Contribution of the hybrid component to the structure and properties of ceramics based on metastable phases Al2O3

2021 ◽  
pp. 127-136
Author(s):  
A. V. Maletsky ◽  
T. E. Konstantinova ◽  
D. R. Belichko ◽  
G. K. Volkova ◽  
V. V. Burkhovetsky
Keyword(s):  
Mechanical Properties ◽  
Yttrium Aluminum Garnet ◽  
Metastable Phase ◽  
Physical And Mechanical Properties ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Mutual Inhibition ◽  
X Ray ◽  
Tetragonal Lattice ◽  
Yttrium Aluminum

The paper presents results of the study of the effect of doping with yttrium oxide on ceramics of the composition (γ + θ) Al2O3 + nY2O3 (n = 0, 1, 2, 3 wt%), sintered at 1550°C for 2 h, from powders of the specified composition annealed at temperatures of 500 , 800, 1000°С. X-ray diffraction analysis established the formation in ceramics of yttrium aluminum garnet Y3Al5O12 (YAG) and a metastable phase of the same composition with a tetragonal lattice type in powders at temperatures above 1200°C. The effect of YAG on the physical and mechanical properties was established: high properties were demonstrated by ceramics of the composition α-Al2O3 + 2wt% Y2O3, obtained from a powder annealed at 1000°C. In addition, high physical and mechanical properties were observed in ceramics of the composition α-Al2O3 + 0wt% Y2O3, obtained from a powder annealed at 800°C. The effect of the so-called “mutual protection against crystallization” was discovered, which consists in the mutual inhibition of crystallization processes in powders of the Al2O3 – Y2O3 system.

Physical and Mechanical Properties of Cement Paste Were Used Partially with Fly Ash and Kaolin Waste

2017 ◽  
Vol 866 ◽  
pp. 199-203
Author(s):  
Chidchanok Chainej ◽  
Suparut Narksitipan ◽  
Nittaya Jaitanong
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Room Temperature ◽  
Physical And Mechanical Properties ◽  
Partial Replacement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lime Water ◽  
Diffraction Patterns ◽  
Iron Mold

The aims of this research were study the microstructures and mechanical properties for partial replacement of cement with Fly ash (FA) and kaolin waste (KW). Ordinary Portland cement were partially replaced with FA and KW in the range of 25-35% and 10-25% by weight of cement powder. The kaolin waste was ground for 180 minutes before using. The specimen was packing into an iron mold which sample size of 5×5×5 cm3. Then, the specimens were kept at room temperature for 24 hours and were moist cured in the incubation lime water bath at age of 3 days. After that the specimens were dry cured with plastic wrap at age of 3, 7, 14 and 28 days. After that the compounds were examined by x-ray diffraction patterns (XRD) and the microstructures were examined by scanning electron microscopy (SEM). The compressive strength was then investigated.

scholarly journals Features of the hydration process of the modified blended cement for fiber cement panels

2018 ◽  
Vol 170 ◽  
pp. 03030 ◽  
Author(s):  
Rustem Mukhametrakhimov ◽  
Liliya Lukmanova
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Blended Cement ◽  
Physical And Mechanical Properties ◽  
Hydration Process ◽  
Cement Matrix ◽  
X Ray Diffraction ◽  
Structure Form ◽  
Silicate Phase ◽  
X Ray

The paper studies features of the hydration process of the modified blended cement for fiber cement panels (FCP) using differential thermal analysis, X-ray diffraction analysis, electron microscopy and infrared spectroscopy. It is found that deeper hydration process in silicate phase, denser and finer crystalline structure form in fiber cement matrix based on the modified blended cement. Generalization of this result to the case of fiber cement panels makes it possible to achieve formation of a denser and homogeneous structure with increased physical and mechanical properties.

