Fabrication, mechanical properties and toughening mechanisms of Laminate-structure ceramic composites with weak or strong interfaces are reviewed . Complete deflection of the propagatingcrack and internal residual stresses are the causes of the special mechanical properties of thecomposites

A two-step reaction was used for the synthesis of SiC nanorods. First, SiO vapour was generated via the silicon reduction of silica. Second, the generated SiO
vapour reacted with carbon nanotubes, which resulted in the growth of the single crystalline cubic β-SiC nanorods. The diameters of SiC nanorods ranged from 3～40nm.
A broad photoluminescence peak located around 430nm under 260nm UV fluorescent light excitation at room temperature was observed. The morphology and structure of the
nanorods were characterized by XRD, HREM and Raman spectroscopy. The growth mechanism of SiC nanorods was studied in detail.

A new type of mica-containing glass-ceramics with preferentially orientated microstructure was successfully fabricated by hot-pressing the
material after the crystallization process. The fiber texture {00l}<uvw> was identified in the material by means of X-ray diffraction analysis(XRD).
The space orientation distribution function of grains was determined as f(θ)=1-Aexp^-B/θ. As the deformation amount of hot-
press increases, the preferential orientation degree increases to a certain value and then keeps constant. However, the flexural strength and fracture
toughness of the material continuously increases with the increase in the deformation amount of hot-pressing.

anocrystalline titania powder was prepared by the hydrolysis of titanium butoxide. The grain sizes of the powder calcined at 500～800℃ were measured by XRD. It was
found that the thermal stability of nanosized titania powder was improved by adding 0.4wt% rutile. Meanwhile, the powder compacts (green density was 68.3%) were
sintered at 750℃ and 800℃ under 30MPa, 57MPa and 200MPa, respectively. The microstructural development was studied by Poresizer, Pycnometer and SEM. Because
of the high pressure which increases intrinsic driving force for the diffusional transport of the pores, the densification process of hot-pressed samples commences at 750℃.
After the samples were sintered at 200MPa/800℃, the relative density was about 97.2%. Furthermore, the interagglomerational pores with size of 3～15nm could be
found in the samples, even if high pressure was used. Probably it is the main reason that the nanosized titania could not be densified thoroughly at low temperature.

The microstructure and mechanical properties of liquid phase sintered SiC followed by post-hot isostatic pressing (HIP) were studied. It is indicated that the effect of post-HIP treatment is changed with the variation of
sintering aids and temperature of liquid phase sintering. After Ar-HIP treatment, the density of SiC is increased and the inside pores are
diminished, but grain growth is depressed. Besides the advantages of the Ar-HIP, N₂-HIP can modify the surface state because of the reaction
between SiC and N₂ so that the mechanical properties are improved. Microstructure analysis has shown that after N₂-HIP treatment,
grain size is decreased and the density is increased. Meanwhile, the results of post-HIP treatment are highly affected by the microstructure
of the liquid phase sintered SiC. When the sintering temperature is relatively lower and the grain size is smaller, after post-HIP treatment, esp.
N₂-HIP treatment, bending strength and fracture toughness of the liquid phase sintered SiC are improved greatly.

The strength of synthetic and natural diamonds was measured as a function of temperature by using the soft impressor/slider technique.The results showed that the strength of diamond measured by using the soft impressor/slider technique at room temperature was consistent with that measured by using the normal method.
At elevated temperatures, the fracture behaviour of diamond depended on temperature, mean contact pressur and the coefficient of friction. Two types of fractures were observed, (111)
cleavage cracks were associated with high mean contact pressure and low temperature, whilst strain induced cracks were produced on (110) planes and associated with low mean contact
pressure and high temperature. A schematic map was plotted out to illustrate the fracture behaviour of diamond as a function of temperature and mean contact pressure.

Al₂O₃/TiC composite ceramic tapes were prepared by tape casting. After die, binder removal and hot-pressing , the multilayer composites
were acquired . Several factors effecting the viscosity of slurries,such as the ratio of TiC and Al₂O₃,values of pH and dispersant concentration,
were discussed. The processing of organic additive removal was analysed by TGA . The microstructure of tapes and multilayer composites crack propagation
effected under the stress was analysed by SEM and optical micrographs respectively. The results exhibited the fracture toughness and work of fracture
were increased effectively. The cracks propagate along the weak interface and make the stress relaxation. The multilayered structure design is an effective method for preparing advanced composite ceramic .

