We have found that multi-color can be generated in soda-lime-glass containing Ag particles by femtosecond laser irradiation. Soda-lime-glass (bottle glass) was ion-exchanged in AgNO3/NaNO3 and heat-treated. With the femtosecond laser irradiation, the irradiated spot initially changed from original yellow to reddish, and then finally changed to blue.

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Five types of Ca₂SiOsub>4 solid solutions, doped with either P⁵⁺, Ge⁴⁺, Fe³⁺, Mg²⁺ or Ba²⁺, were prepared and examined by high-temperature X-ray diffractometry up to 1073K. The starting and finishing temperatures were determined for the α'_L-to-β martensitic transformation during cooling and the reverse (β-to-α'_L) transformation during heating. These four types of transformation temperatures for the preparations doped with either P⁵⁺ or Ge⁴⁺ steadily decreased with increasing substituted fraction. The effect of the substitution on the decrease for each transformation temperature was quantitatively evaluated by ΔT/x, where ΔT is the difference in the transformation temperatures between the solid solutions and pure Ca₂SiO₄, and x represents the fraction substituted for Si⁴⁺ or Ca²⁺ in the α'_L-phase structure. The evaluated value for the substitution of P5+ was more than three times that of Ge⁴⁺. The effect of the substituent ions mentioned above, together with Na⁺ and Sr²⁺, on the lowering of the starting temperature of the α'_L-to-β transformation was principally determined by the differences in the ionic radius between the interchanging cations.

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T1:It is noted that the blast-furnace slag cement is much subject to carbonate than OPC. The characteristic of hydraulic materials which effected on by hydration and carbonation can be known by investigating the silicate anion structures. The distribution of silicate anion structures of blast-furnace slag (BFS), converter slag and dephosphorized slag were analyzed by trimethylsilylation (TMS) method. The result of TMS analysis showed not shifting the silicate anion chain-lengthening in processing by hydration. However, the silicate anion was extended by hydration of converter slag, and it exhibited the action similar to BFS.

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This paper discusses the hydration products in Ca3Al2O6-2/3(CaSO4H2O)1-x-2/3(CaCrO4) x systems (x=0, 0.1, 0.25, 0.5, 0.75,0.9, 1) in the age of 91 days. The value of x shows the rations of chromate ion in this system. The XRD peak(CuKα·2θ=8∼11°)shifted toward to lower angle with increasing of the value x, in which the different type of AFM phase may be existed. It was elucidated that the different AFM phase was forward with SO42- or CrO42-.

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We synthesized Li₂O-CaO-Al₂O₃-SiO₂ glass. The very early hydration of samples was measured by isoperibolcalorimeter. The heat liberation of the sample containing Li₂O was higher than that of the sample not containing Li₂O. The heat liberation of each sample was decreased with increasing of Ca₃Al₂O₆ replacement ratio. The hydrated product was ettringite at very early stage.

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Effect of SO4 in cement mixing water on the initial property of cement was estimated for cement samples prepared by adding several kinds of sulfate. With the increase of SO4, fluidity of mortar prepared by adding PC (polycarboxylic acid-based water reducing agent) was improved at the lower SO4 concentration, whereas it was depressed at the higher SO4 concentration. It is considered that the former phenomenon is mainly due to regulation of C3A hydration and the latter is by hindrance to adsoption of PC on cement particles. As the result, SO4 concentration has optimum values concerning the fluidity of PC-added mortar.

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The chloride binding behavior of monosulfate hydrate (AFm) is investigated. The chloride binding curve of AFm can be represented by a Freundlich isotherm. The chloride binding of AFm mainly depends on the formation of Friedel' s salt by ion exchange between SO₄^2- and Cl^-. Theoretically, 1 mol of Friedel' s salt contains 2 mol of chloride ion. In this study, 1 mol of AFm bound 1.1 mol of chloride ion at a chloride concentration of 5mol/l. This is considered to be caused by the partial dissolution of AFm and the production of other hydrates such as ettringite.