Phase selection in precursor-derived yttrium aluminum garnet and related Al2O3–Y2O3 compositions

2005 ◽  
Vol 20 (4) ◽  
pp. 1017-1025 ◽  
Author(s):  
Ashutosh S. Gandhi ◽  
Carlos G. Levi
Keyword(s):  
Heat Treatment ◽  
Yttrium Aluminum Garnet ◽  
Lattice Parameter ◽  
Defect Structures ◽  
X Ray Diffraction ◽  
Phase Selection ◽  
X Ray ◽  
Yttrium Aluminum ◽  
Rich Side ◽  
Nitrate Solutions

Al2O3–Y2O3 powders were synthesized in the range of 25–55% Y2O3 by reverse coprecipitation of nitrate solutions. All starting powders were amorphous and formed primary yttrium aluminum garnet (YAG) upon crystallization. X-ray diffraction detected only garnet in compositions of 30–40% Y2O3 after heat treatment at 1250 °C. Compositions of 45–55% Y2O3 established a metastable YAG + Y4Al2O9 microstructure. The YAG phase field was metastably extended away from its stoichiometry, as indicated by a systematic increase in lattice parameter with Y2O3 content. Although some Al2O3 enrichment was achieved, YAG appears to tolerate greater off-stoichiometry on the Y2O3-rich side. Possible defect structures accommodating the solubility extension were examined. Phase selection results indicate that compositional inhomogeneity is not the only reason behind the appearance of hexagonal YAlO3, which is frequently reported during YAG synthesis.

Structure and properties of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/poly(L-lactic acid) quasi core/sheath melt-electrospun microfibers

2018 ◽  
Vol 89 (9) ◽  
pp. 1770-1781 ◽  
Author(s):  
Huaizhong Xu ◽  
Benedict Bauer ◽  
Masaki Yamamoto ◽  
Hideki Yamane
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Lactic Acid ◽  
Tensile Tests ◽  
Processing Parameters ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Diffraction Patterns

A facile route was proposed to fabricate core–sheath microfibers, and the relationships among processing parameters, crystalline structures and the mechanical properties were investigated. The compression molded poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH)/poly(L-lactic acid) (PLLA) strip enhanced the spinnability of PHBH and the mechanical properties of PLLA as well. The core–sheath ratio of the fibers was determined by the prefab strip, while the PLLA sheath component did not completely cover the PHBH core component due to the weak interfacial tension between the melts of PHBH and PLLA. A rotational target was applied to collect aligned fibers, which were further drawn in a water bath. The tensile strength and the modulus of as-spun and drawn fibers increased with increasing the take-up velocities. When the take-up velocity was above 500 m/min, the jet became unstable and started to break up at the tip of the Taylor cone, decreasing the mechanical properties of the fibers. The drawing process facilitated the crystallization of PLLA and PHBH, and the tensile strength and the modulus increased linearly with the increasing the draw ratio. The crystal information displayed from wide-angle X-ray diffraction patterns and differential scanning calorimetry heating curves supported the results of the tensile tests.

Physical and Mechanical Properties of Bi0.5(Na0.81K0.19)0.5TiO3 Ceramic Modified by KNbO3

2019 ◽  
Vol 805 ◽  
pp. 71-75
Author(s):  
Suchittra Inthong ◽  
Chatchai Kruae-In ◽  
Wuttikrai Thanomsiang ◽  
Suppanat Kosolwattana ◽  
Denis Russell Sweatman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mixed Oxides ◽  
Perovskite Phase ◽  
Physical And Mechanical Properties ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
X Ray ◽  
Ceramic Samples ◽  
Pure Phase ◽  
Knoop Microhardness

This research reports the physical and mechanical properties of (1-x) Bi0.5(Na0.81K0.19)0.5TiO3-xKNbO3 (x=0.00-0.06) ceramics. The Modified Bi0.5(Na0.81K0.19)0.5TiO3 ceramics were synthesized by solid state reaction technique. The mixed oxides powders were calcined at 850 °C, 4 h and sintered at 1120 °C, 2 h to form pure phase perovskite and the optimum bulk density, respectively. The phase formation of the modified ceramic samples was determined by X-ray diffraction technique. All of the modified Bi0.5(Na0.81K0.19)0.5TiO3 ceramics exhibited a single perovskite phase. The bulk densities of the modified ceramic samples were 5.41±0.27-5.75±0.28 g/cm3 using the Archimedes’ method. The microstructure was revealed by the scanning electron microscope. The rectangular-like shape was found of all studied ceramics which had the grain size between 1.31±0.02-1.56±0.03 mm. The mechanical properties were studied by both Vickers and Knoop microhardness tester. The results are discussed in term of the relation among hardness properties, Young’s modulus, and fracture toughness.

