scholarly journals Manufacture of ceramics with high mechanical properties from red mud and granite waste

2019 ◽  
Vol 69 (333) ◽  
pp. 180 ◽  
Author(s):  
I. Gonzalez-Triviño ◽  
J. Pascual-Cosp ◽  
B. Moreno ◽  
M. Benítez-Guerrero
Keyword(s):  
Mechanical Properties ◽  
Red Mud ◽  
Bauxite Residue ◽  
Hardness Test ◽  
X Ray Diffraction ◽  
Alumina Production ◽  
X Ray ◽  
Test Electron ◽  
Electron Scanning Microscopy ◽  
Global Inventory

Red mud (bauxite residue) is an alkaline suspension that is the by-product of alumina production via the Bayer process. Its elevated annual production and the global inventory of red mud determine its valorisation. Granite can be used as a source of fluxing oxides for the ceramic industry, as can the flake-shaped waste generated during the flaming of granite. In this work, a set of ceramic pieces made of red mud and granite waste are prepared and characterised via X-ray diffraction, a hardness test, electron scanning microscopy, a leaching test, and determining open porosity, water absorption, bulk density and flexural strength of the samples. The main crystalline phases in the high-temperature fired products are hematite, pseudobrookite and anorthite; the presence of magnetite reveals their ferrimagnetic character. All samples present high mechanical properties. Leaching results are below critical levels established by regulations.

scholarly journals Effect of gas composition and temperature on reduction characteristic in red mud-coal composite pellets

2019 ◽  
Vol 23 (5 Part A) ◽  
pp. 2561-2568
Author(s):  
Yi Man ◽  
Jun-Xiao Feng ◽  
Zhan-Min Yang ◽  
Zeng-Lu Song ◽  
Chao Yang
Keyword(s):  
Red Mud ◽  
Reduction Process ◽  
Gas Composition ◽  
X Ray Diffraction ◽  
Alumina Production ◽  
X Ray ◽  
N2 Atmosphere ◽  
Composite Pellets ◽  
Optimum Reaction ◽  
Bayer Red Mud

The disposal of red mud, which is the by-product obtained from alumina production, has brought about environmental pollution because of its caustic nature as well its metal and alkaline contents. Red mud-coal composite pellets were directly reduced to deal with red mud. The influences of reduction temperature and gas composition on the reaction were studied. Experiment results indicated that the optimum reaction parameters were a temperature of 1100?C and an H2 atmosphere. Reduction degrees in H2 and CO atmospheres were significantly higher than those in N2 atmosphere. Reduction did not strictly follow the Fe2O3 ? Fe3O4 ? FeO ? Fe sequence in N2 atmosphere, and this phenomenondid not occur in H2 atmosphere. This gas?solid combination reduction process is appropriate for recovering Fe from Bayer red mud. Meanwhile, the microstructure and phase transformation of the reduction process were investigated via scanning electron microscopy and X-ray diffraction.

scholarly journals Effects of TiO2/SiO2 Reinforced Nanoparticles on the Mechanical Properties of Green Hybrid Coating

2015 ◽  
Vol 47 ◽  
pp. 56-66 ◽  
Author(s):  
Mohammed Gobara
Keyword(s):  
Mechanical Properties ◽  
Sol Gel ◽  
Hardness Test ◽  
Silica Sol ◽  
X Ray Diffraction ◽  
Properties Of Coatings ◽  
X Ray ◽  
Hybrid Silica ◽  
Transmission Electron ◽  
Adhesion Performance

Titanium and silica oxides nanoparticles were introduced into hybrid silica sol–gel/epoxy coating to enhance the mechanical properties of coatings. Titanium dioxide (TiO2) and silica oxide (SiO2) were chemically synthesised before adding to the prepared silica sol gel coating. X-ray diffraction (XRD), Energy-dispersive x-ray analysis (EDX) and Transmission Electron microscope (TEM) were used to characterize the prepared nanoparticles. The coating was then applied to 3003 aluminium alloy (AA3003) surface. The adhesion performance of different sol gel coating compositions was investigated using shear test to define the influence of nanoparticles on adhesive strength of the coating. The Rockwell C hardness test was used to study the micro-hardness of different compositions of sol gel coating. Also, contact angel was used to investigate the hydrophobicity of the coatings. The results showed that there was a significant improvement of the adhesion performance of hybrid silica sol gel coating due to addition of TiO2 and the hydrophobicity of sol gel coating was increased due to addition of SiO2 nanoparticles.

scholarly journals The Effect of Solution Treatment on Mechanical Properties and Micro Structure of Zr-10Ti-Sn Alloy for Screw Dental Implant Application

