Spherical ZnAl₂O₄ nanoparticles with uniform size distribution were synthesized by a modified polyacrylamide gel method, and three xerogel ZnAlO samples with different ratios of Zn to Al were prepared. X-ray diffraction analysis results show that the ZnAl₂O₄ powders can be obtained after calcination at 900℃ for the two xerogel samples with mole ratios of Zn²⁺:Al³⁺=1:1.8 and 1:2, respectively. Scanning electron microscope images reveal that the particle size of the sample with mole ratio of 1:2 increases with the increasing calcination temperature; when calcination at 900℃, significant agglomeration of particles can be observed. The photoluminescence emission spectrum for ZnAl₂O₄ nanoparticles detected at λ_ex= 352 nm shows a blue emission peak located at 469 nm. Finally, the chelating mechanism and luminescence mechanism of ZnAl₂O₄ nanoparticles have been discussed based on the experimental results.

Effect of solid solution-T652 treatment and pre-recovery-solid solution-T652 treatment on microstructure and mechanical properties of an extruded Al-alloy Al-10.78Zn-2.78Mg-2.59Cu-0.22Zr-0.047Sr was studied. The results show that after a pre-recovery-annealing treatment and then a post-aging at 121^oC for 24 h the grain size of the extrusion can be refined from 9.76 μm to 5.56 μm; the average grain boundary angle can be reduced from 23.59° to 17.41°, i.e.the percentage of low angle grain boundary is significantly enhanced from 53% to 67%, therewith, the dislocation strengthening is increased, and the recrystallization process may be suppressed. Compared with solid solution-T652, the pre-recovery-annealing treatment can enhance the corrosion resistance of the alloy, i.e. the maximum corrosion depth may be reduced from 125.0 μm to 91.4 μm, thus its exfoliation corrosion rating increased from EB to EA grade, while the alloy maintained a high strength. The strength of the alloy after the pre-recovery-solid solution plus T652 treatment is up to 728 MPa. Dislocation strengthening and low angle grain boundary strengthening are the main strengthening mechanisms.

The low carbon bainite steel was welded by double-sided submerged arc welding and the microstructure and low temperature toughness of the joints was studied by optical microscope and PSW750 instrumented impact testing machine. The results show that the microstructure of the weld seam consisted of acicular ferrite and granular bainite, however the HAZ shows a microstructure consisted of bainite ferrite and granular bainite. The hardness at HAZ near the weld bond is the highest and then decreases gradually approaching to the hardness of base metal. In comparison to the matrix the weld seam and HAZ show a lower toughness with a ductile brittle transition temperature at -20℃and -60℃ respectively, which may be ascribed to the occurrence of solidification segregation, highly concentrated dislocations and formation of carbon nitrides of alloying elements such as Ti and Mo at grain boundaries etc. in the weld joints during rapid cooling after welding.

Al-based composites of 25% SiC_p/6061Al and 25% Al₂O₃/6061Al were fabricated by powder metallurgy method, and then suffered from different solution-aging treatments to ensure the composites with desired strength. The effect of particle-matrix compatibility on the tensile property of the composites was investigated by tensile test and SEM observation. Results show that the low strength Al₂O₃ particles were not suitable to strengthening the high strength 6061Al matrix. The effect of particle-matrix compatibility on strengthening mechanism was discussed, and it is believed that the particle-matrix compatibility affects the composite property through the stress transfer mechanism. The relationships between particle-matrix compatibility with the particle fracture and composites yielding were revealed, It is obtained that particle cracking decreased as particle strength increase, and finally an expression to represent the particle-matrix compatibility was summed up.

The conductive amorphous carbon films were deposited on the 304SS by conventional direct current magnetron sputtering. The effect of substrate bias on the microstructure and property of amorphous carbon films were mainly investigated. The results show that the electrical conductivity and corrosion resistance are improved significantly for the carbon films coated stainless steel in comparison to the untreated ones. Specifically, when the substrate bias was -200 V the contact resistance was about 16.65 mΩcm², which may be ascribed to the highest fraction of sp² bonds under the normal compacting force of the fuel cells at 1.5 MPa. The corrosion potential of the carbon films coated stainless steel significantly increased in the simulated PEM fuel cells environment, while the corrosion current density obviously decreased, especially when the bias was -200 V the carbon film performs the best corrosion resistance, which may be attributed to its best compactness, for this case the corrosion current density is 1.22×10^-8 A/cm² and the corrosion potential is 0.25 V.

The phase change materials of fatty acid/SiO₂ composite were prepared by sol-gel method with SiO₂ as carrier material, fatty acid as phase change material, absolute alcohol and deionized water as solvent, Which then were characterized by scanning electron microscope (SEM), laser particle size analyzer (LPSA), Fourier transform infrared (FT-IR), differential scanning calorimetry (DSC) etc. The effect of the type of cores, the amount of phase change material and absolute alcohol and deionized water as well as the solution pH value and ultrasonic wave power on the texture of the prepared composites were investigated systematically. The results show that the texture of the phase change materials of fatty acid/SiO₂ composite was greatly influenced by the type of cores, the amount of phase change material and absolute alcohol and deionized water, and also related to solution pH value and ultrasonic wave power. The optimal processing parameters for preparation a good composite are: decanoic acid-palmitic acid acts as core, the mole ratio of decanoic acid-palmitic acid to tetraethyl orthosilicate is 0.4, the mole ratio of absolute alcohol to tetraethyl orthosilicate is 5, the mole ratio of deionized water to tetraethyl orthosilicate is 9, solution pH value is 4 and ultrasonic wave power is 200 W.

