In pursuit of high thermal conductivity of SiC ceramics, this article reports the effects of AlN and sintering atmospheres on the thermal properties and microstructure evolution of SiC ceramics. Dense SiC ceramics with different contents of AlN additive were fabricated through hot-press sintering at 1950°C in Ar/N2 atmosphere under a pressure of 40 MPa for 3 h. The results showed that the thermal conductivity

With SiC as starting powder, waste fly ash as sintering additive and metal oxide as catalyst, mullite bonded SiC ceramic membrane was prepared at 1000°C using the conventional solid-state reaction method. Permeability parameters in both air and water flow tests were obtained using laboratory made set-up and the pure water permeability was measured at variable transmembrane pressures. The membrane exhibited

Nanocrystalline spinel forming precursor spinel hydrate (PSH), prepared by co-precipitation technique with controlled concentration of mixed salt, pH, temperature and time, was used as additive in calcined alumina-dead burnt magnesia (DBM) admixture to develop spinel (MgAl2O4) aggregates. Powder granulometry, mixing and dispersion of additive PSH were controlled during milling. Three batches of varying

Electrofilter powder (EP) is a residue generated in large amounts during the calcination of aluminium hydroxide in the Bayer process. The production of high temperature structural insulator (HTSI) using EP is proposed. Different tests were made using different proportions of the starting materials, although the optimal mixture contained (in wt%) 52% EP, 14.7% silica fume (or quartz), 12% refractory

The aim of this work is to study the effect of membrane thickness with respect to gas permeance and tensile strength. The influence of membrane thickness on gas permeation has received little attention to date. Single layer flat sheet membrane with average thickness of 25 μm and dual layer composite membranes with variable thickness of skin layer were fabricated by coating CA/ PEG selective layer on

Materials with high dielectric permittivity are in demand due to their potential applications in microelectronics, capacitors and related fields. Polymer/ceramic composites, due to their improved properties, can be studied to meet this demand. In this work, high permittivity double perovskite Sr2TiMnO6 (STMO) ceramics were synthesized by solid state reaction route and polystyrene (PS) composite thick

Two different coloured ceramic pigments, blue-green and black, were prepared by using solid phase reaction method from calcined leather waste and industrial grade metal oxides. Chemical compositions of leather waste were characterized by X-ray fluorescence (XRF) in order to determine their chemical compositions, which indicated that the calcined leather waste could be used as a chromium precursor system

Commercially procured magnesium aluminate (MgAl2O4) spinel powder with average particle size of 300 nm and irregular morphology were spray and freeze granulated. The granules were characterized for the texture, strength, granule size and its distribution. In order to evaluate the flowability of granules, rheological parameters, such as Carr index and Hausner ratio were measured. The granules were further

In the present study, we report the development of morphologically different copper and Cu(OH)2-Cu2O nanostructures by a single step chemical reduction method using ascorbic acid as environmental friendly reducing agent. Morphology and crystallographic patterns of the synthesized samples were analyzed using X-ray diffraction and scanning electron microscopy. Determination of catalytic performance of

In the present study, pristine magnesium aluminium layered double hydroxide (Mg-Al LDH, sample A) nanoparticles were synthesized by simple co-precipitation technique followed by intercalation of methotrexate drug (MTX), their detailed physicochemical characterization and development of RP-HPLC method for estimation of MTX intercalated in Mg-Al LDH nanoparticles (sample B). The PXRD analysis showed

A lead-free multiferroic double perovskite BiHoNiTiO6 (BHNT) was prepared at high temperature following mixed oxide solid state reaction mechanism. Structural evaluation by X-ray diffractogram suggested monoclinic crystal system for the BHNT. SEM images showed homogeneous morphology with almost similar and uniform grain distribution. The compound possessed low value of tanδ even at a high temperature

Bi0.9Nd0. 1Fe1–xCoxO3 (x = 0.025, 0.050, 0.075 and 0.1) solid solutions have been synthesized by doping of Co3+ at the Fe3+ site using solid-state reaction method. The prepared solid solutions have been investigated for their structural, magnetic, ferroelectric and magneto-dielectric properties and conduction mechanism. The XRD study reveals that all the solid solutions possess a rhombohedral symmetry

