Showing papers in "Advances in Applied Ceramics in 2006"
TL;DR: In this article, the basic principles of incorporating high level radioactive waste into glasses, ceramics and glass composites, including glass-ceramics, are described, and the importance of processing property-structure relations in such systems over size scales from the atomic to the geological and on timescales to hundreds of thousands of years is highlighted.
Abstract: The basic principles of incorporating high level radioactive waste into glasses, ceramics (Synroc type) and glass composites including glass ceramics are described. Current UK technology uses glass wasteforms for the products of reprocessing, although many countries are temporarily storing the ceramic spent fuel for eventual disposal. Some waste streams may be incorporated into ceramics, but difficult or legacy wastes will require the development of other wasteforms comprising composite systems of crystals and glass. The importance of processing–property–structure (especially durability) relations in such systems over size scales from the atomic to the geological and on timescales to hundreds of thousands of years is highlighted.
331 citations
TL;DR: In this article, a powder sintering route with the incorporation of 2 wt-%SiC as foaming agent was used to produce lightweight glass ceramic foams from a mixture of silicate wastes.
Abstract: Lightweight glass ceramic foams have been produced from a mixture of silicate wastes, namely 20 wt-% coal pond ash and 80 wt-% bottle glass cullet. A powder sintering route with the incorporation of 2 wt-%SiC as foaming agent was used. The pore morphology achieved under different sintering conditions was investigated in detail using X-ray microtomography. The apparent density of the foams ranged from 0·2 to 0·4 g cm−3, and the porosity ranged from 70 to 90%. Other variables, such as pore wall thickness, pore size and roundness, all behaved consistently with sintering temperature. The optimum sintering temperature was found to be in the range 1000–1050°C, at which porosity was about 75% and was the most uniform. Foams produced under this condition exhibit satisfactory compressive strength of about 1·5 MPa and show relatively high thermal shock resistance, with compressive strength gradually decreasing as quenching temperature increases.
94 citations
TL;DR: In this paper, texture engineering using reactive-templated grain growth (RTGG) is reviewed as a key processing technique for lead free piezoelectric ceramics.
Abstract: Texture engineering using reactive-templated grain growth (RTGG) is reviewed as a key processing technique for lead free piezoelectric ceramics. Bismuth layer structured ferroelectric ABi4Ti4O15 (A=Na0·5Bi0·5, Ca, Sr) ceramics with a highly preferred {001} orientation were fabricated with enhanced piezoelectric properties using Bi4Ti3O12 platelets. Textured simple perovskite type ceramics were also prepared in Bi0·5Na0·5TiO3 (BNT), BaTiO3 and K0·5Na0·5NbO3 (KNN) based compositions with Lotgering's factor higher than 0·8. The textured BNT and KNN based ceramics exhibited enhanced electromechanical coupling coefficients and piezoelectric constants when compared with their randomly oriented counterparts. The development of microstructure and texture in the RTGG processed ceramics is dependent on the target system, starting materials and processing parameters, and optimum preparation conditions must be found by analytical investigation.
90 citations
TL;DR: In this paper, the authors review the literature pertaining to waste vitrification in terms of legislation, waste compositions, energy, emissions and economic assessments and conclude that the high compositional variability of these and other wastes tends to preclude their use in many applications.
Abstract: Whilst the vitrification of waste materials is a well established technology, hitherto it has not been economically viable on any substantial scale when applied to non-radioactive wastes. However new UK and European legislation may affect this situation. The present paper briefly reviews published work pertaining to waste vitrification in terms of legislation, waste compositions, energy, emissions and economic assessments. The focus is on vitrification of ashes arising from the incineration of municipal solid waste (MSW) and sewage sludge in terms of their composition, glass melting and reuse potential. The conclusion is that the high compositional variability of these and other wastes tends to preclude their use in many applications. However, the use of modern sorting and separation technology coupled with better control of waste treatment procedures may help to improve the range of potential uses for these wastes.
83 citations
TL;DR: Pastes of pulverised fly ash (PFA) and blast furnace slag (BFS) were chemically activated using sodium silicate with modulus (SiO2/Na2O... as discussed by the authors ).
Abstract: Pastes of pulverised fly ash (PFA) and blast furnace slag (BFS) in proportions of 100–0, 75–25, 50–50, 25–75 and 0–100 (wt-%) were chemically activated using sodium silicate with modulus (SiO2/Na2O...
