Four basic electrodes were designed by the method of transition alloying elements through coating. The influence of coating alloying elements on microstructure and properties of basic electrode welded joints were studied by using welding test, metallurgical analysis, mechanical property testing and fracture scanning tests. The results showed that with the increase of alloying elements, the changes of four kinds of weld microstructure is small and mainly composed of tempered sorbite and lath martensite, and accompanied by a small amount of residual austenite and quadratic precipitated phase, but the microstructure gradually changed from lath to thin strips, and staggered density increases. What's more, the strength of four welded joints has a little changed, but the impact of toughness has a greatly improved and the fracture dimples became many and deep. Last, the effect of coating alloying elements on welds microstructure and properties is a complementary and mutual restraint process, and the content of alloying element in No.3 electrode makes the basic electrode weld strength and toughness to achieve a better matched.

The influence of solution treatment on the quench sensitivity of Al-7.9Zn-2.5Mg-1.0Cu alloy during quenching was investigated by optical microscopy(OM), differential scanning calorimetry(DSC), scanning electron microscopy(SEM), transmission electron microscopy(TEM) and end quenching-hardness measurement. The results show that the hardness of different solution treatment samples decreases with the distance from quenching end increase. Moreover, the quench sensitivity of 450 ℃/8 h+475 ℃/2 h treatment sample is higher than that of samples of 475 ℃/2 h treatment. The quenched depth is about 65mm, while that of samples of 475 ℃/2 h treatment is more than 100mm. There is few effects of solution treatment on the degree of supersaturation, While comparing to 475 ℃/2 h single-solution sample, the number of recrystallization grains and subgrains of 450 ℃/8 h+475 ℃/2 h double-solution sample increase, which facilitated separation of more coarse η equilibrium particles in the samples of, and lead to higher quench sensitivity.

The CZTS thin films were fabricated by sulfurization of sputtered CZT precursors, vulcanized at 350, 400, 450, 500 and 550 ℃ respectively, characterized through the analyses of XRD, XRF, SEM and Raman spectrum, and the influences of sulfurization temperature on the compositional and structural properties of CZTS thin films were investigated. The results show that the sulfurization process did not occur in the films sulfurized at the temperature of less than 400 ℃. Instead, the main change in the films was the inter-diffusion of the alloying elements, accompanying with the appearance of tiny amount of Sn₃S₄ and ZnS. CZTS appeared in films sulfurized at 450 ℃ while a quantity of SnS also existed in the films. For films sulfurized at 500 ℃, principal phase is CZTS with grain size of almost 2 μm, yet with a high surface roughness at the same time. For films sulfurized at 550 ℃, CZTS thin films with grain size around 2 μm and smooth surface were obtained.

The chemical modification of multi-walled carbon nanotubes (MWNTs) was carried out with hexamethylene diamine (HMD), and the carbon nanotubes/carbon fibers (CF)/epoxy resin (EP) composites were prepared. This paper was aim to study the anti-aging properties and failure mechanisms of the CF/MWNTs-EP three-phase composites through detecting mechanical properties and morphology of fracture surface. The addition of MWNTs-NH₂ in the composites increased the salt spray resistance properties, thermal-oxidative aging resistance and damp heat aging resistance under the given aging conditions. Performance of the interfaces between fibers and the matrix resin got improved due to the adding of MWNTs-NH₂. Meanwhile, MWNTs-NH₂ could promote the curing of the epoxy resin and reduce porosity, resulting in significantly improving aging properties. As 1.0% MWNTs-NH₂ was added, the salt spray resistance of three-phase composite material in the salt spray times of 72 h and 168 h was improved by 61.8% and 67.5% respectively compared with CF/EP composite. The thermal-oxidative aging resistance of the three-phase composite materials in the thermal-oxidative aging times of 48 h, 96 h and 168h was improved by 43.5%, 48.5% and 41.7% respectively compared with that of CF/EP composites. In addition, the damp heat aging resistance of three-phase composite materials in the different damp heat aging of 72 h and 168h was improved by 52.8% and 60.0% respectively compared with that of CF/EP composite.

