Correlation of hydrogen embritt/ement sensitivity and fracture behavior was investigated by means of tensile tests and fractographic examination in a precipitation strengthened austenitic alloy with and without hydrogen. Additionally, slip bands during tensile deformation were observed in order to determine the effect of hydrogen on localized plasticity and microcrack nucleation. The results show that the fracture mode of the precipitation strengthened austenitic alloy exhibits dramatic transition from dimple fracture in uncharged specimens to the mixed mode with dimple, intergranular and slip band fracture in charged specimens. As for the reason, it can be related to not only the slip planarity and localization induced by hydrogen but also the dislocation pile-up and hydrogen accumulation formed at the sites of grain boundaries, twin boundaries and intersecting slip bands.

A kinetic Monte Carlo model describing the three–dimensional thin film growth on square lattice substrates was presented, in which the two–dimensional Ehrlich–Schwoebel barrier for an adatom to diffuse down a surface step was taken into account. Three principle dynamic processes, namely deposition, diffusion and re–evaporation were included in the description of surface motion of the adatoms. It is considered that these three dynamic processes are interact on each other and will occur randomly according to their rates. Three growth modes and corresponding island morphologies under different growth conditions were simulated. By analysing the simulate results, It is educed that the important influence of Ehrlich–Schwoebel Barrier on surface morphology, and under the action of Ehrlich–Schwoebel Barrier, the temperature of substrate and deposition rate also play an important role in thin film growth modes.

The mechanical behaviors during crimping and expansion as well as the flexibility of coronary stent made of nickel-free stainless steel were simulated in this paper. The longitudinal recoil, radial recoil and the deformation behavior in crimping and expansion for different stent mesh width were investigated. The moment-deflection curve and flexibility of the stent were calculated. The results show that the nickel-free stainless steel stent has smaller longitudinal and radial recoil, and excellent flexibility in elastic bending deformation process.

The effects of Y on mechanical properties of Mg–8Al–2Sr–xY alloys at elevated–temperature were investigated by optical microscopy (OM), scanning electron  microscopy (SEM) and energy dispersive spectroscopy (EDS), high resolution transmission electron microscopy (HRTEM), X–ray diffraction (XRD) and tensile testing. Results show that adequate Y addition can refine the grains of Mg–8Al–2Sr alloy distinctly, change phase composing, restraine β–Mg₁₇Al₁₂ effectively and heat–resistant Al₂Y and Al₂Sr came forth as a result and improve the elevated temperature mechanical properties. But superabundant Y addition results in uneven microstructure and composition and the decrease of the mechanical properties.

MB2 alloy and LY12 alloy were welded by vacuum diffusion welding. The element distribution and intermetallic compounds at the interface were characterized by Scanning Acoustic Microscopy, SEM, XRD and EPMA. The results show that the welding interface bonding rate can be improved with the welding temperature, and the welding interface bonding can be achieved completely at the condition of 3MPa, 100min and 480 ". The solid solution Al(ss, Mg) and Mg(ss, Al) formed at the interface. Also, Al12Mg17, AlMg and Al3Mg2 formed at the interface, where the joint fracture occurred, and the thickness of the intermetallic compounds increase with increase of the temperature. The reaction layers of MB2 and LY12 welding joints can be divided into the following stages: effective physical contact, solid solution
generating, intermetallic reaction layer generating, and intermetallic layer growing.

Dynamic precipitation of 7050 Al alloy on the different deformation temperature was investigated. The results show that dynamic precipitation of MgZn2 phases can not affect the jagged fluctuations of the true stress-strain curves, and the deformation accelerated the dynamic precipitation. With increasing of deformation temperature, partial spherical precipitates become to rod-like precipitates, and the size of the precipitates increased while the quantity reduced. Large rod-like MgZn2 precipitates are fragmented during the deformation at 450 ℃. Simultaneity, the density of the dislocation also decreased, and the dislocation cells transform into the discrete dislocation. The precipitates pin the dislocations and prevent the grain boundary impingement. The precipitates have mainly the metastable η phase and
equilibrium η phase, and can not induce the micro-crack.

B–doped TiO2 was prepared via sol–gel method, and was characterized using powder X–ray diffraction (XRD), scanning electron microscope (SEM), X–ray photoelectron spectrum (XPS), FT–IR, and N2 adsorption (BET). The results show that B doping inhibited growth of TiO2 crystal, and no apparent impact on surface morphology of TiO2 particles was observed. The doped boron mainly occupy the internal space of TiO2 crystalline structure, existing in the form of B–O–Ti structure. The samples doped with 3% (mass fraction) boron have the optimal performance of photocatalytic degradation of methyl orange. N2 adsorption isotherm showed that the BET surface area and average pore size of 3% B–TiO2 are 127.84 m2/g and 10.53 nm, respectively.

