Joining of ceramics is one of the most difficult techniques which should be developed for the wider application of structural ceramics. The good chemical compatibility between silicon nitride alld oxyllitride glass Provides the possibility to imcrease the effectiveness and reliability of silicon nitride joints. The propertics of oxyllitri(le glass, joining nlecllanisln and effects on bonding strength were reviewsed in this paper.

A new idea was proposed for solving the problems caused by different hydrolysis rate of alkoxides in Sol-Gel processes. The new idea is that the highest-hydrolysis-rate
alkoxide is supposed to be hydrolysized slowly and homogeneously at first under a controllable condition, and meanwhile, its hydrolysis intermediates polymerize with
lower-hydrolysis-rate alkoxides. Based on this new idea, a Sol-Gel process with lower cost and a simple procedure was developed for synthesizing BAS glass-ceramics.
XRD, DTA and Laser Raman Spectrum were used to detect the molecular structures and crystallization behaviors of a gel and a gel-derived glass. The as-prepared gel is
amorphous with (Si, Al)--O network structures. The temperature of maximum-nucleation-rate of the amorphous is about 938℃, and the temperature of maximum-crystal-growth
is about 1164℃.

The rutile single crystals were groawn by Verneuil method with the raw material of the ultrafine TiO₂ powder. The crystals were oxidized and annealed at different temperature for different time.The optical absorption of the crystals was investigated by means of UV-VIS, FT-IR. Moreover,the influence of the Powder characters and the growth atmosphere on the crystal groawth was also studied.

The SPS (Spark Plasma Sintering) process is a new materials synthesis processing technology recently developed by Sumitomo Coal Mining Co.Ltd.,
Japan. Some oxides such as Al₂O₃, Y-TZP, YAG, Al₂O₃-ZrO₂ and Mullite were successfully superfast densified by SPS under the conditions
of heating rate as high as 600℃/min, no keeping time at the sintering temperatures above 1200℃, and then fast cooling to 600℃
within 3 minutes. The superfast sintering samples show high densities, fine microstructures and excellent mechanical properties. The fracture toughness K_1c
of 20mol% Al₂O₃-ZrO₂(3Y) samples sintered by SPS at >1250℃ for 2 min is higher than 6MPa·m^1/2. The reaction sintering of ZrO₂-
mullite could be completed by SPS at 1530℃ for 3 min.The SPS (Spark Plasma Sintering) process is a new materials synthesis processing technology recently developed by Sumitomo Coal Mining Co.Ltd.,
Japan. Some oxides such as Al_2O_3, Y-TZP, YAG, Al_2O_3-ZrO_2 and Mullite were successfully superfast densified by SPS under the conditions
of heating rate as high as 600℃/min, no keeping time at the sintering temperatures above 1200℃, and then fast cooling to 600℃
within 3 minutes. The superfast sintering samples show high densities, fine microstructures and excellent mechanical properties. The fracture toughness K_1c
of 20mol% Al₂O₃-ZrO₂(3Y) samples sintered by SPS at >1250℃ for 2 min is higher than 6MPa·m^1/2. The reaction sintering of ZrO₂-
mullite could be completed by SPS at 1530℃ for 3 min.

It was assumed that the purpose of strengthening and toughening of ceramic materials can be achieved by adopting
ceramic grain boundary stress designing to make artificially physical mis-match in ceramic materials, which induces a suitable stress state, as the role of absorption, consumption or
transference for applied energy. The experimental results of some systems showed that this assumption is reasonable and feasible, as
well as possible to provide a adaptable way for fabricating ceramic materials with lower cost.

The authors improved the crucible used in the hydrothermal synthesis of powders and discussed the experiment results of this method and the relationship betttfeen the form of used precursors, reaction temperature, time and phase, Particle size and morphology of the products. as well as made a comparison with common hydrothermal synthesis.The authors improved the crucible used in the hydrothermal synthesis of powders and discussed the experiment results of this method and the relationship betttfeen the form of used precursors, reaction temperature, time and phase, Particle size and morphology of the products. as well as made a comparison with common hydrothermal synthesis.

The effects of mixed rare earth oxides on densification, microstructure and mechanical properties Dy-β-SiAlON ceramics were investigated. It was found that the densities and mechanical properties were improved while Dy³⁺ was half replaced by Sm³⁺, but there was no such effect found while replaced by Y³⁺. It was also observed that the growth of β-SiAlON grains was restrained while Sm₂O₃ was added.

The time-to-failure of mullite ceramics was meajsured as a function of applied stress in air,distilled water and alkaline solution at room temperature, respectively, and the mechanism of stress corrosion cracking was discussed. It is shown that absorption effect is the dominant mechanism at high stress level, while blunting effect is dominant at low stress level. In addition, crack growth parameters in the alkaline solution are different from that in water, which implies that the two media hague different solvability on the hydrate layer.

