Long-term aging at 650℃ for the austenitic heat-resistant steel 18Cr10NiNb was conducted till 10,000 h. Effect of aging time on microstructure was investigated by SEM and TEM, and the effects of Nb, C, and N content on equilibrium phases from 500℃ to 1400℃ in 18Cr10NiNb steel have been calculated by using Thermo-Calc software. The results show that Nb-rich MX phase particles precipitate in the grains and Cr-rich M23C6 carbide mainly precipitates at the grain boundaries. The main equilibrium phases in18Cr10NiNb steel at 500--1400℃ are MX,  M23C6 and  σ. The solution temperatures of  MX and M23C6 are about 1340℃ and 840℃, respectively. The amount of MX phase increases with increasing of C and Nb contents. The amount of  σ  phase decreases with increasing of C content. Adding 0.2%N in this the steel, MX phase contains N, Nb, Cr with a small amount of C, which is a complex carbon nitride and makes excellent strengthen effect. Cr2N phase appears as one of the equilibrium phases in the steel at the same time.

The effect of surface roughness of H13 steel on chromium coatings’ structure and properties was investigated by surface morphology and structure analysis, electrochemical impedance and polarization curve testing. The results show that when the electrodepositing time is less than 30 min, with the increase of the surface roughness of steel matrix, the grain size of chromium coatings decreases, and the grain accumulation becomes sparse; when the electrodepositing time is 30 min, the grain size and distribution of chromium coatings obtained under different surface roughness are same; when the time is more than 30 min, with the increase of the surface roughness, the grain size of chromium coatings increases obviously. When the surface roughness value Ra is less than 0.504 μm, the advantage growth surface of chromium grain is (200), and when Ra was 0.504 μm, the advantage growth surface of chromium grain changes to (211); the thickness and the microhardness of chromium coatings increase with the increase of electrodepositing time; with the reduce of surface roughness at a same electrodepositing time, the thickness of chromium coatings decrease, the microhardness increases, and the corrosion resistance of chromium coatings gradually increases.

The influences of MoS2 and graphite on the tribological properties of Ni--Cr based self--lubricating composites prepared by powder metallurgy were investigated. The results show that the micro--hardness of composites decreases obviously with the increase of content of MoS2. While the friction coefficient and wear rate of the composites don’t change evidently with increasing the content of MoS2 from 10% to 15% (mass fraction). The micro--hardness of composites reduces gradually with the rise of graphite amount, the friction coefficient of composites increases slightly at 400℃and 800℃. When the content of graphite is 10%, the friction coefficient of composite is lowest at room temperature. Addition of 5% MoS2 and 10% graphite, the friction coefficient of composites keeps 0.48--0.65 meaning the synergic lubricating effect between graphite and MoS2, and the wear rate is an order of magnitude higher than that of composites containing MoS2 alone or graphite alone.

The morphology and microstructure of the worn surface of carbon-carbon (C/C) composites, which were fabricated by CVD process and finally heat treated after 2300℃, were studied using scanning electron microscopy and transmission electron microscope. Most pyrolytic carbon around the fiber is high-textured pyrolytic, and there is a 1 μm thick low-textured pyrolytic intergrade layer between the fiber and the high-textured pyrolytic. The wear tests were simulating the normal landing of aircraft braking. The results showed that a compacted low-textured pyrolytic carbon friction film which is about 1 μm thick covered the worn surface after the wear tests.

The silica sols of particle size 20--100 nm were prepared using tetraethyl silicate as precursor. The porous silica antireflective coatings were prepared on the glass by the dip-coating method. The microstructure of sol particles with different particle size after aging and their influence on porous silica antireflective coating were investigated. Results show that the small silica colloid particles with size -20 nm reunit into large secondary particles during the aging process. The antireflective coating prepared of secondary particles has the desired loose structure and the peak transmittance of glass with the antireflective coating reaches 99.2% at 510 nm.

The thermal decomposition and subsequent crystallization process of Y sol after gelation were investigated by thermogravimetry--differential scanning calorimetry--mass spectrometry (TG--DSC--MS) coupling techniques, X-ray diffraction  (XRD) and Fourier transform infrared spectrometry (FTIR). The results show that Y gel loses lots of organic solvents and free water at 115℃. The hydroxyl condensation between gel molecules takes place slowly from 180℃ to 280℃. DSC curve of Y gel has two exothermic peaks in the range of 280--600℃, which are contributed to the transformation from carboxylate to subcarbonate at 380℃ and the formation of Y2O3 crystallite from decomposition products of subcarbonate at 440℃. Y gel completely transforms into α--Y2O3 at 600℃.