Radiation shielding window (RSW) glass for nuclear reactor is primarily required for protecting the operating personnel from harmful radioactive rays produced during nuclear energy generation in nuclear hot cells. In this respect, the production of high lead (>70% PbO) containing RSW glass is generally made using platinum pot through bottom pouring flow casting technique. However, owing to low capacity

ABSTRACT Laboratory synthesized (carbothermal-reduction-nitridation) 27R-SiAlON is studied in terms of crystallographic and microscopic features by detailed X-ray diffraction and electron microscopy experiments. 27R- SiAlON is analyzed to possess rhombohedral R3m structure and is best represented as Si1.1Al7.9O1.9N8.1. Lattice parameters, ion positions, bond lengths, angles as well as the crystallite

ABSTRACT A solution of Al(NO3)3.9H2O and NaOH was used to perform Mg-Al LDH plugging treatment on the LA103Z magnesium-lithium alloy micro-arc oxidation ceramic layer. The effect of treatment temperature on the micro-arc oxidation ceramic layer structure and corrosion resistance was studied. The formation mechanism of Mg-Al LDH film and corrosion mechanism of the film layer were discussed. The results

ABSTRACT Y(Lu)AG:Ce3+,Sm3+ yellow phosphors were prepared by molten salt method with 0.1NaCl-0.1KCl-0.8NaF as the molten salt. The effects of multi-factor variables on the properties of Y(Lu)AG:Ce3+,Sm3+ phosphors were comprehensively studied by orthogonal experiments which is a method to study the experiment with multi-factor variables and select some representative ones from the comprehensive experiment

ABSTRACT This work was carried out to establish a noble technique to enhance tribological characteristics of zirconia toughened alumina (ZTA) ceramic composite by adding 10 wt% nano CaF2 (∼50 nm) via chemical co-precipitation method. Result of the tribological tests, carried out using ball-on-disk tribo-pair in dry sliding, showed a considerable improvement in coefficient of friction up to ∼55% and

This article reviews different membrane processes for the removal of arsenic from groundwater. The source of arsenic and its toxic effects on human body are illustrated. Various membrane filtration processes like micro-filtration, nano-filtration, ultra-filtration and reverse osmosis are discussed. The materials used in different membrane techniques are highlighted towards the removal efficiency of

ABSTRACT In this work, we have reported the preparation of a flat circular ceramic membrane (53 mm diameter and 5 mm thick) by paste casting method from locally available Kashmir clay. The membrane was obtained by sintering the clay disc at 850oC for 5 h. The raw material and the membrane were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), Fourier

In the present work, yttrium orthovanadate (YVO4) nanopowder has been synthesized via solution combustion route using citric acid as fuel. The primary aim is to establish a facile solution combustion reaction to produce YVO4 nanopowder with lower band gap using vanadium pentoxide (V2O5.nH2O) gel as precursor and then investigation of its photocatalytic activity against anionic and cationic dyes in

Mullite ceramics was synthesized using boehmite (-AlOOH) as alumina source and polymethysilsesquioxanes (PMS), a novel class of preceramic polymer, as silica source. Quantitative mullitization was calculated from the X-ray diffractograms of powder samples of appropriate stoichiometry of the precursors calcined for various holding times between 1200o and 1300oC, using Rietveld analysis, and the kinetics

This study describes the microstructure, crystal structure, dielectric and piezoelectric behavior of 0.1Pb[Fe1/2Nb1/2]O3-0.9Pb[ZrxTi(1–x)]O3 (x = 0.49-0.55) ceramics synthesized by solid-state reaction. Compositions were sintered at 1180oC for 120 min. Dense and uniform microstructure was seen through microstructural analysis. XRD pattern confirmed the co-existence of tetragonal and rhombohedral perovskite

This study reported the effects of labware glass cullet on the properties of porcelain stoneware tiles. Five formulations of porcelain stoneware tiles (containing 0, 3, 6, 9, 12% borosilicate glass cullet) were prepared by adopting three different sintering temperatures (1100o, 1150o, 1200oC). The physical, microstructural and mechanical properties were analyzed. X-ray diffraction analysis ensured

Abstract MgAl2O4:M (M = Ti, Mn, Co, Ni) phosphors were successfully prepared by a modified polyacrylamide gel method. Calcination temperature and metal particle has significant effects on the phase transition, optical and color properties of Mg Al2O4: M phosphors. Ti, M n, Co and Ni metal particles introduced into the MgAl2O4 system can produce a variety of colours from white, grayish black, blue to