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Changes in concentration of Pb ion in the high alkali solution with cement minerals or hydrates was measured by means of atomic adsorption method. Behavior of Pb ion in solution in the presence of cement minerals or hydrates at the high alkali condition was discussed. The concentration of Pb ion decreased with time in the calcium silicate system and it became lower than few ppm. On the other hand in the case of calcium aluminate system, the concentration didn' t decrease so much and it was about 20-40ppm.

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This paper discusses about influence of various types of superplasticizers on the hydration of cement and pore structure of hardened cement. Hardened cement with LS and β-NS had much pore of more than 0.1 μm compared with the case of P34 and S34 which had much pore of less than 0.1 μm. Cluster or flocculation of cement particles in fresh cement paste with superplasticizers was influence on the pore size distribution of hardened cement paste.

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The mechanism of the reduction of drying shrinkage by a cement dispersant or a superplasticizer with multifunction (TNT13) that is the cement dispersing and the dry shrinkage reduction was investigated. A commercial superplasticizer (SP) and an organic shrinkage reducer are evaluated as references. TNT13 can reduce the drying shrinkage as much as 12% keeping the flow of mortar constant compared to SP. A positive linear relationship between the surface tension of the pore solutions extracted from hardened mortar and the rate of drying shrinkage indicates that TNT13 reduces drying shrinkage by reducing the surface tension of pore solution.

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In order to discuss the rheological properties of suspension using with parameters described numerically, many parameters were proposed from image analysis of suspension. Suspensions were prepared with mono-dispersed silica powder, whose suspension had solid contents of 42 to 56 volume% under the pH of 2 to 10. The suspensions were freeze-dried and solidified with resin. The polished cross sections were observed and analyzed with a program of image analysis (Media Cybernetics Co.Ltd). Parameters of distribution and average flocculated number, distribution and average volume of effective flocculated particles, the volume of entrapped water in flocculated particles, etc, were discussed.

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In order to discuss the relationship between structural parameters and rheological properties for concentrated suspension, a parameter of average effective mass of flocculated particles in the suspension was proposed. The suspension of mono-dispersed silica powder were prepared with the solid contents of 42 to 56 volume % under the pH of 2 to 10 which were controlled by HCl or NaOH solution. The structure of suspension was analyzed by image analysis using with SEM images. The viscosity for suspension was not able to be described only with solid ratios, when the state of flocculation varied. However, the average effective mass of particles was very available for the description of relationship between structure and rheological properties of suspension.

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It is important to clarify adsorption and dispersion mechanisms of comb-type polymer. This paper discusses the relations between molecular structure and adsorption of comb-type polymer. Comb-type polymers having different graft chain length and the ratio of functional groups (-SO3-/-COO-) were used. Comb-type polymer having larger ratio of functional groups has lower value of Kw when K2CO3, K2SO4 added. It seems that the adsorption of comb-type polymer depends on the molecular structure.

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As the dairyfarming and stock-raising farms in Hokkaido is becoming large-scale, a severe problem has appeared with a large amount of sewage mudding the paddock and polluting the water. In order to clean the paddock and treat the sewage addequately, new paving material suitable for paddocks is required . On the other side , the lime cake wasted from sugar-plant is forced to be utnized by environmental reasons. In this study , a new paving material we have developed using lime cake is discussed.

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This study was aimed for the influence of quick setting agents for calcium silicate hydrates. Further, the morphology and reaction mechanism were studied on the autoclaved calcium silicate hydrates added quick setting agents in low water powder ratio were.

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This paper proposes the new recycling system of construction materials by using of carbonation reaction and calcination. Carbonated high belite cement can obtain high strength and can be used as high durable construction materials. Belite rich cement was easily produced by calcinating the carbonated high belite cement at low temperature (750∼1300°C).

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The hydrothermal solidification of the sludge from water purification plant was investigated. The sludge was mixed with 0-20 mass% of Ca(OH)₂. The mixtures were formed by uniaxial pressing and hydrothermally treated under saturated steam pressure at 220°C for 10 h. The flexural strength of the specimens increased with amount of added Ca(OH)₂ to 5 mass% and reached the maximum value of 13.0MPa. The nanostructure formed through the hydrothermal treatment influenced on the strength development. The Al/Si atomic ratio of the compounds which constituted the nanostructure was in the rage of 1.0 to 1.5.