77 citations
TL;DR: In this paper, the authors present the reasoning behind the use of phase diagrams to guide ceramic production, namely the assumptions necessary in making educated choices of compositions and processing parameters, and show how adequate dexterity with the diagrams' basic rules and dictates, coupled with sound knowledge of ceramic science and processing, can save time and resources.
Abstract: While natural raw materials are becoming scarce and in some cases approach exhaustion, continuous industrial activity generates increasing quantities of wastes and subproducts, whose disposal is subject to ever stricter environmental legislation. Some wastes are similar in composition to the natural raw materials used in the fabrication of ceramics and often contain materials that are also beneficial in the fabrication process. Thus, upgrading industrial wastes to alternative raw materials is of interest both technically and economically. The present paper sets out the reasoning behind the use of phase diagrams to guide ceramic production, namely the assumptions necessary in making educated choices of compositions and processing parameters. It goes on to show how adequate dexterity with the diagrams' basic rules and dictates, coupled with sound knowledge of ceramic science and processing, can save time and resources, and eventually lead to successful upgrading of the waste material and ameliorati...
70 citations
TL;DR: In this article, the authors describe some of the interactions that can occur within Portland cement based systems and highlight the fact that to achieve successful encapsulation of a wide range of waste types that make up the legacy or historic wastes present in the UK, a toolbox or formulary of different cement systems with differing chemistries is needed.
Abstract: Reactions that occur between a radioactive waste and a cement matrix being used for encapsulation can compromise the integrity of the resulting wasteform. The present paper describes some of the interactions that can occur within Portland cement based systems. It highlights the fact that to achieve successful encapsulation of the wide range of waste types that make up the legacy or historic wastes present in the UK, a toolbox or formulary of different cement systems with differing chemistries is needed. Some potential alternative cement systems are discussed.
68 citations
TL;DR: Raman spectroscopy has been used to follow the hydration of C3A and C4AF, two of the principal components of ordinary Portland cement (OPC), in the absence and presence of calcium sulphate (gypsum).
Abstract: Raman spectroscopy has been used to follow the hydration of C3A and C4AF, two of the principal components of ordinary Portland cement (OPC), in the absence and presence of calcium sulphate (gypsum). Raman spectroscopy enabled in situ, real time analysis of the hydrating pastes. Analysis of the pastes by X-ray diffraction complemented the Raman data and confirmed sample composition. Subtle changes in the Raman spectra of the different pastes illuminated differences in hydration behaviour between C3A and C4AF. The similarities and differences between the various systems are discussed. The influence of carbon dioxide on the hydration products has also received attention.
65 citations
TL;DR: In this article, a review of the developments in the fields of bioceramic materials and laser surface microstructuring of materials is presented, with the advantages of producing nanocrystalline material via emulsion routes.
Abstract: The present paper reviews the developments in the fields of bioceramic materials and laser surface microstructuring of materials. The clinical success of a bioceramic implant depends largely on the biological response at the implant interface in addition to the sufficiency of the mechanical properties for the application. The use of lasers in the present paper is largely to tailor the topography, surface properties and composition with a view to enhancing the implant biocompatibility. Developments in production methods for hydroxyapatite [HA: Ca10(PO4)6(OH)2] are also discussed with the advantages of producing nanocrystalline material via emulsion routes. The improved mechanical stability featured by nanocrystalline HA should promote clinical success in further load bearing applications.
63 citations
TL;DR: In this paper, the development of robust methods for determining fracture toughness and for interlaboratory assessment of results is discussed with respect to procedural standardisation, and the four simplest methods meeting these criteria are reviewed in detail, together with information on their reproducibility gathered during international round robin exercises.
Abstract: The development of robust methods for determining fracture toughness and for interlaboratory assessment of results is discussed with respect to procedural standardisation. Acceptable methods are based on meeting several criteria, including ease and cost-effectiveness of testpiece manufacture, the method of introducing a sharp precrack and the acceptability of appropriate fracture toughness analysis. The four simplest methods meeting these criteria are reviewed in detail, together with information on their reproducibility gathered during international round robin exercises. Not all these methods are effective on all materials, and users need to be aware of their limitations. Details of calibration equations and some experimental nuances are given.