Slag glass-ceramics of CaO-Al₂O₃-MgO-SiO₂ (CAMS) with addition of 0-13% (mass fraction) graphite powder was prepared with tailings of East Bayun-Obo and fly ash as raw materials by the traditional melting-casting method and characterized by DTA, XRD, FE-SEM, TEM and thermal dilatometer. The effect of graphite addition on the structure and properties of the glass-ceramics was systematically investigated. The results show that the crystallization of augite phase was promoted by the increase of Fe²⁺ cations due to the reduction induced by the addition of only 5% graphite powder. As a result, the thermal expansion coefficient of the glass ceramic is increased at least by 15%. However, with the further addition of graphite powder the higher amount of iron was reduced, thereby the amount of magnetite phase decreased, which was the crystal nuclei for augite and in turn, the crystallization of augite might be suppressed. In addition, TEM observation results shows that the spherical augite crystals on the etched glass ceramics of CAMS observed by SEM is a mixer of many much smaller columnar augite crystals and a little fraction of residual glass.

Colloidal carbon microspheres were prepared from aqueous glucose solutions by hydrothermal synthesis procedure, and then submicron core/shell structured precursors of carbon spheres/ZrW₂O₈ were prepared by sol-gel method with colloidal carbon microspheres as templates to provide reactive surfaces for facilitating the deposition of nano-sized ZrW₂O₈ particles. Finally, hollow spheres of ZrW₂O₈ can be produced by calcinating the precursors at 610℃ for 10h to remove the colloidal carbon sphere templates. The final spheres ZrW₂O₈ with an average size about 3μm were proved to be composed of single phase nano-sized ZrW₂O₈ particles. Their density was measured to be 2.8 g/cm³, ca 45% lower than that of ZrW₂O₈. Along with the density, FTIR and TG-DTA results also indicate the existence of hollow structure of the spheres ZrW₂O₈, of which the thermal expansion coefficient was -11.4×10^-6K^-1 in the temperature range from room temperature to 200℃, a little higher than the theoretical value.

Precipitation behavior of second phase in two micro-carbon steels with different amounts of Nb and Ti were investigated using SEM and TEM technique. In the meanwhile, the effect of precipitates on microstructure, texture evolution and properties of the micro-carbon steels was investigated by XRD and EBSD technique. Results show that precipitates in the micro-carbon steels were mainly consisted of larger size (Nb, Ti)(C, N) composite particles and finer Nb-based carbide and carbonitride dispersed in matrix. With the increasing of Nb and Ti addition the fine second phase particles increased significantly, which strongly inhibit the development of <111>//ND fiber texture during recrystallization, especially for {223}<110> and {111}<110> orientation. As for micro-carbon steel with low content of Nb and Ti, a good combination between strength and deep drawing ability can be acquired due to the occurrence of a matrix of polygonal ferrite and martensite transformation during fast cooling process.

TiN-Cu nanocomposite films were deposited on high speed steel by arc ion plating with an axisymmetric coil magnetic field at the back of the target. The influence of the coil magnetic field intensity on the moving rate of cathode spot and arc column shape on the target surface, as well as on the surface morphology, deposition rate, nanoindentation hardness and elastic modulus of the deposits was investigated. It is shown that the emitting probability of the melt metal drops on the target decreases, and the size and quantity of the macroparticles in the deposited films reduces with the increasing coil magnetic field intensity. The deposited films consists merely of TiN phase without metal Cu phase or Cu compound and possess an obvious preferred orientation along (111) plane. The deposition rate, indentation hardness and elastic modulus of the films increase rapidly to a maximum value and then decrease slightly with the increasing coil magnetic field intensity. The maximum values of hardness and elastic modulus are 35.46 GPa and 487.61 GPa, respectively.

Surface coating with functional groups on Poly (p-phenylene terephthalaramide) (Kevlar, KF) fibers was prepared through a polymerization using horseradish peroxidase (HRP) as bioactive catalyst. The effect of this approach on integrated properties of KF fibers was investigated. The results show that the polymerization can effectively perform on the fiber surface with the presence of HRP. The HRP content affects the grafting percentage of the fiber surface. More monomer was grafted on the fiber surface with the increase of HRP content, and there with the fiber surface possessed higher amount of polargroups, higher surface free energy, and higher roughness which then resulted in the enhancement of interface adhesion between the fibers with the resin matrix of the composite fibers/resin. Besides, this HRP catalytically grafted fibers hold more or less the same thermal and mechanical properties as the original KF fibers.