A new citrate gel-processing route to synthesize pure BMT powder at low-temperature (600℃) was proposed and investigated by XRD, DTA and
SEM methods, in which self-prepared Ta-citrate was adopted as the starting precursor. The conventional approach from high purity Ta₂O₅ powder
was also as starting material to prepare BMT powder for comparison. It was discovered that a pure BMT phase with pseudocubic perovskite strcuture was
formed at much lower temperature (600℃) and nano-particle size powder (100～200nm) was obtained by the citrate gel-process. Whereas, the synthesizing
temperature of conventional one was more than 1250℃.

(Ca__xSr_1-x)TiO₃ cell volume reduced with the increase of Ca content. This could lead to the increase of binding energy, but as shown by XPS analysis,
TiO₆ octahedral tilted and made bonds longer, thus decreased the binding energy. This observation supported the point of Myhra. Ca-added could lead to the change of
chemical potential, and cause an increase of the oxygen adsorption at grain boundaries. The varistor behavior of (Ca_xSr_1-x)TiO₃ ceramics was caused by the
shrinking of cell volume and the change of chemical environment.

The structure, TEM morphology and photoluminescence(PL) of nanocrystallites Ln₂O₃;Eu (Ln=Gd, Y) phosphers were studied. Samples were prepared by glycerin(G)-nitrate(N) sollltion combustion synthesis. The particle size of Ln₂O₃ could be controlled by different ratio of G/N.the influences of mesoscopic effect on PL of Ln₂O₃: Eu, such as the red shift of the excitation peak,the broading of emission peaks, were discussed.

The partly replacement and doping of CaBi₄Ti₄O₁₅ ceramics were investigated, and a netthigh temperature piezoelectric ceramic Ca-(Na, Ce)-Bi-Ti system was obtained. A series of doping(including one or two oxides) was developed on this new powder system. Their curie temperatures are reduced, while their d33 and oiller piezoelectric properties are improved greatly.This new system is a very promising high temperature piezoelectric ceramic material for practical application.

The dependence of chemisitry properties of elements Sn and O on the surface of oxidized Sn films on vacuum annealing was studied. By using in-situ
measurements of X-ray photoelectron spectroscopy (XPS), it was found that great number of negatively charged particles (such as O^- and O^-₂) were adsorbed on the
surface. The amount of the adsorbed oxygen particles increased with the annealing temperature (T_ann), and then the adsorbed oxygen particles became less charged. The
increase in the number of the adsorbed oxygen particles is attributed to the transition from SnO_2 to Sn₂O₃ as T_ann≤350℃. At 350≤T_ann≤400℃,
the relative content of Sn in metallic Sn phase increased suddenly with T_ann due to the transition from Sn³⁺ to Sn^0, which resulted in releasing and successively piling up of O particles adsorbed on
the surface. Moreover, SnO₂ became more stable than Sn₂O₃ in the case of higher annealing temperauters, as say T_ann≤350℃. The adsorbed states of the oxygen
particles on the surface and the correlation between the adsorbed states and annealing temperature were also discussed.

Zirconia based bioglass-hydroxylapatite coatings were prepared using slurry-dipping and sintering method. Mechanical and thermal properties of
the coatings were investigated. The results obtained in the experiment showed that the hydroxylapatite content in composite materials has great effect on
their thermal expansion properties. This is due to the main phase change from bioglass phase to hydroxylapatite phase in the microstructure. Thermal stress
in the graded coatings was theoretically calculated, which showed that the difference of thermal expansion properties between coating and substrate has
a greater effect on the thermal stress in the coating. Bonding strength between coating and substrate was tested according to
ASTM-C633, and the result is in accordance with the calculated thermal stress in the coating.

The crystallization behaviors of sol-gel TiO₂/SiO₂ composite films and the phase boundary diffusion of the film and the buffer layer were studied. 50TiO₂/50SiO₂
films annealed between 500℃ and 950℃ exhibited crytsallization in the anatase ad rutile phases. The structure of the thin film transformed from
amorphous state into anatase, and from anatase into rutile and induced the crystallization of SiO₂. For TiO₂/SiO₂ film deposited on a dense silica
and nano-porous SiO₂ surface, the diffusion of Ti can be observed in the nano-porous layer by AES. Between the film and the buffer layer carbon was also
observed by AES. SEM and EDS revealed the distribution of carbon in the thin film surface. With the increasing heat-treatment temperature in O₂ the conent of carbon decreased.