58 citations
TL;DR: The corrosion of aluminium produced an interface between aluminium and cement which was porous with a series of zones containing bayerite (Al(OH)3) and stratlingite (2CaO.Al2O3.SiO2.8H2O) as mentioned in this paper.
Abstract: Legacy radioactive wastes arising from reprocessing of nuclear fuels in the UK are classified as intermediate level waste (ILW), which contain things such as aluminium and magnesium. Blast furnace slag (BFS) composite cements are used to encapsulate ILW. These cements have a high pH which is advantageous to limit the mobility of some of the radioactive species but can cause corrosion of metals. The present paper describes some fundamental aspects of corrosion of aluminium and magnesium in BFS composite cements.The corrosion of aluminium produced an interface between aluminium and cement which was porous with a series of zones containing bayerite (Al(OH)3) and stratlingite (2CaO.Al2O3.SiO2.8H2O). With magnesium, the main corrosion product was found to be brucite (Mg(OH)2) and the porous zone was less pronounced. The hydration of the bulk cement did not appear to be affected by the corrosion of these metals.
TL;DR: In this paper, a new composite armour system consisting of a ceramic plate, an intermediate ceramic-polymer layer and a polymer fibre lining as a backing material was developed and ballistically tested.
Abstract: The development of lightweight armour systems for ballistic protection is under continuing attention of the manufacturers and users. A new design of the composite armour systems has been developed and ballistically tested. A new armour system consists of a ceramic plate, an intermediate ceramic–polymer layer and a polymer fibre lining as a backing material. The proposed composite armour systems prepared with a use of specially selected compositions of the intermediate layer promoting the absorption of the kinetic energy of projectiles provide adequate ballistic protection to National Institute of Justice (NIJ) level III and level IV, and they successfully withstand multiple hits.
TL;DR: Ceramic pigments based on the perovskite structure develop a promising red hue and furthermore present no environmental or health problems as mentioned in this paper. But their efficiency was tested in different cera...
Abstract: Ceramic pigments based on the perovskite structure develop a promising red hue and furthermore present no environmental or health problems. Pigment colouring efficiency was tested in different cera...
TL;DR: In this article, the microstructure development during surface modifications of alumina ceramic using high power continuous wave Nd:YAG laser was discussed and the microstructural observations can be used to establish the guidelines for optimising the laser fluence to achieve the desired morphology of the surface grains and extent of texture in the surface modified alumina ceramics.
Abstract: The present study discusses the microstructure development during surface modifications of alumina ceramic using high power continuous wave Nd:YAG laser. Laser fluence influenced the microstructure in terms of changes in morphology and (1 1 0) crystallographic texture of the surface grains. The microstructural observations can be used to establish the guidelines for optimising the laser fluence to achieve the desired morphology of the surface grains and extent of texture in the surface modified alumina ceramic.
TL;DR: In this paper, the possibility of recycling scrap glass (soda lime, lead and barium based glasses) by incorporation into a porcelain stoneware tile mix was examined, and several modified mixes were prepared by replacing different amounts of the fluxing component, a sodium feldspathic sand, with three types of scrap glass: a soda lime glass from urban wastes, a lead based glass from the neck part of cathode ray tubes (CRTs), and a barium-based glass from CRT panels.
Abstract: The possibility of recycling scrap glass (soda lime, lead and barium based glasses) by incorporation into a porcelain stoneware tile mix has been examined. Starting from a standard porcelain stoneware body mix, several modified mixes were prepared by replacing different amounts of the fluxing component, a sodium feldspathic sand, with three types of scrap glass: a soda lime glass from urban wastes, a lead based glass from the neck part of cathode ray tubes (CRTs), and a barium based glass from CRT panels. The replacement of feldspar sand with a soda lime scrap glass, in the range 5–10 wt-%, allows porcelain stoneware materials to be obtained with good characteristics. A slight decrease in the water absorption of the fired material is observed after sintering at the same temperature as the reference mix. Furthermore, flexural strength remains high and the microstructural homogeneity enhances reliability. The presence of 2 and 5 wt-%, of lead and barium based scrap glass respectively, both character...
TL;DR: In this paper, the results of an investigation into the use of cement kiln dust and fly ash as a new cementitious material were presented, and the activation process chosen, in order to facilitate and enhance hydration of the two materials, was mechanochemical activation.