2021 ◽  
Vol 2 (2) ◽  
pp. 91
Author(s):  
Deva Ayu Utami ◽  
R. Henny Mulyani ◽  
Djoko Hadi Prajitno
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Dental Implant ◽  
Solution Treatment ◽  
Hardness Test ◽  
Alpha Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Corrosion Resistance ◽  
Low Modulus

<p>The research was to investigate the effect of solution treatment on the mechanical properties and microstructure of Zr-10Ti-Sn alloy for dental implant biomaterials. The addition of titanium as a material has good corrosion resistance and stannum as a material has a low modulus young and can increase hardness of the alloy in accordance with the material criteria as a dental implant, which must have good corrosion resistance and good mechanical properties. Zr -10Ti-xSn alloy (x = 0, 2, and 4% wt) were subjected to solution treatment with temperature variations of 900<sup>o</sup>C, 1000<sup>o</sup>C and 1100<sup>o</sup>C with water quenching. The results  is increase in stannum content can also increase the hardness because stannum can inhibit the enlargement of grain boundaries and the microstructure is more homogeneous and tends to be smaller with an uniaxial shape. Stannum as alpha stabilizer will form a hard alpha phase. Micro Vickers hardness test with the highest hardness value of 601,438 HV alloy Zr-10Ti-2Sn with 900<sup>o</sup>C solution treatment, phases formed were α-Zr and β-Zr and intermetallic Zr<sub>4</sub>Sn and SnTi<sub>3</sub> Zr-10Ti-4Sn alloys which were identified using X-Ray Diffraction (XRD).</p>

scholarly journals Mechanical properties and microstructure evolution of high-manganese (0.9 C – 13.95 Mn) steel during aging

2021 ◽  
Vol 297 ◽  
pp. 01044
Author(s):  
Omar Ben lenda ◽  
Sara Benmaziane ◽  
Ahmed Tara ◽  
Elmadani Saad
Keyword(s):  
Mechanical Properties ◽  
Hardness Test ◽  
Manganese Steel ◽  
X Ray Diffraction ◽  
High Manganese ◽  
High Manganese Steel ◽  
Influence Of Temperature ◽  
X Ray ◽  
Influence Of Temperature On ◽  
Mn Steel

The influence of temperature on the structural and mechanical properties of the (0.9 C - 13.95 Mn) steel was investigated in this work. The high-manganese steel has underwent aging treatments at temperatures 700, 750, 800 and 850 °C for different times. The experimental techniques used are hardness test, scanning electron microscopy, optical microscopy and X-ray diffraction. The mechanical behavior and microstructural evolution of the high-manganese steel during aging are almost the same. The aging of the high-manganese steel was characterized by a rapid hardening while the overaging by a slow softening. In aging, the dispersion of fine M7C3 carbides in the austenite led to an increase in hardness. In overaging, the softening was caused by the coarsening of the M7C3 carbides.

scholarly journals Effects of reverse cold rolling on the microstructure, texture and mechanical properties of AA1100 aluminium alloys

2021 ◽  
Vol 15 (2) ◽  
pp. 7983-7992
Author(s):  
Oswaldo Rivero ◽  
Diego Pico ◽  
Laura G Castruita ◽  
Francisco García-Pastor ◽  
Jimy Unfried
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cold Rolling ◽  
Tensile Test ◽  
Aluminium Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Deformation ◽  
Electron Scanning Microscopy ◽  
Back Scattering

In this work the microstructure, texture and mechanical properties during different stages of reverse cold rolling (RCR) process on aluminium alloy AA1100-H14 were analysed.  Microstructure was observed using optical and electron scanning microscopy. Texture was analysed using X-ray diffraction (macrotexture) and electron back-scattering diffraction (microtexture) techniques. Tensile test and microhardness measurements were carried out. Results showed that a high deformation using RCR was obtained in samples of annealed state leading to maximum values of tensile strength and hardness, along with a reduction of ductility. Intensity of -fibres decreased producing unstable textures {112} <110> while microstructure exhibited refinement of grain, with enlarged morphology.

Mechanical properties of FeAlSi powders prepared by mechanical alloying from different initial feedstock materials

2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Young’S Modulus ◽  
Milling Time ◽  
Young's Modulus ◽  
Element Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Particles ◽  
Complete Homogenization

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.