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MWCNTs were coated with SiC using simple method that had been established for diamond particles in our laboratory. SiC-coated MWCNTs were characterized using XRD, AES, SEM, and TEM. Oxidation properties were evaluated by TG-DTA. Starting temperature of oxidation and oxidation durability were improved remarkably.

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Alumina films with various thicknesses were synthesized using a chemical vapor deposition technique operating under atmospheric pressure. The films were deposited on silicon and stainless steel substrates. The failure modes associated with the test occurred at different critical loads and appear to be distinct. In the case of film deposited on silicon, a complete delamination causing tearing of the film from the substrate was observed.

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In this study, hydrogen storage mechanism of a-CNx:H have been investigated by combination of electron spin resonance (ESR), FT-IR and Raman spectroscopy. The result of ESR revealed that the density of unpaired electron spin decreased after hydrogen storage. Although the IR absorbance of CH3 and CH2 stretching modes increased after hydrogen storage, Raman scattering spectrum was unchanged. These results suggest that the dangling bonds of a-CNx:H are consumed by hydrogen absorption.

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Yttria stabilized zirconia (YSZ) films were prepared by CVD at a rate of 100 μm h^-1. The YSZ films had a columnar structure consisting of polycrystalline grains with 100 to 400 nm in size. Many nano pores 100 to 200 nm in diameter were observed at the grain boundary. The thermal conductivity of CVD YSZ films were 0.8 to 1.4Wm^-1K^-1, being smaller than that of sintering.

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Rciprocal space maps of CeO2/YSZ/Si (001) grown by PLD method were obtained at high temperature by adding a heater to the sample stage. CeO2 and YSZ thin films were epitaxally grown. By measuring lattice constats at high temperature it is conducted that a-axes of CeO2 and YSZ thin films parallel to the substrate surface showed smaller thermal coefficients than bulk reference and a-axes perpendicular to the surface showed larger thermal coefficients. When SrTiO3 thin film was dedeposited on CeO2 layer, lattice change of CeO2 with increasing temperature differed from that before depositing the top layer.

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We have succeeded in preparing YSZ films at high deposition rate of 660μm/h using newly developed laser MOCVD. In this study, effects of incident laser power (P_L) and substrate pre-heating temperature (T_pre) on deposition rates and microstructures were investigated. When P_L=200 W, YSZ films with a columnar structure were prepared at P_L from no pre-heating to 750°C. The deposition rate at P_L=200 W and P_L=550°C was 450μm/h and the YSZ film had a highly (200) oriented columnar structure.

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YSZ thin films were prepared by laser CVD. The deposition rates were significantly increased to 660μm/h by the assistance of laser irradiation. Particular light emission was observed during the laser CVD process. Negative and positive space charges were identified in the reaction zone, where the charges mainly consisted of ions. The emission spectra were continuous, and sharper than the Planck distribution. Intermediate clusters could be heated at around 4200K in the reaction zone.

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Zirconia-based ceramics such as yttria-stabilized zirconia is currently used for thermal barrier coatings (TBCs) for gas turbine component. TBCs produced by electron beam physical vapor deposition (EB-PVD) show a columnar structure which offers superior tolerance against stresses and thermoshock. There is potential for lowering thermal conductivity of TBCs produced by EB-PVD by controlling their micro- and nano-structure including nano-pores and nano-gaps. In this study, the effects of processing parameters of EB-PVD on the micro- and nano-structure of zirconia-based ceramics coatings were investigated.

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We investigated preparation of perovsikte oxide using electron beam physical vapor deposition (EB-PVD). The evaporation source was La0.8Sr0.2MnO3 and the substrate was disk of 8mol% Y2O3 stabilized ZrO2. The XRD pattern of deposited film by EB-PVD was indexed by cubic cell. Composition of the deposited film was almost same as that of evaporation source. The deposited film had a columnar microstructure that was characteristic of EB-PVD.