Abstract: This paper presents the results of an investigation into the use of cement kiln dust and fly ash as a new cementitious material. The activation process chosen, in order to facilitate and enhance hydration of the two materials, was mechanochemical activation. Activation is accomplished through the use of attrition mill. The two materials were combined and subjected to various grinding regimes to cultivate mechanochemical activation. Activation was determined through the use of particle size distribution and X-ray diffraction testing. Properties of the cementitious paste were determined by heat of hydration and compressive strength testing of cubes. The results indicate that separate grinding of the two materials is more effective at activating the materials and provide the best properties of the paste.
TL;DR: In this paper, a composite layered system based on monolithic armour ceramic tiles joined with polymer infiltrated ceramic foams has been designed and evaluated for lightweight ballistic protection, taking into account morphological characteristics and main physical properties of the materials used (facing ceramic tile, ceramic foam and polymers).
Abstract: Armour systems require advanced solutions, relying on a combination of materials of different natures to provide adequate ballistic protection and weight saving. For the first time in the present study composite layered systems based on monolithic armour ceramic tiles joined with polymer infiltrated ceramic foams have been designed and evaluated for lightweight ballistic protection. Open cell silicon carbide foams of various cell sizes infiltrated with thermosetting or elastomeric polyurethane were used for this design. The ballistic test results are discussed taking into account the morphological characteristics and main physical properties of the materials used (facing ceramic tile, ceramic foam and polymers), as well as test conditions. The proposed design may be considered for structural and vehicular protection solutions, including blast protection.
TL;DR: In this article, ZnO varistor materials were prepared by a sol gel route with subsequent drying and calcination, and the results were compared with commercial varistor samples sintered in a similar way.
Abstract: ZnO varistor materials were prepared by a sol gel route with subsequent drying and calcination. Varistor discs fabricated from these materials were subjected to a two step sintering schedule. Therefore in a typical experiment, the samples were heated to 1000°C, then allowed to cool for over 30 min to 900°C and held there for 6 h. The results were compared with commercial varistor samples sintered in a similar way. Considerably higher breakdown voltages were obtained for the varistors made from nanosample (1192±30 V mm−1) compared with the commercial samples (723±30 V mm−1) sintered under the same experimental conditions. The sintered materials were characterised by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and density measurements.
TL;DR: In this paper, a polycrystalline sample of Pb2Bi3SmTi5O18, a member of tungsten-bronze (TB) family, was prepared using a high temperature solid state reaction technique.
Abstract: Polycrystalline sample of Pb2Bi3SmTi5O18, a member of tungsten–bronze (TB) family, was prepared using a high temperature solid state reaction technique. X-ray diffraction (XRD) analysis indicated the formation of a single phase orthorhombic structure. AC impedance plots were used as a tool to analyse the electrical behaviour of the sample as a function of frequency at different temperatures. The ac impedance studies revealed the presence of grain boundary effect, from 350°C onward. Complex impedance analysis indicated non-Debye type dielectric relaxation. The Nyquist plot showed the negative temperature coefficient of resistance (NTCR) character of Pb2Bi3SmTi5O18. AC conductivity data were used to evaluate the density of states at Fermi level and activation energy of the compound.
TL;DR: In this article, a graphite crucible was used to produce a boron carbide powder using commercial purity raw materials, which contained 0·75 and 0·65 wt-% free carbon respectively.
Abstract: Carbothermic reduction process is recognised as a beneficial method to produce boron carbide powder. In the present article, this method was utilised to produce a boron carbide powder using commercial purity raw materials. Boron oxide being a source of boron and carbon active and petroleum coke as reducing agents were used. Mixtures of boron oxide and carbon holding material with a particle size of <44 μm were put in a graphite crucible and heated under a flow of argon atmosphere in a tube furnace to 1400–1550°C for 1–5 h, resulting in the formation of boron carbide powder with or without unreacted starting raw materials. It was found that the optimum weight ratio of boron oxide to carbon bearing material was 1·8 and 1·6 for petroleum coke and carbon active respectively. Heat treatment of these mixtures at 1470°C for 5 h resulted in the synthesis of boron carbide powders, which contained 0·75 and 0·65 wt-% free carbon respectively.
TL;DR: In this paper, the influence of MgO addition and sintering parameters on the formation and densification of mullite was investigated by means of a scanning electron microscope, where the morphology of powders and the microstructure of the sintered samples were characterised by using X-ray diffraction.
