Although ceramic materials are considered inherently brittle, superplastic behavior has been observed in many fine-grained ceramic materials with large elongation to failure at high temperatures. This
paper reviews the major features of superplasticity, the deformation characteristics and mechanism of yttria-stabilized tetragonal zirconia polycrystals, a typical superplastic ceramic, and the effects of dynamic
grain growth, glassy phase and concurrent cavitation on the deformation behavior of Y-TZP. The superplastic behavior of other ceramic materials, including Al₂O₃ Al₂O₃-Y₂O₃ stabilized tetragonal
zirconia composites, covalent ceramic materials, nanostructured ceramics, and glass-ceramics are also summarized.

Direct Coagulation Casting (DCC) is a near net shape forming technique for complex shaped ceramic green bodies with high quality and
homogeneity. Double layer stabilized concentrated ceramic suspensions are solidified by shifting the suspensions pH towards the isoelectric
point using the in situ enzyme-catalyzed reaction, which minimizes the repulsive forces between the suspended particles. The remaining,
attractive Van der Waals forces form a stiff, wet green body. One of the most important process in DCC is preparing the ceramic
suspension with high solids loading (>55vol% ) and low viscosity, the other key technique is controlling the enzyme-catalyzed reaction .

TiO₂ oxygen sensors are widely used. The oxygen-sensing mechanism and ceramic, thick filmand thin film techniques used for manufacturing the sensors were presented. The wads of improvingthe properties of TiO₂ oxygen sensors were also discussed.

The mechanism of microwave interaction with substance was analyzed by means of Maxwell electromagnetic theory. The results showed that the microwave absorption
of substance was caused by the conductive loss and dielectric relaxation loss of substance, at high temperatures the conductive loss will be main loss. Heating
with 2.45GHz microwave, the substance conductivity must be lower than 1Ω^-1cm^-1. With the conductive data. The microwave heating charaeteristic of some inorganic
nonmetallic materials were evaluated. The temperature distribution within a sample was described with some hypothesis when microwave heating. The behavior of
nonhomogeneous solid under microwave irradiation was simply evaluated and predicted.

A high temperature in situ observation method was newly developed to study the buoyancydriven convection in KNbO₃ melt. A thin loop-like Pt wire heater (about 2.5mm in diameter)was employed to heat and suspend the KNbO₃ melts. A thin plane film of the sample melt wasformed. The temperature and fluid velocity profiles in the melt were measured experimentally.The quantitative analysis for the velocity of the fluid flow was also made theoretically.

Ti and Fe co-doped LiNbO₃ crystals were grown from the melt by Czochralski method. The influence of different doping concentration on photorefractive
effect was studied, the optical transmission spectra before and after reduction treatment were measured too. It was confirmed by ESR method that Ti
ion exists in untreated Ti: Fe: LiNbO₃ crystals in the form of Ti⁴⁺. It was supposed that the Fe²⁺ concentrations increase in untreated Ti: Fe:
LiNbO₃ crystal due to charge compensation effect. Without reduction treatment, the concentration of Fe²⁺ in crystals can be controlled by Ti dopping.The diffraction efficiency , which can be high up to over 90.00%, was also
measured by using two-wave coupling technique. Ti: Fe: LiNbO₃ crystal is a good new photorefractive material.

Large size PbWO₄ single crystals were grown from PbO and WO₃ powders of 99.99% purityby modified Bridgmajn method (MBM). The transmittance and steady-state X-ray excited emissionspctra of the grown crystals were studied. The results show good homogeneity in transmittanceand luminescence along the longitudinal direction of the crystals, which can be mainly attributedto the effective inhibition of vaporization of the constituents by the sealing of crucibles in MBM.

The method of differential thermal analysis (DTA) was used to investigate the effect of TiO₂ on the crystallization of CaO-Al₂O₃-SiO₂ system glass.
When TiO₂ is added to the CaO-Al₂O₃-SiO₂ system glass, the glass network becomes more loose, that leads to the viscosity of glass, transition temperature
T_g and crystallization peak temperature T_p decreasing. That the glass is difficult or easy to crystallize does not mean that the crystallization
peak temperature T_p is high or low. Whether the CaO-Al₂O₃-SiO₂ system glass contains TiO₂ or not, the glass mainly begins to crystallize from the surface.
When TiO₂ is used as a nucleation agent, its effect on promoting crystallization is not obvious. After heat-treatment at the nucleation temperature for a long time,
CaO-Al₂O₃-SiO₂ system glass containing TiO₂ still begins to crystallize from the surface, and the more TiO₂ the glass contains, the more obvious the surface crystallization is.