Pure nano TiO2, N doped, Fe doped, and N and Fe co-doped nano TiO2 were prepared by alcohol-thermal method using butyl titanate as Ti sources. Its crystal structure, surface morphology, specific surface area, UV-Vis. absorption, photoluminescence and photo-catalytic activities of hydrogen evolution were characterized. The results show that all the TiO2 samples own a pure anatase phase with the average diameter of about 20 nm after calcinations at 500 , and distribute uniformly as the prismatic type of particles. N and Fe co-doped TiO2 exhibits higher visible light activity, the optimal doping amount of N and Fe is 5.0% and 2.0% respectively, which can make the absorption wavelength of TiO2 shift to 510nm compared with that of pure TiO2. N and Fe co-doping can generate the impurity levels in the
band gap of TiO2, leading to a good visible light response. The recombination of photo-excited electrons and holes is restrained by N and Fe co-doping. N and Fe copdoped TiO2 displays higher catalytic activity under visible light irradiation (λ >400 nm), the hydrogen evolution rate is 299.2 μmol·g−1·h−1 by water splitting.

The degradation and restructuring mechanisms of furan units were investigated by Gaussian software based on the Density Functional Theory (DFT) in this paper. Results show that: (1)The carbon-oxygen bonds on furan ring are active sites during pyrolysis. Therefore, the protection of active carbon-oxygen bonds will be beneficial to improve heat-resistance of furan resin and provide novel ways for modification of furan by ceramic particles. (2)The ring-opening products will change into six-membered carbon rings trough rearrangements. The reservation and transformation of residual resin groups contribute to increase carbon yield ration. (3)The emergence and migration of hydrogen radical are basic characteristic of ring-opening reaction and structural re-arrangement.

The effect of the isothermal heat-treatment on semi-solid microstructure of AZ61 rare earth alloy were investigated. The results show that with increasing of the isothermal heat-treated temperature, the serious dendritic in the microstructure of initial cast alloy turned into semi-solid non-dendritic tissue after the isothermal heat-treatment. This microstructure evolution includes coarsening, microstructure separation and spheroidizing. In the process of isothermal heat-treatment , the element La is very important to refine alloy’s organization.It hinder aggregating and associating of the particles of solid phase , inhibit further growing of the particles of solid phase and make the microstructure of non-dendritic tissue more smaller. After the isothermal heat-treatment for different time, the irregular large block tissue begin
spheroidizing and form many nearly spherical particles. But when the time of isothermal heat-treatment exceed a certain range, the spherical particles began to coarsen and many liquid islands formed in the particles. The spheroidizing of dendritic microstructure includes the disappearance of secondary dendrite wall and Ostwald ripening process.

The microstructural characteristics and mechanical properties of a V-microalloyed TRIP steel after cold rolling and continuous annealing were investigated. The results show that the microstructure of TRIP steel with bainitic ferrite matrix is composed of bainitic/martensite and a small amount of retained austenite. With increasing the bainite holding time, the yield strength and elongation rate of the tested material increase, and the tensile strength decreases. The blocky retained austenites mostly turn into 50-90 nm flims between bainite laths and the volume fraction of retained austenite increases. When holding at 400^oC for 180 s, a relatively low tensile strength (960MPa), high yield strength (765MPa) and elongation rate (22.0%) of continuous annealing sheet steel can be obtained, and strain-hardening exponent (0.20), anisotropy exponent (0.94) and tensile strength–plastic performance (21120 MPa.%) are excellent.

The practically magnetorheological rubbers were fabricated, and the influence of carbonyl iron powders (CIPs) contents, carbon black contents, softeners contents and modified CIPs by different coupling agent on the physical and mechanical properties and the magneto-rheological performance were investigated in this paper. The results show that for the magnetorheological rubbers made from the NR/SBR blend, the samples with 300 phr carbonyl iron powders, 40 phr carbon black, 15 phr softeners and utilizing silicane coupling KH-570 modifying CIPs have the best physical and mechanical properties and the best MR effects. It results from the comprehensive effects of modifying by coupling with the reasonable structure, strengthening by the carbon black and toughening by the softener, etc.

Nano-sized hydroxyapatite(HA) powder was prepared by means of liquid precipitation method and its crystal structure and the characteristic were analyzed using X-ray diffraction and SEM. The effects of reaction temperature, pH value and aging time on the Powder particle size and phase composition were investigated. The results show on condition that value the reaction temperature is 90^oC, pH value is 10 and the aging time is 12 h, the pure and integrate HA crystals with average diameter of 70 nm can be gained.