Abstract: In the present work, the influence of MgO addition and sintering parameters on the formation and densification of mullite was investigated. The morphology of powders and the microstructure of the sintered samples were characterised by means of a scanning electron microscope. X-ray diffraction was used to characterise phases formed in sintered samples. The density of sintered samples was measured using a densimeter and quantified according to the Archimedes principle. MgO was added at 1, 2, 3, 4, 5 and 6 wt-% to kaolin and alumina and the powders were ball milled for 5 h then uniaxially compacted at 75 MPa and finally sintered at 1500, 1550, 1600 and 1650°C for 2, 4, 6 and 8 h. It was found that addition of MgO not only affected mullite formation but also promoted grain growth. For samples containing 0, 1 and 2 wt-%MgO only mullite was formed. While, in addition to mullite, Al2O3 was present in sample containing 3 wt-%MgO. At higher MgO content (4, 5 and 6 wt-%), three phases, i.e. mullite, Al2O3 a...
TL;DR: In this article, a new polycrystalline layered ceramic oxide, LiFeVO4, has been prepared by a standard solid state reaction technique using thermogravimmetric analysis (TGA) technique.
Abstract: A new polycrystalline layered ceramic oxide, LiFeVO4, has been prepared by a standard solid state reaction technique. The preparation conditions were optimised using thermogravimmetric analysis (TGA) technique. Material formation under the reported conditions was confirmed by X-ray diffraction studies. A preliminary structural analysis indicated that the crystal structure was orthorhombic with lattice parameters: a=4·3368 A, b=13·1119 A and c=16·3426 A. The phase morphology and surface property were studied by scanning electron microscopy. Complex impedance analysis of the sample indicated bulk contribution to electrical properties at T≤125°C, grain boundary effects at the temperatures ≥125°C, negative temperature coefficient of resistance (NTCR) effect and evidence of temperature dependent electrical relaxation phenomena in the sample. The dc conductivity σdc shows typical Arrhenius behaviour when observed as a function of temperature. The activation energy value was estimated to be 0·24 eV. The...
TL;DR: Bypass cement dust from the Rabigh plant in Saudi Arabia was examined for use in the preparation of technical coloured glass and glass ceramic materials as discussed by the authors, and bypass cement dust made up about 57 wt-...
Abstract: Bypass cement dust from the Rabigh plant in Saudi Arabia was examined for use in the preparation of technical coloured glass and glass ceramic materials. The bypass cement dust made up about 57 wt-...
TL;DR: In this article, the authors synthesize a number of semiconductor materials with X ≤ 0·10 using a solid state ceramic route to explore the possible applications as a capacitor or sensor materials.
Abstract: Undoped and donor doped SrSnO3 is used as a humidity sensor. The sensitivity increases with increasing donor substitution. Similarly acceptor doped SrSnO3 has high value of electrical conductivity. In the present investigation, compositions with X ≤ 0·10 were synthesised in the systems Sr1−xLaxSnO3 and SrSn1−xNixO3 by solid state ceramic route to explore the possible applications as a capacitor or sensor materials. All the compositions were found to form solid solutions and have orthorhombic crystal structure. Average grain size is in the range 0·7–1·2 μm. Densities of all the samples are >90% of the theoretical density. The electrical conduction behaviour of these systems was investigated by the measurement of Seebeck coefficient α and DC conductivity in the temperature range 300–1100 K. These materials exhibit p type semiconduction. Conduction occurs by diffusion of doubly positively charged oxygen vacancies. Electrical resistivity of all these three compositions is very high up to 300°C. These ...
TL;DR: In this article, the effect of nanoscaled hydroxyapatite (HA) filler particles on the mechanical properties of the high density polyethylene-hydroxyapatites (HDPE-HA) composite samples has been investigated.
Abstract: The effect of nanoscaled hydroxyapatite (HA) filler particles on the mechanical properties of the high density polyethylene–hydroxyapatite (HDPE–HA) composite samples has been investigated. Nanosized HA particles with an average size in the range of 40–50 nm were synthesised by mechanical milling method. The composite samples with various amounts of nanoscaled HA particles were produced by mixing the ceramic and high density polyethylene particles using a single screw extrusion system. The results of the mechanical testing on the composite samples showed an increase in the fracture strength and the young's modulus values with increasing volume fraction of HA content in the composite samples. At the same time, there were decreases in both the fracture strain and toughness values with increasing volume fraction of the ceramic filler particles. In addition the comparison of the results obtained in this study with the mechanical properties of the commercially available composite samples (HAPEX) shows ...