SYNERGISTIC REINFORCEMENT OF ORGANOCLAY AND DOUBLE NETWORKING IN NATURAL RUBBER

2013 ◽  
Vol 86 (2) ◽  
pp. 205-217 ◽  
Author(s):  
Hedayatollah Sadeghi Ghari ◽  
Zahra Shakouri
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Natural Rubber ◽  
Physical And Mechanical Properties ◽  
X Ray Diffraction ◽  
Double Network ◽  
X Ray ◽  
Extension Ratio ◽  
Curing Characteristics ◽  
Scanning Electron

ABSTRACT Research was undertaken on natural rubber (NR) nanocomposites with organoclays. A double-network (DN) structure is formed when a partially cross-linked elastomer is further cross-linked during a state of strain. Two methods were used in the preparation of NR/organoclay nanocomposites: the ordinary method (single-network NR nanocomposite) and double-networked NR (DN-NR) nanocomposites. The single-networked NR nanocomposites were used for comparison. The effects of organoclay (5 phr) with a different extension ratio on curing characteristics, mechanical properties, hardness, swelling behavior, and morphology of single- and double-networked NR nanocomposites were studied. The results showed that double-networked NR nanocomposites exhibited higher physical and mechanical properties. The tensile strength of DN-NR nanocomposites increased up to 33 MPa (more than four times greater than that of pure NR) and then decreased with an increasing extension ratio. Modulus and hardness continuously increased with an increased extension ratio. The microstructure of the NR/organoclay systems was studied by X-ray diffraction and field emission scanning electron microscopy. The effects of different extension ratios on the dispersion of organoclay layers in the nanocomposites were investigated. Generally, results showed that the optimized extension ratio in DN nanocomposites was equal (or about or around) to α= 2.

scholarly journals Investigation of deformation and microstructure of bainite in Cu-9.97%Al-4.62%mn alloy

2014 ◽  
Vol 50 (1) ◽  
pp. 87-90 ◽  
Author(s):  
E. Aldirmaz ◽  
I. Aksoy
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Physical And Mechanical Properties ◽  
Compression Stress ◽  
X Ray Diffraction ◽  
Deformation Effect ◽  
X Ray ◽  
Deformation Test ◽  
Scanning Electron

In this study, some physical and mechanical properties in Cu-9.97%Al-4.62%Mn (wt%) alloy were investigated by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and compression deformation test. Bainite phase were obtained in the samples according to SEM and XRD analyses. Compression stress was applied on the alloy in order to investigate the deformation effect on the bainite phase transformation. On the surface of the Cu-9.97%Al-4.62%Mn alloy after the deformation, both bainite and martensite variants formed.

Physical and Mechanical Properties of Glass Composite Material Made from Incinerated Scheduled Waste Slag and SLS Waste Glass

2012 ◽  
Vol 626 ◽  
pp. 280-288 ◽  
Author(s):  
Jariah Mohd Juoi ◽  
Dilip Arudra ◽  
Zulkifli Mohd Rosli ◽  
A.R. Toibah ◽  
Siti Rahmah Shamsuri ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Water Absorption ◽  
Physical And Mechanical Properties ◽  
Waste Glass ◽  
X Ray Diffraction ◽  
Glass Composite ◽  
X Ray ◽  
Land Site ◽  
Waste Loading

