999, the particleboards produced met the standard for general-purpose boards except for water absorption (WA) and thickness swelling (TS) characteristics, which were above the maximum of 8% and 3%, respectively.

Infiltrated Spinel-Based Ceramic (MgAl2O4) for Dental Application

2016 ◽  
Vol 881 ◽  
pp. 176-180
Author(s):  
Roberto de Oliveira Magnago ◽  
Fernanda de Assis Baião Miranda Pereira ◽  
Paula Cipriano da Silva ◽  
José Vitor Candido de Souza ◽  
Claudinei dos Santos
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Ceramic Material ◽  
Porous Ceramic ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Toughness ◽  
Dental Application ◽  
Ceramic Blocks ◽  
Scanning Electron

This work developed a ceramic material for dental application, spinel-base (MgAl2O4), a ceramic material with recognized translucency. Spinel powders were uniaxially pressed at 100 MPa and pre-sintered in order to obtain porous ceramic blocks. The pre-sintered blocks were characterized and indicated 80% of relative density. X-ray diffraction (XRD) only showed MgAl2O4 phase. Samples with 15 x 15 x 1 mm were submitted to infiltration using glass rich in lanthanum (La). The products were characterized by scanning electron microscopy (SEM) and mechanical properties, as hardness and fracture toughness. Results were compared to the commercial product VITA-InCeram Spinell. Relative densities exceeding 92%, hardness around 900 HV and high toughness 2.5 MPa.m1/2 were obtained for both examined systems.

Macroprobe Mode for the Study of Segregation in Steels

1990 ◽  
Vol 48 (2) ◽  
pp. 260-261
Author(s):  
Auclair Gilles ◽  
Benoit Danièle
Keyword(s):  
Mechanical Properties ◽  
Spatial Distribution ◽  
High Performance ◽  
Volume Fraction ◽  
Sheet Steel ◽  
Acquisition Time ◽  
Chemical Information ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Optical Micrographs

During these last 10 years, high performance correction procedures have been developed for classical EPMA, and it is nowadays possible to obtain accurate quantitative analysis even for soft X-ray radiations. It is also possible to perform EPMA by adapting this accurate quantitative procedures to unusual applications such as the measurement of the segregation on wide areas in as-cast and sheet steel products.The main objection for analysis of segregation in steel by means of a line-scan mode is that it requires a very heavy sampling plan to make sure that the most significant points are analyzed. Moreover only local chemical information is obtained whereas mechanical properties are also dependant on the volume fraction and the spatial distribution of highly segregated zones. For these reasons we have chosen to systematically acquire X-ray calibrated mappings which give pictures similar to optical micrographs. Although mapping requires lengthy acquisition time there is a corresponding increase in the information given by image anlysis.

Effect of Si Content on Microstructure and Properties of 60Si2CrVA Spring Steel

2014 ◽  
Vol 968 ◽  
pp. 63-66 ◽  
Author(s):  
Fei Zhao ◽  
Zhan Ling Zhang ◽  
Jun Shuai Li ◽  
Cui Ye ◽  
Ni Li
Keyword(s):  
Mechanical Properties ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Testing Machine ◽  
Spring Steel ◽  
Impact Testing ◽  
X Ray ◽  
Comprehensive Properties ◽  
Spring Steels ◽  
Si Content

The microstructure and mechanical properties of the four spring steels with different Si content treated by Q-I-Q-T process were studied by metallographic microscope, MTS, impact testing machine and X-ray stress analyzer. The results show that the tensile strength and yield strength is first increased and then decreased with the increase of Si content, the volume fraction of retained austenite and elongation are fist decreased and then increased when the Si content is less than 2.1%, and the microstructure become finer and homogeneous. When Si content reaches 2.1%, the comprehensive properties of 60Si2CrVA spring steel is the best.