The feasibility of using the indentation test method to evaluate the adhesion property of chemical vapor deposited diamond film was investigated initially
on the basis of observations and analyses of the cracking or delamination ways of diamond films under indentation. The critical load for lateral crack initiation or
peeling-off (P_cr) and the cracking resistance (dP/dX), two useful adhesion parameters, were used to characterize the adhesion properties of diamond
films synthesized by various pretreatment methods and deposition process parameters. The relationships between adhesion properties and methane concentrations, deposition
pressures, deposition powers and residual stresses were studied. Adhesion properties of diamond films can be improved using proper pretreatment of substrate surface,
suitable methane concentration, lower deposition pressure and higher deposition power.

Sapphire (1102) ribbon and (0001) bar were prepared by tile EFG methods and its crystal defects, such as dislocation, subgrain boundary as well as faceting plane were investingated experimentally. The influence of growth process on crystal defects was discussed. It was found that crystal growth rate and the quality of seed crystals were the two critical factors ti.hich affect the formation of defects in sapphire single crystals.

The flexural strength of soda-lime glass σ_nb is inversely proportional to the theoretical stress concentration factor
of specimens K_t but the fracture stress at notch root σ_f(=K_tσ_nb) is independent of K_t. When the flexural strength follows Weibull distribution, the modulus m is a
material constant but the scale factor σ_0 changes inversely with K_t. When the flexural strength follows Gauss distribution, both
the mean value and the standard diviation of the flexural strength are inversely proportional to the K_t, but the coefficient of variation of the
flexural strength is a material constant.

The surface composition and bonding of a wide variety of SC nanometer powders were characterized by TEM, IR and XPS. The results show that oxygen mainly
exists in the form of physical adsorption for fresh SiC nanometer powder(adsorbed oxygen---78.25%, combined oxygen---21.75%). When the powder was kept in air for
a month, its O/Si mole ratio added from 0.49 to 0.70, when the powder was kept in air for two month, the O/Si mole ratio added to 0.77. The results show that the
oxidization of the powder becomes slower after a month. Oxidization of the powder is easier in wet air than in dry air. Oxygen content decreases with increasing Ar⁺
sputtering time, and oxygen is mainly distributed over the surface of the powder.

Through combustion of aluminium powder in pressurized nitrogell atmosphere, alunliniunl nitride(AIN) containing 11igher content of nitrogell ac.as prepared by self-propagating high-temperature (combustioll) synthesis (SHS) method. The effects of diluent content, additive content, nitrogen pressure, relative density of reactants, thickness of reactants on the SHS of AId under pressurized nitrogen were studied.

Interfaces in Si₃N₄ /BN_(f) composite were studied by using high resolution electron microscope (HREM). It was revealed that fibers ends, botll tops and bases, were closely bonded with the matrix grains. Fiber pull-out had hardly any contribution to the improvement in fracture toughness of the composite material. HREM observations suggested that the increased fracture energy absorbed came mainly from sliding, tearing and curving Oil (001) plane of BN fibers and debonding at the interfaces between Si₃N₄ and side surfaces of BN fibers.

Surface tension driven flow in high temperature oxide melt was visualized by means of the already proved method of high temperature in situ optical
observation. The streamlines of the steady thermocapillary convection were marked in the form of an axially symmetric pattern. The oscillation motion
of thermocapillary vortex was observed accompanied by synchronous temperature oscillations. Another type of oscillation thermocapillary convection was also
observed mainly caused by the variation of the curvature of meniscus of the melt free surface. Finally the oscillatory frequency of the convection against
the temperature of the melt was measured.

Zirconia electrolyte membrane for ceramic fuel cell application was fabricated using tape-casting process.Four fully stabilized
zirconia powders with different particle size were used. It comes out that the optimum formulation for tape casting is affected substantially
by powder particle size. With the decrease in particle size , the amount of dispersant needed increases; furthermore, the amount of binder/plasticizer
must be increased so as to devote sufficient strength and flexibility to the green tape for easy handling and storage. The slurry viscosity has an
important effects on tape casting process in order to get a good green tape. The moderate viscosity values for tape casting slips are 400～600 mpa·s
for shear rates up to 350s^-1.

The micrograph and chemical structure of the superfine borate modified by N-containing compounds were analyzed by SEM, XRD, FT-IR, XPS. The oxidation properties, rust and corrosion properties of the superfine broate modified by N-containing compounds were nil-estigated. The results indicated that the superfine borate modified by N-containing compound, ti.hich is composed of Na₂O₃.IB₂O₃0.95H₂O, possesses good anti-oxidation, allti-rust and corrosion properties.

The structure characteristic and bonding form were studied on the interface of shell and closed-shell-muscle by scanning electronic microscopy, and some principles of bionics design were proposed on implant biocerarnic.