Orthorhombic perovskite La_0.66TiO_2.993 was Synthesized by hydrothermal method. The particle size of the product was about 300nm, and had agglomeration in some degree. The effect ofhydrothermal conditions on the syntheses was inverstigated. The results indicated that the optimum KOH/Ti, La/Ti, [Ti], temperature and reaction time are 80, 0.7, 0.1mol·L^-1,260℃ and 7days, respectively.

β-sialon powders (Si_6-z Al_zO_zN_8-z with z=3.0) were synthesized by carbothermal reductionand nitriding reaction. A sample of sialon bonded SiC was sintered at 1580～1640℃. Bulk densityof the sintered body was 2.26g/cm³, three pomt bending strength was 42.0MPa. The bendingstrength was still remained when quenching the sintered body at 1200℃ to cold water (15℃) 10times. Weight loss in flowing air at 1350℃ was less than 0.035%cm^-2.

Oriented KTa_0.65Nb_0.35O₃ thin films were grown on SrTiO₃ (111) single crystal substrates by means of potassium acetate, tantalum ethoxide and niobium ethoxide as
precursors. The presintering technological conditions were established by DTA--TGA. It was discovered that perovskite structure KTN would decompose above 950℃ to form
potassium-deficient phase K₂Ta₄O₁₁. The homogeneous, high-density, 0.2μm grain size perovskite structure KTN thin films were obtained when each layer presintered above
450℃ for 1h, multilayers sintered at 750℃ for 2h, and all of heating and cooling rate was 1～2℃/min. The film grain size increased with sintering temperature
and time, at high temperature, aggregate of grains, holes and crackles formed on the film surface. The sintering temperature must be controlled under 950℃.

Lithium and magnesium co-stabilized β/β’’-Al₂O₃ films were fabricated by the reaction between the spinel-α-Al₂O₃
composite substrate and the vapour of Li₂O and Na₂O. The experimental results show that temperature is the main factor determining the forming
rate of the β/β’’-Al₂O₃ phases which cannot be obtained when the reaction taking place at below 1100℃. Dispersive spinel in the substrate can improve effectively the formation of β/β’’-Al₂O₃ phases even at
lower temperatures. The films obtained on composite substrate exhibit favorable electrical properties which are comparable to that of
β/β’’-Al₂O₃ ceramics, although a little spinel remained in the film to some extent reduce the ionic conductivity and at the same time
increase the activation energy of the film.

Nitrogen-contatining rare earth melilite solid solutions of R₂Si_3-xAl_xO_3+xN_4-x(R=Nd, Sm, x=0, 0.3, 0.6, 1.0,
1.2; R=Dy, Y, x=0, 0.3, 0.6, 1.0; R=Yb, x=0, 0.3) were prepared in the temperature range from 1700℃ to 1800℃ by pressureless sintering or hot-pressing techniques. The
X-ray diffraction patterns of rare earth melilite and cell dimensions of melilite solid solutions were obtatined by using. Guinier-Hagg film data,
densitometer LS--18 and SCAN, SCANPI, PIRUM programs. The relationship between cell dimensions and actual Al contents for Nd-, Sm-, Y-melilite solid
solutions was also given. The results of measurements of cell dimensions showed that the lattice parameters of melilite solid solutions with the different rare earth elements but the same x value reduced with decreasing the ionic radii of rare
earth elements, whereas the cell dimensions became larger for melilite solid solutions with the same rare earth but increasing x values.

