The effects of Mn content on the homogenized microstructure, recrystallized fraction, precipitates and mechanical properties of 6061 aluminum alloy containing 0.15% Fe (mass fraction) was investigated. The results show that: after homogenization the main phases of the 0 Mn alloy is β-Al₉Fe₂Si₂ , and that of 0.1% Mn alloy is α-Al₈(FeMnCr)₂Si, meanwhile the blocky-shaped Al₉ (MnFe) ₃Si phase begins to appear and increases with increase of the Mn content; during aging treatment, Mn and Mg, Si form the AlMnSi and AlFeMnSi phases preferentially, which makes the main hardening precipitates reduce and weakens the strengthening effect. 0.2% Mn alloy is advisable, σ_b = 390 MPa, σ_0.2 = 330 MPa, δ = 22.2%, which is increased by 90 MPa, 55 MPa and 10% respectively, comparing with AA6061 aluminum alloys’standard mechanical properties.

AlN ceramics doped with 4% Y₂O₃ and appropriate nano-AlN powders were sintered at 1700-1850℃, the influences of Y₂O₃ and nano-AlN powders on the sintering and thermal conductivity of AlN ceramics were investigated. The results show that the Al₂O₃ powders distributed in the surface of nano-AlN took the priority to react with Y₂O₃, and second phase of Al₅Y₃O₁₂ with higher activity were gotten, which could form liquid at lower temperature. In addition, the nano-AlN powders can also promote the density of AlN ceramics. The two factors have a synergetic action on the sintering of AlN ceramics, and can improve the distribution of second phase in the microstructure of AlN ceramics. Therefore, AlN ceramics with higher thermal conductivity can be prepared at lower sintering temperature. The AlN ceramics with 4% Y₂O₃ and 1.5% nano-AlN doped, sintered at 1800℃ have a density of 3.26 gcm^-3and a thermal conductivity of 151.75 W/(mK) , and second phase distributes in the boundaries of AlN grains.

Fe nanopartilces synthesized by a DC arc-discharge plasma method were mixed with paraffin to fabricate nanocomposites. Dielectric spectra of these Fe/ paraffin nanocomposites were measured in 2-18 GHz range. Theoretical fitting of the complex permittivity spectra were carried out using the universal dielectric law, Debye relaxation theory and Cole-Cole equation, and compared with the measured ones. The results show that the universal dielectric law can be used to fit the essential outline, but Cole-Cole equation can accurately exhibit fluctuation of the complex permittivity spectra. It is also confirmed that the polarization mechanism may be equivalent to orientation polarization instead of the multi-polarization in microwave range.

A medicinal hydroxyapatite (HA) coating was prepared on the surface of Ti6Al4V alloy with micro-arc oxidation (MAO) and hydrothermal synthesis (HS) treatment. Anti-coagulation, anti-hemolysis, anti-platelet adhesion and cytotoxicity were used to test the comprehensive biocompatibility of Ti6Al4V alloy, Ti6Al4V alloy with micro-arc oxidation ceramic membrane layer and micro-arc oxidation membrane layer of Ti6Al4V alloy treated by hydrothermal synthesis. The results show that the samples treated with the micro-arc oxidation and hydrothermal synthesis shows excellent anti-hemolytsis, good anti-coagulant, anti-platelet adhesion and non-toxic, which has good biocompatibility.

Fatigue crack growth (FCG) experiments were carried out using extruded AZ31B magnesium alloy bar. The pre-crack compact tension (CT) specimens were oriented in three different directions with respect to the extrusion direction. The experimental results reveal that the specimen orientation has a significant influence on the FCG rate and crack path. The FGC rate of the T-L specimen is the highest while the L-T specimen shows the lowest value. Typical macroscopic Mode I crack is developed in the T-L and T-R specimens whereas a deviation from the Mode I crack path and branching occur in the L-T specimens. For the L-T specimens, a plateau of constant crack growth rate occurs at low stress intensity factor range ()^. Transgranular cracking is the major cracking mode. Slip induced cleavage dominates the transgranular cracking in the T-L and L-T specimens whereas both twin boundary cracking and slip induced cleavage exist in the T-R specimens. The FCG rate decreases with the increasing load frequency at.