Stress in Hydrogenated Microcrystalline Silicon Thin Films

1999 ◽  
Vol 557 ◽  
Author(s):  
D. Peiró ◽  
C. Voz ◽  
J. Bertomeu ◽  
J. Andreu ◽  
E. Martínez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Vapor Deposition ◽  
Volume Fraction ◽  
Chemical Vapor ◽  
Hot Wire ◽  
X Ray Diffraction ◽  
Microcrystalline Silicon ◽  
X Ray ◽  
Silicon Thin Films ◽  
Abrupt Changes

AbstractHydrogenated microcrystalline silicon films have been obtained by hot-wire chemical vapor deposition (HWCVD) in a silane and hydrogen mixture at low pressure (<5 × 10-2 mbar). The structure of the samples and the residual stress were characterised by X- ray diffraction (XRD). Raman spectroscopy was used to estimate the volume fraction of the crystalline phase, which is in the range of 86 % to 98%. The stress values range between 150 and -140 MPa. The mechanical properties were studied by nanoindentation. Unlike monocrystalline wafers, there is no evidence of abrupt changes in the force-penetration plot, which have been attributed to a pressure-induced phase transition. The hardness was 12.5 GPa for the best samples, which is close to that obtained for silicon wafers.

Trace Element Detection In Particle X-Ray Spectrum

1997 ◽  
Vol 3 (S2) ◽  
pp. 901-902
Author(s):  
John A. Small
Keyword(s):  
X Ray ◽  
Minor Elements ◽  
Elemental Concentrations ◽  
Eds Analysis ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Counting Statistics ◽  
Automated Scanning ◽  
Individual Particles ◽  
Concentration Levels

One of the main goals of automated scanning electron microscopy analysis (ASEM) of particles is to provide macroscopic phase and compositional information on particle populations based on the energy dispersive x-ray spectrometry, EDS, analysis of several hundred to several thousand individual particles from the sample. The selection and identification of the various elemental groupings is often accomplished by applying techniques for grouping data, such as multivariate or cluster analysis methods, to characteristic x-ray intensities or normalized elemental concentrations. Particle groupings are often based on major and minor elements with concentrations greater than about 1-2 wt. percent. At these concentration levels, the peak-to-background ratios for the characteristic x-ray peaks are sufficiently large that in the absence of severe peak overlaps the elements can be easily identified even in spectra with poor counting statistics. Additional refinement in particle groupings may be possible if reliable information can be obtained on the trace elements present in particles at less than about 1-2 wt.%.

Fabrication and mechanical properties of Al/Al2O3 composite bodies by reactive infiltration of molten Al into SiO2 preform

2000 ◽  
Vol 15 (11) ◽  
pp. 2314-2321 ◽  
Author(s):  
Noboru Yoshikawa ◽  
Singo Funahashi ◽  
Shoji Taniguchi ◽  
Atsushi Kikuchi
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Sintering Temperature ◽  
Pore Space ◽  
Pressure Infiltration ◽  
X Ray ◽  
Reactive Infiltration ◽  
Pore Size Distributions ◽  
Different Temperatures ◽  
Si Content

Al/Al2O3 composites were fabricated by a displacement reaction between SiO2 and molten Al. In this study, fabrication of Al/Al2O3 composites was attempted by means of reactive infiltration to provide variation of their mechanical properties. SiO2 preforms having various porosities and pore size distributions were prepared by sintering the powder at different temperatures between 1273 and 1723 K. Molten Al was infiltrated at 1373 K without application of pressure. Infiltration kinetics were studied and the microstructures of the composite bodies were observed by means of scanning electron microscopy (with energy dispersive x-ray microanalysis), wave dispersive x-ray microanalysis, and x-ray diffractions. The infiltrated specimens were mainly composed of Al and α–Al2O3 phases, and the Si content was less than 5 at.%. Volume fraction of Al phase in the composite bodies was not altered very much with the porosities of the SiO2 preforms because of the difficulty in filling out the entire pore space. Properties and microstructures of Al/Al2O3 composites, however, were dependent on the sintering temperature of the SiO2 preforms. In the case of low sintering temperature, a thick Al channel existed, which deformed upon compression. In the case of high sintering temperature, the microstructure became homogeneous and had thinner Al channels. The composite bodies became brittle. The deformation behavior was shown to be changed from ductile to brittle as an increase of the sintering temperature of the preforms.

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