Micro-Hardness and Morphology of LDPE Influenced by Beta Radiation

2014 ◽  
Vol 606 ◽  
pp. 253-256 ◽  
Author(s):  
Martin Ovsik ◽  
Petr Kratky ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hardness Test ◽  
Polymer Materials ◽  
Beta Radiation ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Depth Sensing ◽  
Surface Layers ◽  
Hardness Values ◽  
Different Doses

This article deals with the influence of different doses of Beta radiation to the structure and mico-mechanical properties of Low-density polyethylene (LDPE). Hard surface layers of polymer materials, especially LDPE, can be formed by radiation cross-linking by β radiation with doses of 33, 66 and 99 kGy. Material properties created by β radiation are measured by micro-hardness test using the DSI method (Depth Sensing Indentation). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the LDPE tested. The highest values of micro-mechanical properties were reached at radiation dose of 66 and 99 kGy, when the micro-hardness values increased by about 21%. The changes were examined and confirmed by X-ray diffraction.

scholarly journals Enhancement of Chloroprene/Natural/Butadiene Rubber Nanocomposite Properties Using Organoclays and Their Combination with Carbon Black as Fillers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1085
Author(s):  
Patricia Castaño-Rivera ◽  
Isabel Calle-Holguín ◽  
Johanna Castaño ◽  
Gustavo Cabrera-Barjas ◽  
Karen Galvez-Garrido ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
High Performance ◽  
Rubber Matrix ◽  
Butadiene Rubber ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rubber Blends ◽  
Ft Ir ◽  
Chloroprene Rubber

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.

scholarly journals The Potential for Natural Stones from Northeastern Brazil to Be Used in Civil Construction

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 440
Author(s):  
Fabiana Pereira da Costa ◽  
Jucielle Veras Fernandes ◽  
Luiz Ronaldo Lisboa de Melo ◽  
Alisson Mendes Rodrigues ◽  
Romualdo Rodrigues Menezes ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Chemical Resistance ◽  
Mechanical Analysis ◽  
Northeastern Brazil ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Agents ◽  
Natural Stones

Natural stones (limestones, granites, and marble) from mines located in northeastern Brazil were investigated to discover their potential for use in civil construction. The natural stones were characterized by chemical analysis, X-ray diffraction, differential thermal analysis, and optical microscopy. The physical-mechanical properties (apparent density, porosity, water absorption, compressive and flexural strength, impact, and abrasion) and chemical resistance properties were also evaluated. The results of the physical-mechanical analysis indicated that the natural stones investigated have the potential to be used in different environments (interior, exterior), taking into account factors such as people’s circulation and exposure to chemical agents.

scholarly journals Functional Bionanocomposite Fibers of Chitosan Filled with Cellulose Nanofibers Obtained by Gel Spinning

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1563
Author(s):  
Sofia Marquez-Bravo ◽  
Ingo Doench ◽  
Pamela Molina ◽  
Flor Estefany Bentley ◽  
Arnaud Kamdem Tamo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Cellulose Nanofibers ◽  
Microstructural Characterization ◽  
Fiber Formation ◽  
Fiber Direction ◽  
Composite Fibers ◽  
X Ray Diffraction ◽  
Gel Spinning ◽  
X Ray

Extremely high mechanical performance spun bionanocomposite fibers of chitosan (CHI), and cellulose nanofibers (CNFs) were successfully achieved by gel spinning of CHI aqueous viscous formulations filled with CNFs. The microstructural characterization of the fibers by X-ray diffraction revealed the crystallization of the CHI polymer chains into anhydrous chitosan allomorph. The spinning process combining acidic–basic–neutralization–stretching–drying steps allowed obtaining CHI/CNF composite fibers of high crystallinity, with enhanced effect at incorporating the CNFs. Chitosan crystallization seems to be promoted by the presence of cellulose nanofibers, serving as nucleation sites for the growing of CHI crystals. Moreover, the preferential orientation of both CNFs and CHI crystals along the spun fiber direction was revealed in the two-dimensional X-ray diffraction patterns. By increasing the CNF amount up to the optimum concentration of 0.4 wt % in the viscous CHI/CNF collodion, Young’s modulus of the spun fibers significantly increased up to 8 GPa. Similarly, the stress at break and the yield stress drastically increased from 115 to 163 MPa, and from 67 to 119 MPa, respectively, by adding only 0.4 wt % of CNFs into a collodion solution containing 4 wt % of chitosan. The toughness of the CHI-based fibers thereby increased from 5 to 9 MJ.m−3. For higher CNFs contents like 0.5 wt %, the high mechanical performance of the CHI/CNF composite fibers was still observed, but with a slight worsening of the mechanical parameters, which may be related to a minor disruption of the CHI matrix hydrogel network constituting the collodion and gel fiber, as precursor state for the dry fiber formation. Finally, the rheological behavior observed for the different CHI/CNF viscous collodions and the obtained structural, thermal and mechanical properties results revealed an optimum matrix/filler compatibility and interface when adding 0.4 wt % of nanofibrillated cellulose (CNF) into 4 wt % CHI formulations, yielding functional bionanocomposite fibers of outstanding mechanical properties.

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