The effects of moisture, heat and UV light on the aging behave, the storage life and usage life of poly-p-phenylenebenzobisoxazole (PBO) fiber were investigated. It was found that the aging behaves of PBO fiber was susceptible to UV light. The cortex of the fiber was damaged severely during the 192 h accelerated UV light aging period, which led to significant reduction of tensile strength of fiber. The moisture had an evidently negative effect on the aging behaves of PBO fiber whether aging with UV light or not, and the effect was more obvious when exposed to UV light. The possible mechanism was the penetration of water molecules into the fiber‘s interior, which led to the formation of microfibril and the decline of fiber tensile strength. Increasing aging temperature can promote the penetration ability of water molecules, which speeded the decline of fiber tensile strength. The fibers aging in high humidity environments at a fixed temperature  degraded more quickly. PBO fiber had excellent stability in isolation from moisture and ultraviolet radiation.

The influences of hydrogen on microstructure and fatigue behaviors of electron beam welding TA15 alloys were investigated. No hydride formed when less than 0.105\% hydrogen were charged in TA15 welded joints. The substrates have better fatigue cracking resistance than that of the welded joint; and small amounts of charged hydrogen resulted in great drop of fatigue crack propagation life, because the exsited hydrogen reduced the toughness remarkably of the TA15 alloy in the welded joint and increased the fatigue crack growth rates. The hydrogen accumulated along the boundaries accelerated crack propagation along the martensite packets in the welded joints, resulting in the formation of “colony structure” on the fracture surface.

The effects of pulse period and saccharin additive on the microstructure of Ni films electrodeposited using pulse power from a conventional nickel sulphate bath have been investigated by SEM, XRD and TEM. The results show that, 1) an increase of pulse period during pulse electrodeposition favors to deposit a finer grained Ni film with increased homogeneity in the deposition orientations along <111>, <200> and <220>; 2) addition of saccharin during the pulse electrodeposition helps to significantly decrease the tensile growth stress, preventing Ni deposits from cracking; 3) an increase of pulse reverse period during pulse reverse electrodeposition causes a gradual evolution in the growth texture of Ni film from first appearance, subsequent disappearance and final appearance of  <200> dominant orientation.

Abstract: The X80 pipeline steel based on acicular ferrite was used in this article. Different heat treatment was done on X80 pipeline steel to got different microstructure such as poly ferrite and lath martensite . The HIC behavior of different microstructure of X80 steel was investigated by the hydrogen-induced cracking (HIC) susceptibility test and hydrogen permeation in H2S environment. The result indicates that the HIC susceptibility of different microstructure X80 steel is in the order of: water-quenching> air-cooling>original. Hydrogen trapping efficiency of steel is one of the main factors of HIC sensitive. The more the value of hydrogen flux J∞, hydrogen diffusion coefficient Doff, the fewer pipelines steel is prone to HIC.

Mg–3Sn–Mn alloy profiles have been successfully manufactured by the continuous rheo–forming equipment self–designed, and the effects of process conditions on the microstructures of the products were investigated. The results show that when the roll is at a certain speed and the casting temperature varies from 690^oC  to 750^oC with the decrease of casting temperature, the composition supercooling in front of solid–liquid interface and the solid fraction in the center increase, so, the width of columnar grain zone near the edge of the product increases, the equiaxed grain zone in the central position decreases, and the average diameter of grains in the equiaxed grain zone decreases. When casting temperature is kept constant and roll speed varies from 0.052 m·s⁻¹ to 0.087 m·s⁻¹, with the decrease of roll speed, the solid–liquid interface tends to be stable and the melt is subjected to the shear in the roller–shoe cavity for a long time, so, the width of columnar grain zone near the edge of the product decreases and the width of equiaxed grain zone in the central position increases. When the casting temperature is 690^oC  and roll speed is 0.052 m·s⁻¹, magnesium alloy profiles with cross–section of 5 mm×50 mm have been obtained, the surface and microstructure of the products are excellent, and the average grain size of the product is 27 μm.

Ag-IPMC was fabricated by using chemical deposition methods in this paper. The topography and chemical composition of the surface electrodes of Ag-IPMC were analyzed by scanning electron microscopy (SEM) and energy dispersive spectrum (EDS). And the DC-Actuating ability, moisture characteristic of different states and the performance of tensile output were tested. The results show that Ag deposits well both inside and outside of the exchange membrane. Ag-IPMC exhibits large deflection and significant tensile force for the stimulation of low voltage (less than 1.6 V). The relationship between various performance and excitation voltage shows that the best DC-excitation voltage for Ag--IPMC is 0.6--1.2 V.