MWCNTs doped polyaniline (PANI) were used as a precursor and the precursor added Fe salt was heated at 900℃ to obtain the Fe-containing catalyst FeNC. Cobalt salt was then added to the FeNC and the mixture was subjected to heat treatment at different temperatures to prepare the various composites FeCoNC. The structure, specific surface area, thermal stability and compositions of the catalysts FeCoNC were characterized by TEM, SEM, TGA and elemental analysis, respectively. The results show that the catalyst structure becomes uniform when the temperature is 500℃, and it appears sintering at the temperature higher than 500℃. The content of N increases first and then decreases with the increasing of temperature. The temperature has a little influence on the specific surface area of the catalysts. TGA suggests that the catalysts have good thermal stability in the air. ORR activity of the catalysts has been tested by CV and RDE techniques. Results show that the catalyst FeCoNC5 obtained by the heating treatment at 500℃ presents the highest electrocatalytic activity for ORR. The ORR current density at 2000r/min is 11.67 mA/mg@-0.3 V(vs SCE) in acidic solution and 9.83 mA/mg@-0.8 V(vs SCE) in alkaline solution, and the onset potential of ORR is 0.63 V(vs SCE) in acidic solution and -0.12 V(vs SCE) in alkaline solution.

a-Al₂O₃ powders with different shapes were prepared from the reaction of aluminum sulfate octadecahydrate and urea by hydrothermal pyrolysis method. The as-prepared products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of reaction time and additives such as PEG 2000 and AlF₃ on the morphologies of the products were evaluated. Without additives, spherical a-Al₂O₃ powders were obtained at 120 ^oC for 6 h followed by calcination at 1200 ^oC. When using PEG 2000 and AlF₃ as additives, fiber- and tabular-shaped a-Al₂O₃ powders were obtained under the same reaction conditions respectively. In addition, the reaction mechanisms of the formation of a-Al₂O₃ powders with different shapes were discussed.

The effect of corona discharging mode on the charge storage characteristics of fluorethylenepropylene (FEP) electret film are investigated in this paper. The FEP film was charged by a point-to-surface corona set-up with DC stable voltage, high-frequency impulse power and AC power supply. The charge storage characteristics of FEP electret films were investigated by means of measuring surface potentials and thermal stimulating discharge current. The experimental results are explained by the plasma sheath models based on gas discharge. It is concluded that the charge stability of FEP electrets are correlated to the corona discharging mode and to the corona polarity, however, the charge storage characteristics is only affected by corona polarity. The charge stability of negative polarity electrets is superior to that of the positive polarity electrets. The charge stability when charged with pulse corona is better than that with constant voltage corona, but the initial surface potentials are lesser. The polarity of electrets charged with AC corona is negative. According to the plasma sheath models, the composition and thickness of the plasma sheath will be different when FEP film is charged with different corona discharging mode, which is responsible for the different charge storage characteristics of electrets.

Ordered mesoporous carbon/silica hybrid materials were synthesized using the oligomer of urea-formaldehyde resin as carbon source, triple copolymer surfactant F127 as template and tetraethyl-orthosilicate (TEOS) as silica source via evaporation induced self-assembly (EISA)method. Through changing carbonization temperature, mesoporous carbon/silica hybrid samples with different BET surface areas and pore size distributions were obtained. The materials were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), Thermo Gravimetric Analyzer (TGA) and nitrogen adsorption-desorption analysis. The results showed that carbonization temperature would directly influence the pore structure. When the carbonization temperature is 850℃, the mesoporous carbon/silica hybrid material with perfect orderliness and narrow pore size distribution can be prepared.