Dependence of coefficients of performance (COP) on various parameters of metal hydride automobile air-conditioning system is investigated. The results show that working temperature, flat plateau and hysteresis influence COP values. With increase of working temperature of hot spot alloy, COP of air-conditioning system firstly increases and then decreases. There is a suitable working temperature range of hot spot alloy range to obtain a higher COP. Higher working temperature of cold spot alloy, flatter plateau and smaller hysteresis, are also beneficial to reaching a higher COP.

ABSTRUCT The microstructure and property of 80mm thick 7150-T7751 aluminum alloy plate in different layers were investigated by tensile properties, optical microscopy(OM), composition analysis, scanning electron microscopy(SEM), electron back-scattering diffraction(EBSD) and texture tests. The results show that the microstructure and tensile property in different layers of 7150-T7751 aluminum alloy of 80mm thick are inhomogeneous and the inhomogeneity has no correlation with macrosegregstion of the composition. The tensile property show obvious anisotropy in the plate and the characteristics of anisotropy at different layers are different. The strength of the rolling direction at the center is higher than that of the transverse direction. The strength of the rolling direction at the quarter is the smallest and is lower than that of the transverse direction. The texture of solution and ageing plate is stronger although the rolling deformation degree is smaller at the center of plate. The higher strength can be obtained along the long direction of coarse grain when the coarse and long recrystallization grains and the fine equiaxed grains are matching in 7150-T7751 aluminium alloy plate.

A series of poly(ether ester) thermoplastic elastomer, based on poly (tetramethylene ether) glycol (PTMG) and poly(butylene terephthalate)(PBT) have been prepared by molten polycondensation. Structure and property characteristics of materials were characterized by means of NMR, FTIR, SEM, DSC, DMA, TGA and mechanical testing. The influence of different molar ratios of 1, 4-butanediol(BDO)∶Dimethyl terephthalate(DMT)(2.5∶1~1∶1) with constant proportion?of?soft block on the poly(ether ester)’s properties was mainly investigated. It was observed that: the crystallization of the polyester hard block PBT are reinforced with the increase of BDO∶DMT molar ratio, the layered regulatory crystal and interface morphology were promoted by the exaltation of micro-phase separation. The crystallinity , storage modulus, tanδ as wells as the mechanical properties increase with the increase of BDO∶DMT molar ratio. However when BDO∶DMT were more than 1.6∶1, residual low molecular BDO crystallized between phase interface and PBT layered crystals greatly impeded micro-phase separation, and the phase interface area were easily debonding or slipping, therefore, the crystallinity , storage modulus , tanδand mechanical properties of materials reduced gradually.

Iron ore tailings are used as raw materials to prepare autoclaved aerated concrete (AAC). The effects of fineness and content of iron ore tailings on the properties of AAC were investigated. The results show: as the fineness of iron ore tailings decreases, the mobility of slurry increases, a formation of lot of fine and even bubbles decrease the density of bulks; however, too fine tailings lowers mobility of slurry and a lot of bubbles crack while pouring, which increases density. The decrease of fineness of tailings leads to increase of the hydration reaction rate, generate more hydration products, so compressive strength of bulks increases. But, too fine tailings results in too fine residual of raw material, which is bad to form good pore structure and lowers the strength. High content tailings can fill completely space among hydration products and increase the bulk density. Increase of tailings content increases the amount of tobermorite, and changes the shape of tobermorite from needle-like to short-fiber-like, intersection of which forms network structure and increases the strength. However, too high content of tailings makes the connection of products and the network structure loose, the amount of tobermorite decrease, which result in decrease of the compressive strength.

Thermotropic liquid crystal polymer (TLCP) and phenol formaldehyde (PF) firstly were prepared through melting extrusion methods, then Graphene oxide (GO) which synthesized by a modified Hummers method, GO which modified by silane coupling agent KH550 and KH560 were added to the matrix TLCP) and PF, respectively, the GO/TLCP/PF hybrid composites were prepared. The thermal properties, mechanical properties, dynamic mechanical thermal analysis, creep and stress relaxation behavior of GO/TLCP/PF hybrid composites were investigated. The results show that the properties of GO/TLCP/PF hybrid composites were obviously improved. The impact strength and the storage modulus of GO/TLCP/PF hybrid composites, GO modified by silane coupling agent KH560, are increased by 25.6% and 28.1%, respectively. Creep and stress relaxation performance has also been improved.