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This study was carried out to clarify systematically the crystal orientation dependence of cleavage surface energy, γs of SrTi03 single crystal by molecular dynamics calculation. It was found that the lowest cleavage surface energy was the lowest in (001), which was non-polar plane, and the highest in (011), which was polar plane, orientations. From these findings, it was concluded that crystal orientation dependence of γs was strongly correlated with surface charge density.

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Deformation of Ce-TZP at high temperature was studied. The stress exponents n=1 were obtained for grain sizes from 1.5 to 4.1 μm, showing the deformation is not superplastic but is diffusional flow. Because the diffusion of anion is much faster than that of cation, the latter is rate controlling. Apparent grain size dependence of deformation (p∼2) suggests that the deformation appears to be controlled by cation lattice diffusion. However, calculated diffusion coefficients were found to be in agreement with the reported values for cation grain boundary diffusion. The apparent disagreement is explained probably by the existence of sub-boundaries in the grains.

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Atomic structures and high-temperature mechanical properties of [0001] symmetric tilt grain boundaries in alumina (Al2O3) bicrystals were studied by high-resolution electron microscopy (HRTEM) and compressive creep tests. Al2O3 bicrystals were obtained by a diffusion-bonding technique, and it was found from HRTEM observations that their grain boundaries showed characteristic core structures, depending on their misorientations and grain-boundary planes. From creep tests for Al2O3 bicrystals, grain-boundary sliding rates were also found to depend on grain boundary characters, which is likely related to the core structures at grain boundaries.

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Compressive residual stress improves the apparent strength of ceramic materials. In this study, a multilayered composite, which has surface nanocomposite layers and a monolithic inner layer, was fabricated and evaluated. From the Vickers indentation test, it was proved that crack propagation is strongly depressed by the compressive stress and nano particle.

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lnstrumented indentation tests were carried out on alumina and metal specimens for discussing the influence of the machine compliance to the calculated hardness. It was anticipated that the obtained loading curve could be divided into three contents, deformation of the specimen, deformation of the testing apparatus and initial error at the contact. However the simple analysis could not supply the same elastic constant of the apparatus from loading and from unloading. Further analysis was required for obtaining the hardness value as a material constant.

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Stereo matching method was applied to the reconstruction of the three-dimensional fracture surfaces in impact-fractured ceramics and fatigue-fractured metals. The fractal dimension and the surface roughness were then estimated on these fracture surfaces. The global fractal dimension of the fracture surfaces estimated by the box-counting method was in the range from about 2.10 to 2.22 in both ceramics and metals. In ceramics, the fractal dimension of the three-dimensional fracture surface was correlated with the fractal dimension of the indentation crack estimated in the similar scale length range. It was found that there was a difference in the local variation of the fracture surface roughness between these materials. Further, the local variation in the fractal dimension was also experimentally discussed.

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Thin film heaters made of lanthanum chromium oxide (LaCrO₃) have been fabricated with RF magnetron sputtering method. Thin film of Sr doped LaCrO₃ oriented in the direction of (220) or (004) compared with Ca doped that. In general, the resistance of the films decreases at higher concentrations of Ca or Sr. In the same Ca or Sr mixing ratio, the resistance of Ca doped LaCrO₃ heater was smaller than Sr doped that. However, the electric stability of the films became poor with increasing amount of Ca or Sr. Thin film was uniformly heated. EPMA results of these thin films before and after heating showed no difference of composition, while the evaporation of chromium atoms from thin films under cathode Pt electrodes was suggested. When the thin film electric heater was heated to high temperature, it was destroyed by the inner stress due to the thermal expansion of the substrate. The maximum heating temperature was over 1300°C by using a thick substrate.