A two-step method was used to synthesize a novel biodegradable polyurethane (PU) composed by L-lysine ethyl ester diisocyanate (LDI), poly (ε-caprolactone) diols (PCL-diol) and 1, 4: 3, 6-dianhydro-D-sorbitol (Isosorbide) as chain extender. 3D porous PU scaffolds were produced by a combined salt leaching-phase inverse technique. The surface structure, pore size, pore size distribution, pore interconnectivity and mechanical properties of the scaffolds were investigated. The bio-safety of PU was evaluated with cell proliferation of mouse ATDC5. Results show that micorpores and macropores distributed in the produced scaffolds with high porosity (more than 75%). The scaffolds that were prepared with addition of methanol and water have good tensile strength, with well interconnected pores. In addition, the CCK-8 expriment result displayed that the cells could survive and proliferate on PU scaffolds.

The structural evolution of the solid metallic composites subject to pulsed magnetic field has been investigated. The in situ nanometer Al₂O₃ particles reinforced 7055 aluminum alloy have been fabricated. The average size of endogenous particles is 42.3 nm. On the condition of 1 T, 2 T and 3 T the flake composite samples were processed by pulsed impact. In the treated samples the dislocation exhibits some specific characteristic as high density and diversity. It is analyzed that the magneto-plastic effect is the main reason that lowers the nucleation energy, accelerates the movement and increases the density of dislocations, facilitates the relief of massive internal stress. The dislocation density increases with the enhancement of magnetic induced intensity and when it equals to 3 T the maximum density is acquired. The morphology of dislocation displays as aligned, tangled, annular and spiral ones. The disordered atomic layer, deflected orientation, stacking fault and deformation twinning can also be seen. It is deduced that the dissociation of high density dislocation facilities the stacking fault and the overlap of stacking fault does the deformation twinning.

N-doped and oxygen-deficient titanium dioxide was synthesized by heating TiO₂ in NH₃ atmosphere, followed by the post-calcination in H₂ for different time. The physicochemical properties of the products were characterized by X-ray diffraction (XRD), N₂-sorption BET surface area, X-ray photoelectron spectroscopy (XPS), elemental analysis (EA), electron spin resonance (ESR), UV-vis diffuse reflectance spectrum (UV-vis DRS) and photoluminescence spectrum (PL). The photocatalytic activity of catalysts was determined by the degradation of gas-phase benzene under visible light (λ > 400 nm) irradiation. Effect of the H₂ heat-treatment on the photocatalytic performance of the as-prepared catalysts was investigated. The results show that the N-doped TiO₂ post-heated in H₂ atmosphere for 1 h exhibited the high photocatalytic activity. After photocatalytic oxidation for 5 h, the conversion rate and mineralization rate of benzene over the co-doped catalyst are up to 66.8% and 47.5%, respectively. The photocatalytic activity of the co-doped catalyst is much higher than that of the sums on N-doped TiO₂ and oxygen-deficient TiO₂. The enhanced photoactivity of the co-doped catalysts is related to a synergistic effect of N dopants and the oxygen vacancies in TiO₂ lattice.

In order to investigate the influence of stabilization treatment on microstructure and intergranular corrosion(IGC) resistance of Super304H austenitic heat-resistant steel, the microstructure including grain size, carbide distribution, type and amount of the samples after solution and stabilization treatment were characterized by optical microscope, scanning electron microscopy, electrolytic extraction method and X-ray diffraction. The intergranular corrosion degree was evaluated by oxalic acid electrolytic etching method and double loop electrochemical potentiokinetic reactivation tests. The results show that the grain grade of Super304H can be maintained between level 7 and 10 when quenched at 1150℃ for 15 minutes. Compared with the solution state, the amount of precipitated phases increased significantly after stabilization treatment. What is more, there were many M₂₃C₆ precipitates along grain boundaries when stabilized at 950℃, indicating that 950℃ was still at sensitizing temperature for Super304H. The Nb(C, N) quantity and IGC resistance increased with the increase of stabilization temperature, and its IGC resistance was superior to the solution state when stabilizing temperature reached 1100℃, where the Nb(C, N) precipitated most Meanwhile the 1100℃ was in the range of solution temperature for Super304H and was much higher than the stabilization temperature of conventional 1Cr18Ni9Ti stainless steel. It can be drawn that the delivery state heat treatment of Super304H plays the dual function of solution and stabilization.