The hot compression deformation behavior of the spray-formed M4 high speed steel was investigated on thermal simulator at the temperature of 950 ℃-1150 ℃, strain rate of 0.01 s^-1-10 s^-1 and total strain of 0.7. The hot deformation constitutive equation for this alloy was obtained as well as the hot deformation activation energy. And the microstructures of the as-deposited alloy at different states were characterized presently. It is shown that the microstructure of the as-deposited M4 high speed steel possesses much finer and uniform-distributed grains without macrosegregation than the as-cast M4 high speed steel. The dynamic recrystallization are prominently performed during the deformation and the flow stresses are greatly affected by the temperature and strain rate. The morphology and distribution of the carbides are obviously influenced by the deformation temperature.

In this paper, the gelatin/PVA biodegradable composite films were prepared with gelatin(Gel) and poly(vinyl alcohol)(PVA) by a solvent casting method, which were modified by cross-linking with glyoxal. The chemical structure of the Gel/PVA composite films before and after glyoxal cross linking was characterized by Fourier Transform Infrared Spectroscopy(FTIR), X-ray diffraction(XRD), differential scanning calorimetr (DSC), and thermogravimetry analysis(TG). The effects of crosslinking agent concentration on mechanical properties and solubility the Gel/PVA composite films were investigated. The results show that with increasing the amount of glyxoal, the tensile strength of the Gel/PVA composite films increased and then decreased, while the elongation at break and solubility of the composite films decreased gradually. The melting temperature and thermal stability of the Gel/PVA composite films were improved by glyoxal crosslinking. The glyxoal crosslinking has an obvious effect on the hydrogen bonding between molecules and chemical structure of Gel/PVA composite films.

Oxidized celluloses with carboxylate content of 0.8mmol/g on C-6 position were prepared by oxidizing the bleached eucalyptus pulp with 2, 2, 6, 6-tetramethylpiperidinyl-1-oxyl (TEMPO) and NaClO in water at 60 ℃ and pH 6.8, with NaClO₂ as the primary oxidant and then sheared into nano-crystalline cellulose (NCC) via ultra-high pressure homogenizer. Using cadmium chloride and sodium sulfide as precursors and NCC as substrate material, NCC/CdS opto-electrical nano-composites were successfully synthesized by a sonochemical method. The structure and properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transformed infrared (FT-IR) and photoelectric experiments. Results show that a lot of nano-CdS particles are evenly compounded with the NCC and its crystal size is about 7.3nm according to XRD. A film with high transmittance of more than 60% in visible light region was prepared from the NCC/CdS nano-composites. The photocurrent of NCC/CdS nano-composites is 13.5 μA, which is 6 times of the microcrystalline cellulose (MCC)/ CdS nano-composites.

Fe-Ni alloy coatings were prepared on the surface of mild steel by means of thermal diffusion, using nano-NiO powder as the source of Ni element. The effects of treatment temperature on surface state, structure and corrosion resistance of the Fe-Ni alloy coatings were investigated. The result shows that: when the treatment temperature was higher than 800 ℃, 20-25 μm Fe-Ni alloy coatings formed and Ni content (atomic fraction) were higher than 25% on the surface, the coating and the substrate was integrated to metallurgy structure. When the treatment temperature was higher than 900 ℃, Fe-Ni alloy structure became single α-Fe solid solution phase. The corrosion resistance of Fe-Ni alloy coatings increased with the treatment temperature from 700 to 1000 ℃. In contrast with mild steel in 3.5%NaCl solution, the Fe-Ni alloy coatings have more positive corrosion potential, much lower corrosion current density. The electrochemical impedance of Fe-Ni alloy coatings was also bigger than that of mild steel in 3.5%NaCl solution.

Nanocomposite epoxy coatings were prepared with Zr nanoparticles and resin. Zr nanoparticles was characterized using transmission electron microscopy (TEM) and X-ray diffraction spectroscopy (XRD). Measurements of mechanical properties of coatings with different loading of nanoparticles were carried out. Effects of Zr nanoparticles on the coating corrosion resistance were investigated using salt spray tests and electrochemical impedance spectroscopy (EIS). Results show that the diffusion coefficient of water in the coating with 10% Zr nanoparticles is 6.0×10^-6 cm²/s, and decreases an order of magnitude than that of other coatings. Zr nanoparticles with appropriate loading dispersed homogeously in the coatings play a role of physical barrier, thus the corrosion resistance of the coatings is improved.