TL;DR: In the last 30 years, unexpected durability problems, such as the alkali silica reaction (ASR), delayed ettringite formation (DEF) and the thaumasite form of sulphate attack (TSA), have emerged as discussed by the authors.
Abstract: Plaster, cement and concrete have been used since antiquity, notably by the Romans. Portland cement was patented by Joseph Aspdin of Leeds in 1824. Since then it has been gradually refined to become the fundamental constituent of modern concrete, familiar to all of us as the major construction material of the past century. Contemporary constructions such as skyscrapers, concert halls, suspension bridges and huge dams testify to the successful use of Portland cement concrete. For routine constructions its compressive strength development and durability are sufficiently well understood for it to be used with confidence in many diverse situations and in locations with widely different climate conditions. Even in the last 30 years, however, unexpected durability problems, such as the alkali silica reaction (ASR), delayed ettringite formation (DEF) and the thaumasite form of sulphate attack (TSA), have emerged. To ensure that the civil engineer can take the necessary steps to avoid their occurrence has...
TL;DR: In this article, the effect of burning conditions on the properties of an artificial hydraulic lime mortar obtained by burning limestone and siliceous waste materials was investigated. But the results were limited to 3 h.
Abstract: The present study was carried out to produce an artificial hydraulic lime for repair and conservation of historic masonry. Lime mortar is preferred to cement based mortar for conservation work because it is more compatible with stone and ancient brickwork, as well as being a more sustainable material. The study focused on the effect of burning conditions on the properties of an artificial hydraulic lime mortar obtained by burning limestone and siliceous waste materials. The raw meals were prepared from five types of siliceous materials obtained as byproducts from industrial processes (pulverised fuel ash, glass cullet, silica sand, crushed rock and spent oil shale) with the amount of silica between 3 and 16%. The raw meal was burned in an electric furnace at 975°C for 3 h. The mortar was prepared by mixing hot slaked lime putty (water/lime ratio ∼1.6) and 'Gowrie' sand at a lime/sand ratio of 1 : 3 by weight. The limes and lime mortar were prepared and tested according to BS EN 459-2:2001. The inv...
TL;DR: In this paper, coal gangue has been used to produce porous ceramics, such as cordierite, anorthite lightweight brick and other lightweight aggregates, which can be used as a cement admixture.
Abstract: Disposal of coal mine waste (gangue) presents a serious environmental problem. In the present paper, applications of siliceous and kaolinitic gangues in ceramics, refractories and cementing materials are reviewed. Coal gangue series mullite, superfine β-SiC and Si3N4 powder have been prepared from siliceous gangue and carbon black, anthracite or bituminous coal. Using kaolinitic gangue with few impurities as raw materials, Al2O3–SiC and sialon–SiC composite powders, and sialon series powders including β-sialon, O-sialon and X phase have also been synthesised successfully. Kaolinitic gangue has been used to produce porous ceramics, cordierite, cordierite–mullite insulating brick, anorthite lightweight brick and other lightweight aggregates. Calcined coal gangue had high activity of volcanic ash and may be used as a cement admixture. Alkali activation is another effective method of improving the strength of coal gangue based alkaline cementitious materials.
TL;DR: In this paper, an extrusion-spark plasma sintering (SPS) was used to obtain a textured bulk ZnO ceramics with fine grains.
Abstract: Since texture was confirmed to improve the properties of ZnO ceramics in various applications, an extrusion–spark plasma sintering (SPS) process was utilised to obtain a textured bulk ZnO ceramics. Rod-like, anisotropic ZnO particles were utilised as the original powder. The particles were aligned in such a position where c axes of the particles were parallel to the extrusion direction after the extrusion process. By spark plasma sintering method, a textured, near full dense homogeneous bulk ZnO ceramics with fine grains was obtained, sintering at relatively low temperature and within short time. Since the orientation was only controlled in one particular direction, i.e. c axis direction, it was a fibre texture that was achieved in this bulk ZnO. The extrusion–SPS process was confirmed to be an effective technique to induce texture in bulk ZnO ceramics.