Multi–walled carbon nanotubes (MWNTs) were modified with different approaches to produce carboxylated carbon nanotubes (MWNTs–COOH), covalently functionalized carbon nanotubes (MWNTs–NH2), noncovalently functionalized carbon nanotubes (MWNTs–PPA), and hybrid functionalized carbon nanotubes (MWNTs–COOH–PPA), respectively. These functionalized MWNTs were respectively incorporated into polyurethane (PU) with various mass fraction to prepare four kinds of PU composite. The mechanical and thermal properties of these composites were tested by means of universal testing machine and thermal gravimetric analyzer. The results show that by grafting few functional groups onto the MWNT surface to prevent the detachment of noncovalent wrapping, hybrid functionalization not only improves the dispersion of MWNTs in the matrix, but also retains the interfacial interactions between them. Therefore the best reinforcement is achieved. Addition of heat–resistant MWNTs increases the thermal deposition temperature of PU matrix, and the increase amount slightly varies with functionalization
approaches. MWNTs–COOH–PPA/PU has the best mechanical performance. Its tensile strength increased 104% compared with pure PU at 0.3% MWNTs loading. Its thermal decomposition temperature is identical to that of MWNTs–COOH/PU, better than that of pure PU, but lower than that of MWNTs–NH2/PU and MWNTs–PPA/PU.

The dynamic recrystallization behaviors of low carbon Q690qENH high–strength bridge steel were investigated by hot compression deformation using MMS–300 thermo–simulation machine. The results show the softening of low carbon Q690qENH high-strength bridge steel is mainly controlled by dynamic recovery during hot rolling deformation and the dynamic recrystallization occurs obviously at low strain rates of 0.1 s⁻¹ and 0.2 s⁻¹. The stress factor was modified as 0.0099 MPa⁻¹, the dynamic recrystallization activation energies were gained, and the dynamic recrystallization kinetics model was established. The expression of ε_c=0.72ε_p was determined using P–M–K method. Correlations between peak strain and Z/A are power function, and dynamic recrystallization critical strain model was established calculation values of which are good agreement with evolution of microstructure during hot deformation. Effects of temperature on migration–rate of interface were also investigated during dynamic recrystallization.

The Fe/Al2O3 composites with different proportions were prepared by sintering buried in the graphite, the microstructure and properties of Fe/Al2O3 composites were analyzed. The results show that the bending strength and fracture toughness of Fe/Al2O3 composites increase with Al2O3 percent, and then decrease. The bending strength and fracture toughness of Fe/Al2O3 composites reach respectively 602.49 MPa and 9.33 MPa·m1/2, when Al2O3 percent(mass fraction) is 70%. The hardness of Fe/Al2O3 composites decrease with Al2O3 percent, and then increase. The shell composed of FeO and FeAl2O4 formed around Fe particles in the sintering process. Micro cracks exist between the shell and Fe particles. The external stress was cut by the shell and the micro cracks between the shell and Fe particles, then the fracture toughness of Fe/Al2O3 composites enhance greatly.

Cultivated L929 cells were fostered by Ag-Pd alloys leaching liquor, Ni–Cr alloys leaching liquor, Co–Cr alloys leaching liquor, self-made 2# alloys leaching liquor (each group sample capacity is 8). Cultivated L929 cells by RPMI 1640 cell medium containing 10% fetal calf serum were taken as the negative control. The cell proliferation rates were detected by MTT, the activity of caspase–3 after 4 h, 7 h, 24 h, 48 h was calculated. The cells condition after 48h was observed by fluorescence microscope. To analyze the relationship between dental alloys biocompatibility and apoptosis correlation factor caspase–3 it was assisted by time gradient. The results show that cell quantity of each group are difference, there are lots of apoptosis cells in each group, but obviously different, orange dead cells can be seen in Ni–Cr alloys group after 48h. Cytotoxicity of each group is grade 0, the order of cell proliferation rates of groups is: Co–Cr alloys group>2# alloys group > Ag–Pd alloys group > Ni–Cr alloys group. The activity of caspase–3 in each group is obviously different (P < 0.01). The order from high to low is: Co–Cr alloys group > 2# alloys group > Ag–Pd alloys group > Ni–Cr alloys group. The activity of caspase–3 on the spot of 4 hour, 7 hour, 24 hour and 48 hour is obviously different (P < 0.01). The order from high to low was: 4 hour, 48 hour, 7 hour, 24 hour. The order of these dental alloys biocompatibility from high to low
is: Co–Cr alloys group > 2# alloys group > Ag–Pd alloys group > Ni–Cr alloys group. Biocompatibility is mainly affected by Ni and Ag ions. Detecting dental alloys biocompatibility by caspase–3 assisted by time gradient, the result is the same as that by MTT.

The mechanical properties of extruded AZ31B magnesium alloy sheets were investigated by conducting tension and compression experiments along with three different directions align in the sheet plane in this paper. The results show that extruded magnesium alloy sheets show high anisotropy and strong tension-compression asymmetry. The in-plane tensile yield stress in the extrusion direction (ED) is much bigger (about 2 times) than that of compression in the same direction and tension or compression in other directions. The tensile yield and ultimate strength in the 45o direction are smaller in some extent, while the elongation is the largest. The tension-compression asymmetry include the difference in tensile and compressive initial yield stresses (yield asymmetry) and plastic flow stresses (flow asymmetry), the compressive hardening curve turns to be unusual S-shape. The deformation mechanism which causes material anisotropy and tension-compression asymmetry was discussed based on the crystal plasticity.