The rapid solidification of undercooled Fe--Co alloy was investigated by combining cycle superheating and molten fluxing purification technology. The results show that metastable phase nucleated primarily only when the critical undercooling was achieved. After 3 h isothermal annealing in single phase γ region, metastable phase was transferred to stable phase completely. Finally, metastable phase in as--solidified microstructure of undercooled Fe--Co alloys can be described as a result of “competitive nucleation-- remelting-- extensive growth of  γ phase--incomplete solid state transformation”

Luminescent lanthanide materials BaMoO4:Eu3+ powders were prepared by chemical precipitation method using ammonium molybdate, barium nitrate and europium oxide as raw materials. Different BaMoO4:Eu3+ powders were prepared by controlling the pH value of solution, changing the sintering temperature and the doping concentration of Eu3+. The BaMoO4:Eu3+ powders were characterized by X-ray diffraction (XRD) and excitation-emission spectra. Experimental results show that a single phase of BaMoO4:Eu3+ can be obtained at solution pH~6, sintering temperature 1000℃ and 8% Eu3+ dopped concentration. The BaMoO4:Eu3+ powders have considerable luminescent intensity, and their excitations take on a double peak structure which locates at ultraviolet (394 nm) and visible blue light (465 nm). The emission is a line spectrum and the main peak located at visible red light (616 nm).

HZSM--5 zeolite was prepared by modification of NaZSM--5 zeolite with 0.3 mol/L hydrochloric acid. Photocatalysts of TiO2/NaZSM--5 and TiO2/HZSM--5 were prepared by dispersing TiO2 precursor onto the surface of NaZSM--5 and HZSM--5 zeolites using sol--gel method followed by calcination process, and the photocatalysts were characterized. The results show that the structure of the zeolite does not noticeably change after modification of NaZSM--5 by HCl, but its crystallinity reduces. Crystalline size of TiO2 decreases obviously after loading. The adsorption capacity of methyl orange and photocatalytic activity as well as surface area of the supported TiO2/ZSM--5 photocatalyst are significantly increased compared with that of bare TiO2. Further improvements of the properties were achieved after hydrochloric acid modification of the zeolite. Degradation rate of TiO2/HZSM--5 is 82.4% of the initial activity after the photocatalyst was reused for 4 times.

The composite membrane of TiO2/BC(bacterial cellulose) doped with rare earth elements was prepared by a sol-gel method using tetraisopropyl titanate as starting materials and BC as the support. Photocatalysis performances of the membrane were estimated by using methyl orange as a degradation agent. The results show that rare earth ions are incorporated into TiO2/BC membrane; the resulting titanium dioxide is anatase type. Compared with a pure TiO2/BC membrane, photocatalysis efficiency of the doped one is significantly enhanced. The degradation rate of methyl orange solution for the composite membrane doped with Ce4+ is higher than that of membrane doped with La3+. The optimal dosage of Ce4+ is 2 mmol/L, while the most suitable concentration of La3+ is 5 mmol/L. The degradation rate of methyl orange solution is above 70% after degradation for five times.

Microcrystalline silicon films were prepared using Ar diluted SiH4 gaseous mixture by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR--PECVD). The effects of the microwave power on deposition rate, crystallinity, grain size and the configuration of H existing in microcrystalline silicon films were investigated. The results show that the crystallinity increases and the concentration of hydrogen decreases monotonously with the increasing of the microwave power. But the deposition rate first increases monotonously, and then decreases. Optimized microwave power is 600 W for the highest deposition rate. <111> orientation is the only dominant crystal texture for films obtained with different power.

Mixing Pt--coated activated carbon with secondary activated carbon as adsorbent was used for hydrogen storage. Behaviors of hydrogen adsorption on Pt--supported activated carbon in the presence of a piezoelectric element were investigated. Hydrogen storage in activated carbons can be increased by secondary hydrogen spillover from a supported Pt catalyst. The piezoelectric element is able to autogenously generate charges in hydrogen pressure. The observed adsorption enhancements of NAC, Pt/NAC--1, Pt/NAC--2 and Pt/NAC--3 are 15\%, 36.5\%, 39.3\% and 43.9\%, respectively. The greater enhancement observed from hydrogen adsorption on Pt/NAC samples can be attributed to charges generated by PMN--PT facilitate dissociation of hydrogen molecules into hydrogen atoms. The easier accessibility of the atomic orbital might favor the electron transfer from the atomic hydrogen to charged carbon.

The gradient hydroxylfluorapatite composite coatings on Ti6Al4V substrate were deposited by radio frequency magnetron sputtering. XPS, XRD, IR and SEM were used to investigate the fluorine content, phase composition and surface morphology of coatings. The results show that the fluorine shows a gradient distribution. The Ca:P molar ratio decreases with the increase of fluorine content in the coating.The biological activity and stability of the gradient composite coatings were analysed in siulated body fluid(SBF). Results show that the new apatite growing on the HAF/YSZ gradient composite coatings is the bone-like apatite under SBF conditions, and fluoride can promote the development of apatite phase. Fluoride content in gradient distribution can effectively improve the anti-solubility and bonding stength. The biological activity and stability of HAF/YSZ are better than that of HA and single fluoride content coatings.