The corrosion of pure nickel and chromium and of three NiCr alloys containing 10\%, 25\% and 50\% Cr in a HCl--containing oxidizing atmosphere with KCl--ZnCl$_{2}$ deposit at 600℃ was investigated. All the materials suffer from accelerated corrosion with respect to their corrosion in the same atmosphere in the absence of chloride deposit. In particular, both metals corroded more quickly than the three NiCr alloys especially during the initial stage. The scales formed on the five materials were very porous with cracks and composed of oxides or/and chlorides of both metals as well as some Cr--Zn/K spinel. Moreover, the chlorides of both metals were found at the metal--or alloy--scale interface. Finally, the corrosion mechanism was discussed in terms of accelerated oxidation induced by chlorides.

The oxidation behavior of powder metallurgical Ag--Cr ~alloys ~at ~700 and 800℃ ~in ~0.1~MPa O{2} was studied. PM Ag--35Cr alloy formed complex scale including silver metal, Cr$_{2}$O$_{3}$, AgCrO$_{2}$ and internal oxidation zone of chromium. A continuous layer of Cr$_{2}$O$_{3}$ under an external layer of AgCrO$_{2}$ formed on the PM Ag--69Cr alloy. The internal oxidation of chromium was suppressed in this alloy. The oxidation of PM Ag--Cr alloys was strongly affected by the restriction to chromium diffusion due to the presence of two phases and by the relatively large size of the chromium particles, which restrained the formation of exclusive Cr$_{2}$O$_{3}$ scales which restrained the formation of exclusive Cr$_{2}$O$_{3}$ scales at the chromium contents 69\%. The appearance of pure silver on the PM Ag--35Cr alloy was a result of the stress resulting from large volume change caused by internal oxidation.

The solidification behavior and structural evolution of Cu--Pb monotetic alloy (Cu--25\%Pb, Cu--37.4\%Pb and Cu--40\%Pb, mass fraction) were investigated by means of combination of melted glass denucleation and cyclical superheating, and the relationships between undercooled microstructures and wear rate were studied. The results show that during the solidification of undercooled Cu--25\%Pb hypomonotectic melt, $\alpha$(Cu) nucleates first, whole solidification course follows the mode of the undercooled single--phase alloy melts, and the structures undergo the evolvement processes in which fine dendrites change into a kind of quasi--spherical grain with undercooling increasing. During the solidification of undercooled Cu--37.4\%Pb monotectic and Cu--40\%Pb hypermonotectic melt, $L_{2}$ liquid phase nucleates ahead of $\alpha$(Cu), and the monotectic microstructures and the hypermonotectic microstructures within undercooling range can be obtained, respectively. The wear rate of Cu--37.4\%Pb monotectic alloy reduces gradually with the increase of undercooling.

A finite element analysis of a unit cell modeling of electrical characteristics of SiC three dimensional networks is presented. A reasonable theoretical formula describing the resistivity of SiC 3--D networks was established. Calculated results showed that a uniform electrical current distribution of SiC 3--D networks can be obtained when uniform voltages are applied. The networks with a diamond unit cell have 3--D connectivity characteristics, while the networks with a rectangular unit cell have one--dimension characteristics. Ceramic networks with a diamond unit cell still keep the 3--D connectivity characteristics when its $L/S\gg$1 cm$^{-1}$.

Polycrystalline FeS$_{2}$ thin films were prepared by annealing the iron films in sulfur atmosphere. The crystal structure was determined and the orientation texture was discussed for the FeS$_{2}$ films prepared on the substrates with different structures. The results show that the texture distribution of the film can be controlled in a certain extent using the substrate with different crystalline types. The FeS$_{2}$ films prepared on the substrates Si(100), Si(111) and Al have only one preferred orientation (200), while those on the microcrystalline TiO$_{2}$ substrates share two preferred orientations (200) and (220). There is an insignificant effect of amorphous glass substrates on orientation distribution in the film growth. Various substrates induce different interfacial mismatch between the film and substrate, and result in the changes of lattice distortion degree, grain size and texture distribution. The film surface energy and natural orientation of grain growth mainly dominate the resultant distribution of crystal orientation and induce small lattice distortion and fine grains in the film if the substrate is amorphous or has high interfacial mismatch. Besides the film surface energy and natural orientation of grain growth, the interface strain energy participates in the domination to the resultant distribution of crystal orientation and tends to induce strong lattice distortion and coarse grains if the substrate is crystalline and has low interfacial mismatch.