Nanoscale barium titanate powders of cubic structure were prepared from precipitate of solprecipitation method following three kinds of drying stages: freeze drying, azeotropic distillation and oven drying. Freeze drying is the most effective processing, though bothfreeze drying and azeotropic distillation stage can prevent the formation of hard agglomerates and improve the sinterability of powders. The mechanism of drying stages preventing the formation of hard agglomerates was investigated

Amorphous and crystalline nano-Al₂O₃ powders prepared by directly oxidic method and room-temperature hydrolytic method, using aluminium amalgam as precursors,
were characterized by XRD, TEM and DTA. It was found that the amorphous nano-Al₂O₃ powder only underwent γ→α transformation having no transition
phase, and the transformation process of crystalline nano-Al₂O₃ powder is γ→θ→α and incomplete. The IR measurements
were performed and the characteristic IR spectra of amorphous nano-Al₂O₃ nano γ-Al₂O₃ and nano θ-Al₂O₃ were obtained. The above results
were analyzed and discussed from viewpoints of low-temperature relaxation of amorphous nano-Al₂O₃ powder and lattice distortion of α-Al₂O₃.

Main factors influencing α(temperature coefficient of resistance) of BaTiO₃ PTCR ceramicswere analysed based on Heywang model. A relation between α and acceptor density at grainboundaries, donor density and Curie constant was given, and the experimental results are inreasonable consistence with the relation.

In the ZrO₂ ceramic systems doped with different oxides (Y₂O₃, MgO and Al₂O₃), the electronic energy spectroscopy and local density of states were calculated by a
theoretical quantum chemical method, and compared with the behaviors of electronic and ionic conduction. The results showed that for the system doped with Al₂O₃,
the energy gap near the Fermi energy level becomes smaller, so that the electronic conduction increases; the binding energy between Al and O atom increases, which
enhances the energy for vacancy migrating, the ionic conduction decreases. On the contrary, the systems doped with Y₂O₃ show a large
ionic conduction, but a weaker electronic conduction. The effect of MgO is just between above two systems. The mentioned results agree with that of references and experiments.

In order to improve wet strength of DCC-green bodies boehmite sols were added into α-Al₂O₃ suspensions. In the present paper, the properties of wet green bodies, drying
behaviours and densification process of Al₂O₃+AlOOH system were studied. The results indicated that wet compressive strength and modulus could be largely
increased with a small amount of boehmite addition. As the solid loading of boehmite is less than 3 vol% there is no influence for drying process. The α-Al₂O₃ ceramics with
very high sintered densities of 3.97 g/cm³ (99.7% TD) and homogeneous microstructure could be achieved after sintering.

The piezoelectric constants d₃₃ and d₃₁ under weak and stronger field were measured from strain S vs electric field E curves
for the converse piezoelectric effect. It was shown that on the curves there is a critical field E_b from which strains and d₃₃, d₃₁ were obviously increased, and the result was discussed in the view of reorientation of 90° domain
intrinsically existed in piezoelectric ceramics. This method of measuring d₃₃, d₃₁ is simple and convenient, as well as more
practical, especially for piezoelectric ceramic actuator, as compared with that usually obtained them from positive piezoelectric effect.

The technique of oxidation was practised successfully for manufacturing cathod materialNi(OH)₂ used for high capacity secondary battery With the determination of optimum preparation conditions including pH, reaction temperaturc and reaction timc, the high tapped densityof Ni(OH)₂ was obtained. The results of the sample measured by SEM、XRD were shown.

-Si-Al-O-N glass was used to bond and wet dense Si₃N₄ ceramic at 1450℃ and 16000℃ for30 min, respectively. The result showed that the oxynitride glass can wet well to Si₃N₄ ceramic.At 14500℃, there was obvious difference in the coefficients of thermal expansion of the glass andSi₃N₄, while at 16000℃, the difference decreased. A diffusion layer existed near the joint. Theoxynitride glass can be used to join Si₃N₄ ceramics.

With the help of an in-situ pin-disk sliding wear apparatus in scanning election microscopes (SEM), the friction and wear properties of the Al₂O₃-TiC-TiN
advanced composite ceramic under single abrasive were studied. The results show that the friction behaviors of Al₂O₃-TiC-TiN have different characteristics
in vacuum and air. At first the dominant wear mechanism is the microcutting and with the wear proceeding the brittle fracture becomes more and more important. The
experiments also indicate that the relative hardness of the abrasive has a great effect on the wear rate of this material under three-body abrasion conditions.

The changes of the thermal conductivity of CZP 、CM and CMS composition in NZP familyceramics with temperature were studied. The phonon mean free path of CZP, CM and CMScomposition was calculated. It was found that complex structure and composition of NZP familyceramics are the main reason of resulting in their small thermal conductivity.