Based on the oxidation kinetics of C/SiC composites at 900o-1200oC in stress-oxidation environment, a non-uniform model of oxidation has been suggested in this paper. Combined with fiber notch model, Curtin’s strength model and BHE model, the non-uniform model is able to predict the failure time and residual strength of C/SiC composites accurately. Besides, the initial defects of the model (matrix

Abstract MgAl2O4:M (M = Ti, Mn, Co, Ni) phosphors were successfully prepared by a modified polyacrylamide gel method. Calcination temperature and metal particle has significant effects on the phase transition, optical and color properties of Mg Al2O4: M phosphors. Ti, M n, Co and Ni metal particles introduced into the MgAl2O4 system can produce a variety of colours from white, grayish black, blue to

The present work is based on investigation of mechanical behavior of green ceramic parts fabricated in scanning based ceramic microstereolithography (CM SL). This study is essential as many times green ceramic bodies fabricated by microstereolithography (MSL) can be directly incorporated in microelectromechanical systems (MEMS). These green parts are fabricated from ceramic suspensions obtained by

In this paper, a novel method of preparing porous alumina with alumina powder and boric acid is firstly proposed and experimented, and its mechanism of the fabricating process is also investigated. Unlike traditional methods of manufacturing porous alumina including electrochemical anodization of aluminium and chemical etching, ordered porous alumina has been directly fabricated through synthesis and

ABSTRACT Nanocrystalline boron carbide was synthesized using a precursor. The precursor was prepared by the thermal decomposition of a condensed product formed by boric acid and mannitol. The condensed product was formed by microwave-assisted heating of the aqueous solution of boric acid and mannitol. The condensed product was thermally decomposed at various temperatures, viz. 400°, 500° and 600°C

Abstract Ferroelectric ceramic compositions SrBi2–xYxNb2O9 (x = 0.0, 0.2, 0.4, 0.6 and 0.8) were prepared via conventional solid-state route with high density (92-99%) establishing the sintering conditions. X-ray diffraction studies confirmed the orthorhombic structure. The micrographs obtained from scanning electron microscopy showed the presence of well packed and randomly oriented needle-shaped

In this investigation, powder metallurgy route was employed to synthesize SiO2 (5, 10 and 15 vol%) coated aluminium borate whisker (ABOw) reinforced aluminium composites. Commercial pure aluminium powder was used as matrix material and SiO2 coated ABOw was used as reinforcements. M icrostructures of the composites were characterized using scanning electron microscopy and high resolution scanning electron

ABSTRACT To investigate the effect of synthesis approach on the structural and catalytic properties, CoAl2O4/CuFe2O4/CeO2/Ti O2 ceramic nanocomposite was synthesized by four liquid phase routes: mixing of components in the liquid phase ( method 1), mixing of CoAl2O4 precursor with other components (method 2), mixing of CoAl2O4 and CuFe2O4 precursors with other components ( method 3) and mixing of Cu

ABSTRACT With spalling and corrosion during thermal cycles, the castable composites used in injecting lance are easily damaged. In order to solve this problem, we used carbon fibers as additives in the matrix, and prepared mullite- based castables with the addition of anti-oxidant silicon. It was found that the addition of carbon fibers could significantly improve the mechanical properties; the maximum

The aim of the present investigation is to develop mechanochemically synthesized nano-crystalline hydroxyapatite (nHAp) bioceramics using clam seashells and phosphoric acid by varying the CaO:H3PO4 acid at different wt% ratios, i.e. 1:0.75, 1:1.0, 1:1.25, 1:1.5 and 1:1.75. The synthesized powders were characterized using X- ray diffraction ( XRD), scanning electron microscope and high resolution transmission

In order to improve the corrosion resistance of magnesium-lithium (Mg-Li) alloy, a micro-arc oxidation (MAO) ceramic layer was first prepared on LA103Z Mg-Li alloy, and then the MAO coating on LA103Z Mg-Li alloy was sealed by layered double hydroxide (LDH) hydrothermal treatment. The obtained samples were subjected to immersion test in 3.5% NaCl solution for 8 days. The growth characteristics of different

Determination of local atomic structure at nanoscale for both amorphous and nanocrystalline materials is very difficult and challenging. Local arrangement of atoms needs to be studied for understanding the local or short-range structural information. Pair distribution function (PDF) analysis is a technique used to study the short-range structure of the materials based on local atomic arrangement of