In situ aluminum alloy matrix composites were processed by Friction Stir Processing. The microstructure and tensile properties of composites after different passes FSP were analyzed. The results show that, in the stir zone, the composites have finer grains and large clustering of particles have been broken up, which leads to a more homogeneous particles distribution. The casting defects produced in preparation process are also eliminated during FSP. The grain size changes from 45 μm to 2 μm. Comparing to 1-pass FSP, after 4-pass FSP, composites have more homogeneous microstructure. Due to the changes of microstructure and the elimination of defects, the tensile properties of stir zone have been significantly improved. The tensile strength of the composite is 1.3 times of base material and the elongation is 8 times of base material.

The diamond films were successfully fabricated on low-alloy steel substrate with Cr+Cu-Diamond interlayer deposited by magnetron sputtering for Cr/Cu and composite electroplating for Cu-diamond. The interfacial characteristics were investigated by indentation test and the surface morphology, phase structure and residual stress were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy. The results show that the Cr layer on low-alloy substrate prevents Fe from diffusing to Cu/diamond interface effectively by converting into (Cr, Fe)₃C₂ and (Cr, Fe)₇C₃ in CVD diamond growth. Low residual stress detected in diamond film can be attributed to the chromium-iron carbide and copper layer for relieve of phase transformation and thermal stress during CVD cooling process. Concentric cracks with no delaminate area on the periphery of the indentation in 441N load shows good adhesion between diamond and low-alloy steel substrate.

In this paper, the AZ31 magnesium alloy sheets which have distinct textures and different grain sizes were prepared through different rolling processes, the effects of technological parameters on formability of the magnesium alloy were studied through erichsen test at room temperature. The result show that the strain hardening in the rolling direction of the magnesium sheets which produced in the deformation process can be improvement by increasing the grain size and reducing the basal texture, meanwhile, the elongation and room temperature formability of the magnesium alloy sheets are also improved. The grain size of the magnesium alloy which was prepared by cross shear rolling (the rolling and annealing temperature is 400 ℃, the different rolling speed ratio is 1.5) increases to 20 μm, while the maximum of the (0002) pole figure is only 2, the IE value which is obtained by erichsen experiment is 5.71, the room temperature formability of the magnesium alloy increase significantly.

The Cu-Cu₂O coating was prepared by Cold Spray Technology, polarization behavior of the coating in seawater was investigated and the corresponding mathematical model was established. The esults show that Cu₂O promoted localized corrosion in the beginning and with the increase of the soaking time local corrosion products can promote film-forming. The corrosion of coating was controlled by CuCl₂^- diffusion in a static environment. Cl^- promoted the corrosion of coating and hindered film-forming. Cl - CuCl complex is first order reaction of the Cl - concentration. H⁺ was produced in the transform process from CuCl to Cu₂O, which reduced the pH value of solution nearby electrode surface and affected the forming and durability of the oxide film adversely. Existence of buffer solution can increase break potential of oxide film effectively. Mathematical model was established based on reaction course coincides with experimental results well.

Activated carbon from ligin was prepared by phosphate activation in this paper. The effects of 4 factors such as impregnation ratio, phosphate concentration, activation temperature and activation time on the adsorption properties of activated carbons and yield were investigaited. The results show activated carbon iodine adsorption value and methylene blue adsorption value increase at first and then decrease with the increase of impregnation ratio, phosphate concentration, activation temperature and activation time. The four factors contribute to the formation of more micropores, and improve activated carbon adsorption properties. However exceeding a certain level, the internal part of the micropores of the activated carbon between the bore wall thin even burn, resulting in the microporous expanded to the hole and even largeholes. At the same time, phosphate can react with the carbon atoms of a hole wall forming the microporous structure, causing the carbon material excessive ablation, the large pore size, so that the adsorption properties of the activated carbon is reduced. The equilibrium adsorption datum match Freundlich model well. The adsorptions of phenol by activated carbon resin are in accordance with Freundlich isotherm model, and the adsorption kinetics data fit well with the Lagergren pseudo-second order rate equation.