Mica glass-ceramic/Y-TZP composites were prepared and characterized. The transformation fraction of t-ZrO₂ decreased with the content of Y-TZP, determined by X-ray
diffraction analysis (XRD). The transformation width increased with increasing the content of Y-TZP, confirmed by Raman micro-area probe method. The mechanical properties
of mica glass-ceramic were significantly improved with the incorporation of Y-TZP. The flexural strength and fracture toughness of the glass ceramic doped with 40vol% ZrO₂
were as high as 446MPa and 4.8MPa·m^1/2, respectively. The stress-induced t-m transformation of zirconia dominantly contributed to the improvement of the fracture
toughness; however, crack deflection also played an additive role in the improvement of the fracture toughness of the composites with a relatively higher content of Y-TZP.

The microstructures of two α-Sialon/SiC_(w) composites sintered in N₂ and N₂+CO atmosphere respectively, were studied by using TEM, HREM and EDS.
TEM observations revealed quite different interface stuctures in-between those two composites. A strong interfacial bond between α-Sialon matrix and
SiC whisker was observed in the composite sintered in N₂, while for the composite prepared in N₂+CO, a thick layer of glass was found to be formed at the matrix/whisker
interface. The glass was produced by the reaction between CO gas and the SiC whisker surface. Albeit different interface structures, both composites decreased mechanical
properties because the cracks progressed directly across the whisker rather than circumferentially. Possible processes were proposed in order to improve the mechanical
properties of SiC whisker reinforced α-Sialon composites by tailoring the interface microstructures of the composite.

氧化铝; 细晶粒; 氧化镁; 作用机理

The series deficient compounds La_2/3TiO_3-λ(λ=0.000-0.046) powders were hydrothermallysynthesised from double hydrous oxides La₂O₃·3TiO₂·nH2O, and characterized by XRD, TEMand other technologies. The cell volumes of the products would change to large with the increasingof deficient oxidation, and the crystal symmetry transforms from orthorhombic to tetragonal at λ=0.020. The payticle-sizes of these powders were about 0.1~0.3μm with a mode of particle-sizedistribution, and increased with the increasing of deficient oxidation.

The mechanism for SHS AIN was investigated A novel quenching technique was used to retainthe high-temperature structure formed in the sample during combustion process. Based on themicrostructure observation and thermodynamic analysis, two-step mechanism for SHS AlN i.e.,vaporization of Al and subsequent reaction with N₂ was proposed.

The photolumenescence spectra of modulation doing GaAs/Al_0.27Ga_0.73As multiquantum well structure were measured. There are a strong luminescence peak
and several low energy weak peaks in the luminescence spectra. The strong one arises from transition of electron at ground state in well to heavy hole and these low energy
weak peaks may be attributed to transition of electron at DX centers in Al_0.27Ga_0.73As to Si_As atoms. On this view, we can come to the conclusion
that the DX centers in Si-doped AlGaAs appear as four levels and their activation energies are about 0.35eV, 0.37eV, 0.39eV and 0.41eV, respectively.

This paper studied the preparation of CaS powders by sulfurizing CaCO₃ in different atmosphere such as S+N₂, S+air, H₂S+H₂, H₂S, S+H₂S and S+H₂S+H₂ with different
reactive methods. The formation of impurity phases such as CaSO₄ and CaO depends strongly on the sulfurizing atmospheres. The amount of F^+ vacancies and the influence of F⁺
vacancies on the blue luminescence of CaS:TmF₃ phosphor were studied by photoluminescent (PL) and photoluminescent excitation spectra (PLE). It is concluded that CaS powders
containing large amount of F⁺ vacancies are not suitable for preparation of efficient CaS:TmF₃ phosphor because of the energy transfer from host and Tm³⁺ luminescent centers to the F⁺
vacancies. The qualified CaS powder for CaS:TmF₃ phosphor was prepared by sulfurizing CaCO₃ in S+H₂S atmosphere.