Solution polymerisation was employed to prepare the modified polymethacrylate resin as the polymer for coating on coronary stents with drug elusion. Both the polymer and the drug elusion coatings on the stainless steel were prepared by the dipping technology. The composition of copolymer was analyzed by IR and NMR techniques, and the physical property, the biostability and the drug elusion characteristic were also evaluated by Ultro--spectrophotometer, HPLC. The results show that the modified polymethacrylate resin has favorable biostability, and the addition of MAA and BMA provides the polymer with improved physical property, especially the adhesive force between the polymer coating and the stainless steel substrate. The drug elusion coating has paclitaxol releasing function, and its releasing time is more than 15 days. The manufactured paclitaxol--releasing polymethacrylate resin coating can be used as the coronary stent coating.

YSZ--Al$_{2}$O$_{3}$ composite membranes with different composition were introduced to reduce the stress occurred during heat treatment, which could make the membrane have defects and microcracks. The degree of components and the thickness of the composite membrane were considered simultaneously. The data showed that linear expansion coefficient and sintered shrinkage increased with the increase of YSZ content. The sintered shrinkage was an important factor to choose the composition. Two composite membranes with 20\% (volume fraction) and 80\% of YSZ content were prepared. And the pore sizes of two composite membranes are 0.72 $\mu$m and 0.36 $\mu$m, respectively. The composite membrane is an excellent microfiltration membrane and a support for the preparation of YSZ ultrafiltration membrane and nanofiltration membrane.

A novel super--hybrid composite was prepared with foam SiC ceramics, high performance fibers and modified phenolic resin. The surface treatment of fibers and foam SiC ceramics and interface adhesive states between matrix and foam ceramics were investigated with mechanical properties of super--hybrid composite and SEM analysis. The results show that interfacial cohesive state between foam SiC ceramics and resin is better when the surface of foam SiC ceramics with porous transition layer or particles of SiC than that when the surface of foam SiC ceramics with whiskers or untreated. Flexural strength and modulus of super--hybrid composite can be improved greatly by the better interfacial control. And the increasing rate of flexural modulus is more than that of flexural strength. After high silica fiber is treated by coupling agent, excellent interfacial cohesion and flexural strength of super--hybrid composite are obtained.

Y$_{2}$O$_{3}$ nanopowders were synthesized using a chemical precipitation process from coarse yttira Y$_{2}$O$_{3}$ powders, ammonium hydro--carbonate, nitric acid and aqueous ammonia. X--ray diffraction (XRD) was used to determine the phase constitution of the yttria powder. Morphology and size of the powders were observed by transmission electron microscope(TEM). Size distribution of the powder was analyzed using Image Analyser. The precipitation processing parameters and calcination temperatures have a significant effect on the particle size and size distribution of the synthesized Y$_{2}$O$_{3}$ nanopowder, and thus influence the density and transparency of the sintered ceramics. The Y$_{2}$O$_{3}$ nanopowder produced by calcining the precursor (obtained at a pH of 8) at 1000℃ is 30 nm in particle diameter, spherical in shape, well dispersed, and narrow in size distribution. This Y$_{2}$O$_{3}$ powder can be sintered into transparent body by a vacuum sintering at 1700℃ for 4 h without any additive.

The local brittle zone phenomena of pipeline X70 steel were studied by means of simulated heat affected zone with the emphasis on the forming of granular bainitic in the intercritical coarse grained region and its influence on the toughness. The experimental results showed that $M$--$A$ constituents mainly distributed at prior austenite grain boundaries ~at ~second ~peak ~temperature of 780℃, large particle $M$--$A$ constituent and fine grain bainitic zone were formed at prior austenite grain boundaries at 840℃, and $M$--$A$ constituent distributed uniformity at 900℃ with the disappear of prior austenite grain boundaries which suggested that the austenite is mainly nucleared and grows at CGHAZ grain boundaries. Re--heat brittle phenomena was found in CGHAZ of X70 pipeline steel at an second peak temperature of $A_{\rm c1}$--840℃ which is narrower than $A_{\rm c1}$--$A_{\rm c3}$ and is mainly caused by $M$--$A$ constituents distributed in chain at prior austenite grain boundaries.

Well--aligned carbon nanotubes (CNTs) were synthesized on porous silicon by electron cyclotron resonance chemical vapor deposition (ECR--CVD). CH$_{4}$ and H$_{2}$ were used as the source gases and Fe$_{3}$O$_{4}$ nanoparticle as the catalyst. The effects of process parameters such as gas composition, working pressure, temperature and deposition time on CNTs growing characteristics were investigated. The morphology and structure were evaluated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectrum. The results show that the gas composition and working pressure influence the concentration of carbon radical in the chamber, which may influence growth rate, density and aligned growth of CNTs; The temperature controls the diameters of CNTs by changing the size of catalyst but CNTs can’t tend to aligned growth at lower temperature; CNTs become longer and longer according to the deposition time first, but then stop growing after a certain time.