Incineration of scheduled waste and landfilling of the incineration residue (Bottom Slag) is extensively practised in Malaysia as a treatment method for scheduled waste. Land site disposal of Bottom Slag (BS) may lead to environmental health issues and reduces the availability of land to sustain the nations development. This research aims in producing Glass Composite Material (GCM) incorporating BS and Soda Lime Silicate (SLS) waste glass as an alternative method for land site disposal method and as an effort for recycling SLS waste glass .SLS waste glass originates from the urban waste and has been a waste stream in most of the nation whereby the necessity for recycling is in high priority.The effect of BS waste loading on the GCM is studied.Batches of powder mixture is formulated with 30 wt% to 70 wt % of BS powder and SLS waste glass powder for GCM sintering.The powder mixtures of BS and SLS waste glass is compacted by uniaxial pressing method and sintered at 800C with heating rate of 2C/min and 1 hour soaking time. Physical analysis of bulk density, apparent porosity, and water absorption is perfomed according to ASTM C-373 standard. Mechanical testing of microhardness vickers according to ASTM C1327 and Modulus of Rupture (MOR) according to ISO 10545-4 is conducted. Microstructural analysis is carried out using Scanning Electron Microscope and phase analysis by X-ray diffraction method.Phases identified are Anorthite sodian,Quartz,Hematite and Diopside from X-ray diffraction analysis. Higher BS waste loading shows weak physical and mechanical properties .GCM from batch formulation of 30 wt % BS and 70 wt% SLS waste glass has projected optimized physical and mechanical properties. It is observed this batch has projected lowest water absorption percentage of 1.17 % , lowest porosity percentage of 2.2 %, highest bulk density of 1.88 g/cm3and highest MOR of 70.57 Mpa and 5.6 GPa for Vickers Microhardness.

Study on Physical and Mechanical Properties of Cu/MoS2 Composites

2013 ◽  
Vol 575-576 ◽  
pp. 156-159
Author(s):  
Dou Qin Ma ◽  
Jing Pei Xie ◽  
Ji Wen Li ◽  
Ai Qin Wang ◽  
Wen Yan Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Diffraction Analysis ◽  
Electric Conductivity ◽  
Hot Pressing ◽  
Physical And Mechanical Properties ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vacuum Hot Pressing

Cu-3wt. %MoS2-7wt. %Mo and Cu-3wt. %MoS2 composites were prepared by repressing, re-sintering and vacuum hot pressing, respectively. Microstructures were characterized by optical metallographic microscope, EDS, SEM and X-ray diffraction analysis, respectively. The micro hardness, electric conductivity and density of samples were separately measured as well. Results show that the micro hardness of Cu-3wt. % MoS2-7wt. % Mo composites is about 33.3% higher than that of Cu-3wt. %MoS2 composites. The increase in micro hardness is attributed to the presence of Mo. The electric conductivity of Cu-3wt. %MoS2 and Cu-3wt. %MoS2-7wt. % Mo prepared by vacuum hot pressing were 80.6 % and 63.8% IACS, respectively, which is an increase compared with values of 80.2 % and 57.3% IACS of samples obtained by repressing and re-sintering.

scholarly journals Geomechanical characterization of lateritic hardpans from Bamendjou (West-Cameroon)

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Y. Ngueumdjo ◽  
V. H. Njuikom Djoumbi ◽  
V. Y. Katte ◽  
F. Ngapgue ◽  
A. S. L. Wouatong
Keyword(s):  
Mechanical Properties ◽  
Specific Gravity ◽  
Physical And Mechanical Properties ◽  
Western Region ◽  
Geochemical Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Geomechanical Characterization

AbstractThis study reports on the physical, mechanical, mineralogical and geochemical analysis carried out on four lateritic hardpan specimens from quarries in the Bamendjou area in the Western Region of Cameroon using common prescribed procedures. The results indicate that values of the bulk density, specific gravity, total and open porosities are very variable from one specimen to another. Meanwhile, the value of the compressive strengths of both the dry and immersed specimens were also very variable from one specimen to another, with the F2 and F1 specimens having higher values than the A1 and A2 specimens. All the specimens immersed in water recorded lower compressive strengths than the dry specimens. The flexural strengths also varied from one sample to another, with the F2 specimen having the highest resistance. The X-ray diffraction patterns reveal that the major peaks were assigned to gibbsite, goethite, and hematite, while the minor peaks were assigned to kaolinite and anatase. The mineralogy and geochemistry influenced the physical and mechanical properties, with the iron rich specimens having higher values in both the physical and mechanical properties than the alumina rich specimens. The results of the compressive strengths obtained were higher than (1–4) MPa obtained in Burkina Faso and India where they have been using latertic blocks for construction. Thus the hardpans of Bamendjou can also be exploited for building purposes conveniently.

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