The complex dielectric response of tungsten bronze Sr_1-xBa_xNb₂O₆ [SBN(1--x)/x, x=0.40, 0.50 and 0.60] relaxor ferroelectric ceramics was
carefully studied as a function of temperature between --180℃ and 450℃. Three distinct relaxation features were observed in all the compositions.
The thermal hysteresis of dielectric maximum was considered to be associated with “lock in” of the incommensurate phase. It was confirmed by investigation of
the Curie-Weisis behavior at a higher temperature range. These results were also discussed in terms of the polarization fluctuation of polar microregions briefly.

The crystallization behavior and structural transformation of Sol-Gel TiO₂/SiO₂ thin films varing with composition, temperature, time were studied. With the increase of TiO₂ concentration,
the temperature of TiO₂ crystallization and the rate of structural transformation from anatase to rutile were decreased. The temperature of SiO₂ crystallization and the grain size of anatase
crystallites decreased and increased with the increase of TiO₂ concentration respectively, and the later one increased with annealing temperature as will. The grain size of TiO₂ crystallites was varied linearly
with the root square of annealing time. The difference of the rate of structural transformation from anatase to rutile depends on mainly the stress in the films.

The silica particles were examined by means of transmission electro-microscope (TEM) duringthe course of growing. It was observed that at the initial stage, the silica particles consist of floe,with the density being low, while after the initial stage, the silica particles became condenser,the growing elements are small condensed species. On the bases of the TEM exarnination andexperimental results made early, a mechanism of formation of monodisperse silica particles wasput forward and a detail discussion was made on the mechanism.

Co/Pt multilayer films were prepared by DC magnetron sputtering. Detailed vacuum annealing was carried out on them. The results show that moderate annealing at lower temperature can imcrease
the coercivity in Co/Pt multilayer films while not affect the shape of Kerr hysterisis loops. Annealing at or above 300℃ will cause the drastic decrease in coercivity, perpendicular magnetic anisotropy and
Kerr rotation in Co/Pt multilayer films. The improvement of crystal structure and the release of stresses in films, the growth of grains, the reduction of effective Co layer thickness caused by atom diffusion
between layers and further the decrease in Curie temperature are considered to be responsible for the changes in magnetic and magneto-optical properties for Co/Pt multilayer films during lower, middle and
higher temperature annealing, respectively.

A-C Impedance spectroscopy and steady-state D-C polarization have been investigated tocompare oxygen diffusion on Pt, An, Ag, Ag-Pd four pasted electrodes and electrochemical reactionrate from 200℃ to 600℃. Electrode interface impedance has been calculated in the temperaturerange of 350-600℃. Experiments confirm the relationship of the exchange current density I_o asa function of oxygen partial pressure P^0.67±0.1_O2

A new liquid source using water as a solvent was studied to prepare Ba_0.5Sr_0.5TiO₃ (BST) thin films by Sol-Gel
technique. DTA/TGA methods were employed to analyze this water-based BST liquid source gel. XRD results show that the film exhibits a completely
pure perovskite phase. SEM photographs show that the thickness of the films is homogeneous, and the grain size of the thin films annealed at 650℃
for 20min is about 200nm. It is found that the thickness of the film plays an important role in the dielectric properties of the BST films. The BST films
of one layer with the thickness of 1250A have better dielectric properties than those of the multilayers. The dielectric constant and dielectric loss for single
layer BST films are 330 and 0.043 at 1kHz, respectively.

A technique of burn-out for low temperature cofired AlN multilayer substrates was introduced,which consist of high thermal conductivity AlN ceramics and metal W. The effect of the evolutionof carbon during burn-out on AlN sintering characteristics and microstructure was studied. Theresults showed that two-step burn-out process may solve the contradiction between W oxidationand residual carbon.

Zirconia fibers, 1~2μm in diameter and 1~5cm in length, were synthesized by spray pyrolysisof airconyl acetate solutions. The effects of precursor solution concentration, surface tension,viscosity on morphology of the resultant fibers were studied. Solid and hollow fibers were obtainedby controlling the operating parameters.