Investigation of optical and electrical properties of poly[(3--acetylpyrrole--2,5--diyl)p--(N,N--dimethylamino)benzylidenequinomethane]] (Papdmabeq) thin film implanted by low energy ion was carried out. The influence of ion implantation on the parameters that were related to the third--order nonlinear optical susceptibility was especially studied (energy of nitrogen ion 10$\sim$35 keV, while the dose 1.2$\times$10$^{16}\sim$2.2$\times$10$^{17}$ ions/cm$^{2}$). The results show that the conjugated chain of the polymer increases when ion implantation is performed, its film surface conductivity is 5 order of magnitude higher than that of the intrinsic sample when the dose is about 2.2$\times$10$^{17}$ions/cm$^{2}$ and energy 25 keV, and when the dose is about 2.2$\times$10$^{17}$ions/cm$^{2}$ and energy 35 keV, its optical band gap is 1.340 eV, less than that of the intrinsic sample (1.626 eV).

Stress corrosion cracking (SCC) or static fatigue fracture of a BaTiO$_{3}$ ferroelectric ceramics in moist atmosphere, water, silicon oil and formamide was investigated at constant load test using a single--edge notched tensile specimen. The result showed that SCC could occur in these four environments. The fracture surface overloaded in air is transgranular brittle fracture, and the fracture surfaces of SCC in moist atmosphere, water, silicon oil and formamide are mainly transgranular but there is a small intergranular region. The normalized threshold stress intensity factor of SCC was 0.78(in air), 0.63(in water), 0.66(in silicon oil) and 0.82 (in formamide), respectively, and the fracture toughness is 1.29$\pm$0.14 MPa$\cdot$m$^{1/2}$.

Porous $\beta$--TCP/HA biphasic bioceramics were sintered by a microwave processing system to improve both the mechanical strength and the bioactivity. Through the optimization of sintering conditions, such as the sintering temperature, the holding time and the heating speed, porous bioceramics with average crystal size of 400 nm, porosity of 48\%, and tensile strength of 1.10 MPa were prepared. To achieve similar linear shrinkage and tensile strength, the microwave sintering temperature reduced about 100℃. The comparison between conventional sintered specimens and microwave sintered specimens showed that the latter exhibit smaller grain size and higher tensile strength. After immersion in simulated body fluid, the amount of bone--like apatite formed on the specimens sintered by microwave processing system was more than that of specimens sintered by conventional furnace. The results indicate that it is possible to improve both the mechanical strength and bioactivity of Ca--P bioceramics by microwave sintering.

Influence of the current density on the structure and properties of porous titania coatings prepared by the compound process (pre-oxidation and micro--arc anodic oxidation) was studied by means of SEM, EDS, X--ray diffraction and micro--hard meter. The morphologies, phase structures, element compositions and micro--hardness were tested. The results show that there are obvious effects of the current density on the structure and properties of titania coatings. The coatings are mainly composed of anatase when the current density is kept in a low level (20 mA/cm$^{2}$). When the current density increases, anatase decreases and rutile increases. The pores diameter, surface roughness and hardness of the coatings increase, and the molar ratios of Ca/P are changed at the same time. When the current density are 20, 40, 60, 80 and 100 mA/cm$^{2}$, the molar ratios of Ca/P are 1.22, 1.60, 1.89, 2.01, 2.12, respectively. The porous titania coating containing Ca and P with preferable microstructure and property can be prepared when the current density is at 40 mA/cm$^{2}$.

Zr--Ti--based alloys were designed according to the electron concentration ($e/a$) and average atomic size rules. All the compositions satisfy the same electron concentration $e/a$=1.5 and average atomic radius 0.1496 nm as those of the Zr$_{60}$Al$_{20}$Ni$_{20}$ bulk metallic glasses (BMG). A new technique, laser--induced combustion synthesis (LCS) technique, was applied to fabricate these alloys. The LCS products mainly consist of intermetallic phases, but in Zr$_{55}$Ti$_{10.8}$Al$_{17.1}$Ni$_{17.1}$ and Zr$_{50}$Ti$_{21.6}$Al$_{14.2}$Ni$_{14.2}$ the amorphous phases are found. The hardness and tribology characters are closely related to the phase content. In general, the more the amorphous phase, the lower the hardness and the higher the average friction coefficient.