Alumina and monel superalloy was successfully joined by active metal brazing technique using Ticusil (68.8Ag-26.7Cu-4.5Ti in wt%) filler alloy in a vacuum furnace at 910°C for 10 min under a vacuum of 5×10–6 Torr. Phase analysis of the monel-filler alloy and alumina-filler alloy interfaces was conducted by X-ray diffraction analysis. Interfacial and cross-sectional microstructural investigation and

ABSTRACT Substitution in A or/and B sites of the perovskite lattice, or strain engineering is known to influence the properties of piezoelectric ceramics. Cerium (Ce) has been identified as a substituent to investigate the properties of lead-free (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 (BCZT) ceramics. Structural, ferroelectric, piezoelectric and dielectric properties of Ce substituted BCZT ceramics were investigated

ABSTRACT Dry sliding wear experiments were carried out at constant normal load and sliding speed on electrodeposited Ni and Ni-α-nano Al2O3 coatings. The coating surfaces were worn against EN-32 HRc hardened steel in pin-on-disc test rig. The work was concentrated on the pin temperature, frictional force and specific wear rate of the coating which were measured as the function of sliding distance.

Tribological behavior of hot pressed HfB2-5%TiSi2 composite was studied under reciprocative sliding condition using cemented tungsten carbide (WC-Co) ball as counter body. Coefficient of friction (COF) for HfB2 composite sample was obtained in the range of 0.43 to 0.63 at different loads. It was observed that enhancement of load from 5 to 15 N resulted in decrease of COF of HfB2. Specific wear rate

ABSTRACT A promising Aurivillius layered pervoskite ceramics, namely, the title compound has drawn interest in recent days owing to its figure of merit (magnetoelectric coupled properties). General formula of the compound is expressed as (Bi2O2)2+(A n–1 B nO3n+ 1)2–, where A represents Bi/Nd and B represents Ti/Fe/Co. However, no reports are available on impedance measurement of this compound. In the

Calcium phosphate is widely used as an implant material in the biomedical field, mainly because they are chemically similar to the inorganic components of bones. In many applications, dimensional accuracy is critical, and implants need to be shaped, sized and machined as needed. However, as ceramic materials with strong atomic bonding forces, they have high hardness and brittleness, so the ability

Nanocrystalline LiCoO2 particles have been surface modified with La2O3 by a simple and cost effective resin coating process. The synthesized pure and La2O3 coated samples were characterized by thermogravimetric analysis / differential scanning calorimetry (TGA/DSC), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron

ABSTRACT Based on the attribute of asbestos tailings rich in silicon and magnesium, the powder of asbestos tailings was pre-calcined followed by MgO addition in the green body and finally sintered to develop refractory ceramics containing phases of forsterite, magnesioferrite and merwinite. The effects of pre-calcining treatment, MgO content and sintering temperature on crystallization, phase transition

ABSTRACT XRD results show that diffraction peak of M3B is gradually apparent with the increase of annealing temperature and time, which indicates that annealing can promote the formation of M3B phase. The increase of annealing temperature and time leads to transformation of inter dendritic microstructure from long strip Cr3B phase to granular Cr3B phase. Particularly, after annealing at 1100oC for

ABSTRACT The aim of this investigation is to study the UV/Visible absorption and infra-red transmission characteristics due to Cu+/Cu2+ redox in silica glass. The glass composition 18Na2O-2MgO-8CaO-72SiO2 (mol%) containing different concentrations of CuO were prepared by melting route. The optical absorption spectra of the glasses were recorded on an UV/Visible/NIR spectrophotometer in the wavelength

ABSTRACT The work presented in this article deals with the synthesis of a cordierite ceramics, using a natural Algerian kaolin named DD3 of black colour, located in the region of Djbel Dbagh in Guelma. A synthesis was also carried out on bleached DD3 kaolin obtained by activation of hydrochloric acid on natural kaolin in order to eliminate the manganese oxide (which is responsible for the blackish

ABSTRACT Suitable sintering ability and excellent densification are important factors for forsterite (Mg2SiO4) ceramics and refractories when used in glass furnaces, continuous casting tundishes, non-ferrous metal smelters, etc. Here, a dense and fine-grained structure has been obtained in the forsterite ceramics prepared by two-step sintering process. Results show that combination of grinding and