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Alumina rich spinel solid solution were synthesized from the reaction with normal spinel (Al2O3:MgO=1:1) and alumina. For starting material, single crystal and polycrystalline of normal spinel and also of alumina were prepared. Each powdered material was mixed and calcined 1450°C for 1 h, then kept at 1750°C for several hours for reaction. Samples were examined by X-ray diffraction. The lattice parameter of spinel changed to smaller value showed that the alumina rich solid solution was made by these procedure.

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The ltacolumite (Konnyaku-Ishi) which exists naturally has a three-dimensional crack between the grain boundary similar to the jigsaw puzzle, and makes plastic deformation possible. In this research, we used the difference in thermal expansion coefficient of two ceramics, made crack similar to ltacolumite. Potassium zirconium phosphate (KZP), which has low thermal expansion, and potassium aluminum silicate (Leucite) which has high thermal expansion mixed at a predetermined rate and sintered after one axis pressurization forming. Particle diameter of KZP and Leucite were 100∼250 and 250∼500 μm. The crack could be made between the grain boundaries.

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Ceramics have a disadvantage of brittleness. In order to improve it, ceramic composites with plastic resin have attracted attention. Mechanical properties of porous alumina and porous alumina impregnated with epoxy resin were investigated, and the condition of impregnated resin was observed by scanning electron microscopy. Mechanical properties such as effective fracture energy of the composite were improved by impregnating porous alumina with resin.

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The Control of thermal expansion of material was examined by co-sintering of ZrW₂O₈ with negative thermal expansion and ZrO₂, SnO₂, TiO₂ and Y₂O₃. It was revealed that control of thermal expansion of SnO₂ and ZrO₂ was possible by hybridization with ZrW₂O₈, whereas it was not for TiO₂ nor Y₂O₃.

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Hydro corrosion resistance of Ln2Si2O7(Ln=Nd, Er, Lu), mullite (Al6Si2O13), apatite phase (CaYb4Si3O13) and Al2O3 was investigated at 1500°C. In Ln2Si2O7 phases, Ln=Nd and Er samples were completely dissolved by aggressive water vapor at 1500°C. apatite phase was decomposed during corrosion test. Lu2Si2O7 and mullite showed excellent water vapor corrosion protection.

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Dense and fine grained yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) were fabricated by a two-step sintering technique. The Y-TZP powder compact was heated up to a temperature (T1;1300°C, 1350°C, and 1400°C) where the sintering set in the intermediate stage, and then was cooled down and held for 20 h at a temperature (T2) which was 10°C to 150°C(ΔT:T2-T1) lower than T1. The relative densities were kept being around 96% at T1= 1300°C over the ΔT range of 0-40°C, whereas they were around 98% over the ΔT range of 0-50°C at 1350°C and over the range of 0-100°C at 1400°C. The average grain sizes were as low as 0.25-0.3 μm and the grain growth was inhibited compared to the case of single-step sintering, i.e., the heating up to the desired temperature (T1), holding for 20 h, and then cooling down to room temperature.

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It is well known that the mechanical properties of the yttria stabilized zirconia (Y-TZP) is degraded in hydrothermal water. In this study, re-sintering of Y-TZP disintegrated by hydrothermal treatment of Y-TZP ceramics in pure and acid water was investigated. All monoclinic phase brought by hydrothermal treatment was restored to tetragonal phase by calcination and sintering. Therefore the recovered powder has a possibility for re-sintering of Y-TZP. However the conditions of ball-milling and calcinations are not optimized enough.

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An alumina-Tungsten Functionally Gradient Material (FGM) was obtained by Centrifugal Molding Technique (CMT). It is found that the mixture of two kinds of sub-micro powers is unsuitable to fabricate the FGM cylinder by CMT, though there is large difference in density between two constitutes. The use of mixture of metal particles with different size is particularly useful to get the continuous graduation of the FGM cylinder. Adjusting the mixture ratio of metals with different particle sizes can control the graduations along the radial direction. The hoop residual stresses distributed from tensile on the inner surface to compressive on the outer surface due to the gradual material properties of the alumina-tungsten FGM cylinder.

