In this paper, unlike the traditional powder metallurgy technology, the titanium hydride is directly used as the starting material to manufacture the titanium and titanium alloy. Thermogravimetric and dilatometric techniques are performed to study the dehydrogenation and shrinkage of TiH2 powders with different particle sizes. The process factors such as the sintering temperature, the sintering time, the heating rate, the compaction density, the compaction methods, and the alloy system, would affect the sintering densification of TiH2 powders and TiH2-Al-V alloy powder. The results shown that the dehydrogenation temperature of the starting and ending of the ball milling TiH2 is lower than that of the coarse TiH2 powders, the finer the TiH2 powder, the lower the temperature. The densification of TiH2 powders is easy due to the combination of dehydrogenation and shrinkage of α-Ti in one process, which creates the fresh dehydrided titanium uniform during sintering, thus leads to rapid densification and very high sintering relative density, higher than 99%. In contrast, it is difficult to achieve a full densification of TiH2-Al-V alloy powder during sintering, which requires dissolution of alloy elements during sintering above its beta transformation temperature. The sintered microstructure of Ti-6Al-4V shows the typical lamellar shaped α+β characteristics, with a uniform alloy element distribution.

Firstly, the parameters of cohesive zone model in ABAQUS software are calibrated through the cohesive constitutive model determined by cohesive potential energy, which is provided by Oriz and Pandofi（1999）. Then, the validity and liability are verified by the single element example which compares extended finite element simulation with experimental results. Lastly, it puts forward the model of FEM based on the highway pre-sawed cracks. The curve of CMOD with changing temperature is obtained, and the curve can be divided into three stage segments. The middle stage segment changes dramatically for the local cracking in the crack tip field between asphalt surface and base. The research results illustrate the cracking mechanisms of asphalt pavement under changing temperature.

The micro-sized silver used for solar cell grid electrode was obtained from silver nitrate via chemical reduction under ultrasonic wave and alkaline environment using polyethylene glycol (PEG-6000) as dispersant and alcohol as surfactant, and after agitation, the sol was filtered, washed and dried at constant temperature. The PEG and alcohol protective mechanism in the preparing process of spherical silver particles was studied. Effects of the amount of dispersant, pH, dosage of alcohol, were investigated. The silver powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Results show that with 0.35mol/LAgNO3 solution, 25mL ethanol, T = 40°C, pH = 8 and 10min ultrasonic wave, spherical silver power about 1.38 ~ 2.11μm with narrow particle size distribution was fabricated. The paste prepared with ready-made silver powder was printed on the silicon and the contact resistance is very low, indicating the electrical property of the prepared silver is qualified for solar cells.

Fe, N)-codoped TiO2 were prepared by calcining the Fe-doped TiO2 samples accomplished by precipitation method in the nitrogen atmosphere, and the photocatalytic properties of (Fe, N)-codoped TiO2 at different temperatures were investigated. The samples were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and ultraviolet-visible (UV-vis). The results show that the (Fe, N)-codoped TiO2 powder samples calcined at 600°C are dispersed well with more hydroxyl groups on its surface. The absorption edge of the (Fe, N)-codoped TiO2 is 429nm due to the effects of mixed crystal, which means the improvement of photocatalytic capability.

Preparation of aqueous ceramics slurry with high solid volume and low viscosity is premise and key step of gelcasting, and dispersant play important role in slurry preparation. In this paper, triammonium citrate (TAC) was used as dispersant of PMN-PZT piezoelectric ceramics slurry, the effects of TAC on slurry stability and rheological properties and dispersion mechanism of TAC were investigated by sedimentation test, viscosity, scanning electron microscopy (SEM) and FTIR analysis. The SEM results indicated that TAC could reduce the agglomeration of powder particles and make ceramic particles well-dispersed. FTIR indicated that strong chemical absorption occurred between TAC and PMN-PZT powder, and slurry stability and rheological properties of PMN-PZT slurry were improved through electrostatic interaction of TAC. The effects of TAC on sedimentation volume and viscosity have similar tendency. When TAC content was 7.5vol% and pH of slurry was about10, PMN-PZT slurry suitable for gel-casting could be acquired.