A method for chemically attaching ultra-thin polymer films through the self-assembly of side chain polymers containing silane is provided in this article. Side chain trimethoxysilane functionaiized poly(phthalazinone ether ketone) (PPEK) was prepared and characterized by FTIR, ²⁹Si-NMR. The self-assembly behavior on the glass substrate of the obtained polymer films were investigated by measuring the water contact angle. The results show that the film formation can be completed in 1 h. The nano-scale morphologies of the films were investigated by atomic force microscopy (AFM). The friction coefficients of self-assembled polymer films against steel ball at a load of 100 mN are about 0.1 which is much lower than that for the bare glass substrate in the same experiment conditions (friction coefficient of bare glass is about 0.8).

In highly-dispersed and stable nano-CaCO₃ concentrates, the Sa10 hyperdispersant firmly adsorbed on the surface of CaCO₃ nanoparticles and a adsorptive layer formed. Nano-CaCO₃ concentrates improved the epoxy coating adhesion and the corrosion resistance. A adsorptive layer produced steric effect and hindered the nano-CaCO₃ particles to aggregate, while the solvatable layer transfered nano-CaCO₃ particles from the polarity shift to nonpolarity, increasing their compatibility with the epoxy resin, which ensured their uniformity and stable dispersion in the epoxy coatings. Thereby nano-CaCO₃ concentrates enhanced the physical shielding of the coatings, and improved the corrosion resistance.

The waterborne anti-corrosion paint was prepared by introducing the anti-corrosion pigment of conductive polyaniline (PANI) to the waterborne epoxy. Adding quantity (mass fraction) of PANI was 0, 0.2%, 0.4%, 0.6%, 0.8%, respectively. The dispersion and anti-corrosion effect were characterized with optical microscopic, electrochemical impedance spectroscopy (EIS), polarization curve analysis (LSV), X-ray diffraction (XRD), and salt spray test. The effects of the quantity of PANI on the anti-corrosion property of the waterborne anti-corrosion paint were investigated. The anodic and cathodic reaction can be insulated because of the suitable PANI adding, and the metal chelating substance and the shielding effect of oxygen are helpful. Metal oxide film formed intactly and the coating “flash” rust resistance and anti-corrosion effect can be improved. But when the adding amount of PANI was 0.8%, the effect of anti-corrosion decreased because the shielding the corrosion ions of the epoxy film decreased. The anti-corrosion property is the best when the quantity of PANI was 0.6%. The PANI can improve the quality of the oxidation film, and overcome the “flash rust” problem effectively.

Using low density polyethylene (PE), polymethyl methacrylate (PMMA) and hydrophobic SiO₂ as the raw materials, PE/hydrophobic SiO₂ and PMMA/hydrophobic SiO₂ composite coatings with superhydrophobicity were fabricated on the glass substrate by a simple one-step casting method. Several analysis equipments, such as contact angle meter, scanning electron microscope and X-ray photoelectron spectroscopy instrument, were used to characterize and analyse the wettability, morphology, and surface chemical properties of the as-prepared coatings, respectively. The results show that the static water contact angles of the two coatings are higher than 150° and the sliding angles are lower than 3.0°. It is also found that the micro-nano-binary structure, similar to lotus leaves, is essential for achieving an excellent superhydrophobic surface.

Effects of solution temperature on grain structure, grain boundary precipitation and creep behavior of GH4169G alloy have been investigated, and the creep mechanism and the reason for solution temperature influencing the creep of the alloy has been discussed. When the solution temperature is increased from 980℃ to 1020℃ the d phase precipitation at the grain boundaries markedly decreased, and the grain size largely increased, but the g″precipitation within the grain matrix is not influenced noticeably. In addition, the steady state creep rate at 650℃/700 MPa is greatly lowered, and the apparent activation energy is largely increased, and the creep rupture life is noticeably extended. It was determined through TEM observation that GH4169G alloy creeps mainly by twinning. The decreasing d phase precipitation helps to inhibit the creep through grain boundary slip, and the enlarged grain size naturally prohibits the twinning and hence mitigates the creep through grain deformation. As a result, the steady state creep rate of GH4169G alloy is decreased and the creep rupture life is extended.