A plane finite element model was established for two-phase ceramics. The residual stress distribution in the model was analyzed, and the variation regularity of
internal stress along with the second phase particle’s volumetric proporation was given. The effect to residual stress was also discussed, which is caused by the
variation of relation between the thermal expansion coefficients of the matrices and the second phase particles, the difference between interface stress of theoretical
value and calculated one was discussed, and some viewpoints of toughness enhanced mechanism for this composite material were concluded.

Nanocrystalline Ni-Zn ferrite was synthesized by mechanochemical reaction from α-Fe₂O₃,ZnO and NiO powders through high energy ball milling. The synthesized samples were characterized by XRD, TEM and Mossbauer spectroscopy. The results showed that the as-millednanocrystalline size was about 5~20 um, which exhibited superparamagnetism, and the size ofthe nanocrystallite after annealed at 800℃ for 2h increased to about 50 um, which exhibitedferrimagnetism

²⁹Si, ¹¹B, ²³Na MAS NMR were employed to study the structure change of the Na₂O-B₂O₃-SiO₂ glass in the process of
thermal treatment of phase separation. The results show that oxygen atoms are deleted among the [SiO₄] structure units and the aggregation degree of Si
increases in the process of phase separation. In the meantime, the structure of boron atoms in silicon-rich phase is transformed gradually from [BO₃] to
[BO₄] and [BO₄] units enter into sodium-boron rich phase. The difference between the compositions of the two phases gradually increases. The phase separation
is the result of diffusion and mass transfer. Moreover, the glass has a more rapid structure adjustment rate at a higher temperature of thermal treatment,
thus can get to the equilibrium state faster.

The silicon nitride ceramic piston crown is a critical component for the cooling-free diesel engine. The piston crown material used is GPS-RBSN with rare-earth oxide additives,
sintered in the range of 1800～1960℃, under nitrogen pressure of 0.1～6 MPa, and its bend strength being 750 MPa, K_IC 7.2 MPa·m^1/2, weibull Modulus 12.3.
Piston crowns made from this material were assembled in 6105 cooling-free diesel engines, the diesel engine constructed was
rig-tested for more than 700 hours. The engine was installed in an EQ2060 truck and road-tested for more than 1900km in desert and no trouble found.

The joining of silicon nitride ceramics using oxynitride glass as the interlayer material wasstudied in this paper. The results showed that the bonding strength of joined silicon nitrideceramics was up to 57% of that of the silicon nitride ceramic matrix. The joint zone had the samemicrostructure as the ceramic matrix , but smaller grain size. The similarity in the microstructuretakes a great role in the increase of bonding strength.

Diamond growth phase diagrams were calculated under different activation temperaturesbased on non-equilibrium thermodynamic coupling model. The diamond growth regions are enlarged with the increase of activation temperature. As to different substrate temperatures, thediamond growth regions exhibit different tendency with activation temperature rising.

Fluorine gas was produced with the electrolysis of the molten salt KF·2HF, then graphite fluoride was prepared
through the reaction between graphite powder and fluorine gas at 500℃. The real density of the graphite fluoride was 2.53g/cm^3, its electrical resistivity 3.1×10³Ω·cm
and its colour greyish white. The graphite fluoride synthesized had a absorption peak of infrared reflection spectra on F--C covalent bond at approximation wavenumber
1219cm^-1 and 1350cm^-1. By testing friction factor for the graphite fluoride, graphite powder and molybdenum disulphide, the experimental results showed that the friction
factor of the graphite fluoride was the smollest. Furthermore, technological conditions and special properties of the graphite fluoride were dissussed.

The optical properties, decomposition process and recording properties of AgO_x films wereinvestigated. The results showed that AgO_x films prepared by using dc reactive sputtering underthe condition of Ar pressure of 0.67Pa ajnd O₂ pressure of 2.OPa were amorphous and completelydecomposed into Ag at 400℃. The static writing of AgO_x films was successfully accomplished.AgO_x may be promising to become a new kind of CD-R recording media.

Spindle-shaped α-FeOOH was prepared from FeSO₄ and different alkalis or mired alhalisrespectively. The morphology of a^-FeOOH was observed with TEM. The result shows that its axisratio related to [OH^-], the higher concentration of [OH^-], the longer axis ratio; α-FeOOH waslike the ellipsoid with caxbonic concentration increasing, because the short tals became Ionger andxis ratio smaller. The essential cause of formating spindle-shaped α-FeOOH particles was thecoagulation of CO ion bond.