ABSTRACT The influence of calcium bentonite addition on the compressive strength, efflorescence extent and drying shrinkage of fly-ash based geopolymer mortar was investigated. The results showed that appropriate amount (e.g. 15 wt%) of calcium bentonite addition favoured the enhancement of compressive strength mainly because its addition allowed the geopolymer to tolerate more water glass addition

ABSTRACT The effects of gamma irradiation in the dose rate of 25 kGy on the structural and optical properties of ZrO2 doped sodium borate glasses were studied. Glassy nature confirmed by XRD and all the physical parameters were calculated. IR spectra revealed the characteristic vibrational and stretching bands due to trigonal and tetrahedral borate network. Slight changes were caused by gamma irradiation

ABSTRACT To improve the corrosion resistance of the ceramic layer prepared by micro-arc oxidation (MAO) on magnesium alloy, a hydrophobic Mg-Al-Co layered double hydroxide (LDH) coating was fabricated on MAO coated AZ31 magnesium (Mg) alloy by using a simple in-situ growth method. The results showed that the LDH film covered the MAO coating tightly, and it sealed the micro-pores and cracks in the MAO

Eu3+ doped M3La2Si3O12 (M = Mg2+, Ca2+, Sr2+, Ba2+) materials were prepared using sol-gel technique. The samples were prepared at a temperature of 950oC using 0.01-0.05 mole of Eu3+ ion to examine worth of amount of activator ion on luminous intensity. Photoluminescence characteristics of these Eu3+ incorporated inorganic fluorescent materials were explored using photoluminescence (PL) emission spectroscopy

ABSTRACT High voltage bushing is one of the key components of Indian Test Facility. It is designed to provide 100 kV electrical isolation to all high voltage feedlines from the electrically grounded vessel. It also forms vacuum boundary between the vessel and the outer atmosphere. Conventional vacuum compatible porcelain insulator is selected for this purpose. However, to accommodate several high voltage

ABSTRACT Indian natural magnesite containing silica and lime as main impurities was beneficiated using reverse froth flotation technique. Pine oil was used as frother, Flotigam EDA as collector and sodium hexametaphosphate as depressant of carbonate group. Operating parameters were optimized using response surface methodology and a quadratic model equation was formulated for the experiment. The effect

Abstract High strength ceramic proppants are a significant factor during the hydraulic fracturing process. Although many system ceramic proppants have been developed, their strength remained relatively low. In this work high strength ceramic proppants have been successfully prepared by solid state sintering at 1450°C using low grade bauxite and varying contents of feldspar; XRD analysis revealed that

Abstract The present work reports a convenient way to evaluate the photocatalytic activity of anatase TiO2 films by monitoring the degradation of methylene blue (MB) directly on the TiO2 coated tiles under simulated solar light (1 sun condition; AM 1.5G simulator) using Raman spectroscopy. For this purpose, nanocrystalline TiO2 films of aesthetic quality (thickness ∼80±5 nm) were deposited by the sol-gel

ABSTRACT The present work is focused on the development and characterization of low-cost flat microfiltration ceramic membranes from West Cameroonian kaolin, cassava starch and bovine bone ash as pore-forming agents, and comparative study of porogens’ influence on membranes properties. These materials were chosen due to their abundance in the country and their beneficial properties. The proportion

Novel Eu3+ doped MGdAl3O7 (M = Mg, Ca, Sr and Ba) phosphors were synthesized and examined. The samples were prepared at 600°C using solution-combustion procedure and investigated at 0.01 to 0.05 mole of dopant ion concentration. The optimal concentration of Eu3+ ions was 0.03 mole for MGdAl3O7 host matrix. On 393 nm excitation, the materials exhibited sharp red emission at 608-614 nm because of 5D0

ABSTRACT Cleaning of coal resulted in ash reduction, heat value enhancement, increased reactive maceral content and change in ash composition influencing combustion performance. With washed fractions, trends of improved combustion behavior were observed in thermo-gravimetric analyser, which was not always reflected correspondingly in bench scale combustor, i.e. drop tube furnace (DTF). Lower burnout

ABSTRACT Dispersion of zirconia powder in aqueous suspension using suitable dispersant for coating application was studied. Zeta potential experiments were conducted in search of stable suspensions. Sedimentation tests were carried out in both acidic and basic pH range, i.e. from 2 to 11. Zirconia slurry as coating material was used for coating on clay-alumina tubular ceramic support. The slurry was