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Graded porous ceramics was fabricated by centrifugal casting using alumina-PMMA slurry. The slurry was prepared dispersing the powders ultrasonically in deionized water with dispersant agent. The concentration of the dispersant affected the pore distribution. The sphere pores with about 10 μm diameter, which corresponded to PMMA particle size, were observed and increasing toward the inner surface gradually. Air permeability increased in proportion to the porosity and fracture strength was decreased with increasing porosity.

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The ceramic composite materials dispersed with metal particles demonstrates the bridging effect during the fracture. In order to evaluate the effect of the alumina reinforced with small or large stainless-steel (SUS316L) particles, crack opening displacement (COD) was measured in situ in the scanning electron microscope (SEM). The COD profile of the composite with a small stainless-steel particle did not exhibit noticeable crack-face interaction. For the composite with a large stainless-steel particle, on the other hand, the shielding effect was recognized in the range from a crack tip to 600μm.

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Alumina/nickel composites were fabricated by spark plasma sintering (SPS), and the thermo-mechanical properties were evaluated. Furthermore, the residual thermal stresses generated in multilayered alumina/nickel FGM plates during sintering process were predicted. Then the optimum compositional gradient was designed and the crack-less alumina/nickel FGM disks were fabricated.

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The effect of solidification and sintering on the microstructure of Al2O3-GdAlO3 eutectic ceramics. A mixture of Al2O3-GdAlO3 was melted and rapid-quenched, resulting in an amorphous film. It was heated to be crystallized, then ground and sintered both by normal sintering and Spark Plasma Sintering (SPS) . Sintered body done by a normal sintering had a coarse structure due to the crystal growth. Only a combination of rapid-quenching and SPS resulted in a fine eutectic structure.

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Alumina ceramics were densified by pulse electric current sintering (PECS) using transition alumina powders prepared from polyhydroxoaluminum (PHA) gels at sintering temperatures of 1250∼1550°C for holding time of 5 min under uniaxial pressure of 30 or 40 MPa. PECS process enhanced densification in the sintering of transition alumina powders prepared from PHA gels, resulting in specimens with a relative density of more than 99%. The use of the sample powders ground by the high purity pot (Al2O3: 99.9%) made the sintering temperatures shift to lower temperatures, as compared with the sample powders ground by the low purity pot (Al2O3 : 93%). The bending strength of sintered compacts fired at 1300°C reached a value as high as about 860 MPa using the sample powders calcined at 900°C.

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Electrophoretic deposition of single crystalline α-alumina particles dispersed in aqueous media was performed in a strong magnetic field of 10 T. The α-alumina particles in stable suspension were aligned due to their anisotropic diamagnetic susceptibility and then deposited on a cathodic substrate. Orientation of α-alumina crystallites was dependent on the angle between the directions of a magnetic field and an electrophoresis of the particles.

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Electrophoretic deposition (EPD) is an effective forming technique to fabricate the dense and porous ceramics. In this study, various ceramics composites were fabricated by EPD method. Green bodies prepared by EPD method were fabricated by pressureless sintering at 1100∼1300°C. The microstructures were observed by SEM. These results suggested that ceramics composite can be fabricated by controlling pH of suspension and current/voltage.

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First, fine alumina powder was compacted and calcined at 1000°C for 1h. Then, YAG solution was impregnated into the calcined compact. After that, these compacts were dried. This process was repeated several times. Finally, they were hot-pressed between 1400 and 1500°C in Ar flow for 1h under a pressure of 30MPa. Concentration of YAG after 5 times impregnation and then hot-pressed at 1400°C was about 10vol.%. The bending strength was about 680MPa.

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The "transparent" ceramics are interesting because they have the potentiality of many applications. The transparent ceramics are generally got as amorphous based upon glass components, silicates, germinates, borates etc. Taking the super rapid quenching method, amorphous materials might be got in composites containing no glass component. But the amorphous fabricated by super rapid quenching may limit the shape to film. In this study, we have fabricated successfully amorphous materials from HfO₂-Al₂O₃-GdAlO₃ composites without glass components. Furthermore, we have got nano-structured bulk ceramics by annealing the amorphous ceramics.

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