In order to investigate the corrosion resistance of ocean platform steel E690 in sea water, the corrosion induced by oxygen-concentration cell of E690 steel in 3.5%NaCl with oxygen concentration within a range of 0.3 to 8 mg/L was investigated by means of electrochemical measurement techniques, scanning electron microscopy and Raman spectroscopy. The influence of the difference in dissolved oxygen, the ratio of cathode area to anode area and the corrosion product on the corrosion behavior of E690 steel was examined respectively. It was found that: when the ratio of cathode area to anode area was less than four (S_c/a≤4), the cathode and these ratios would be the main factor that influenced the oxygen-concentration cell corrosion; when S_c/a>4, the dissolved oxygen would be the main factor that influenced the oxygen-concentration cell corrosion; How the corrosion product influenced the oxygen-concentration cell corrosion depends on the dissloved oxygen. When the rusted metal under an oxygen-deficient condition, the rust layer would prevent the substrate from corrosion; when the rusted metal was immersed in an aerated condition, the corrosion product would participate in the cathodic reaction process, which would accelerate the anode dissolution and resulted in localized corrosion, such as pitting.

An alloy Mg₉₄Cu₄Y₂ with a large quantity of long-period stacking ordered (LPSO) phases bearing Cu and Y was designed and prepared in this paper. The microstructural transformations and the hydrogen absorption/desorption properties of the alloy were characterized during hydrogenation and dehydrogenation processes. The cast Mg₉₄Cu₄Y₂ alloy consists of phases such as Mg, Mg₂Cu and LPSOs with 18R or 14H type. The LPSOs decomposed at the first hydrogenation, and in situ formed highly even dispersed nanocomposite (MgH₂+MgCu₂+YH₃). The Mg/MgH₂ was the main reaction during the subsequent dehydrogenation cycles. The alloy exhibits excellent hydrogen absorption and desorption kinetics because the nano-sized and even dispersed Mg₂Cu and YH₂ catalyzed effectively the Mg/MgH₂ reactions.

High-quality and few-layered graphene was grown by chemical vapor deposition (CVD) on copper foils, which were pre-treated by etching with 25%HCl or 2 mol/L FeCl₃ and then electrochemical polishing in order to improve their surface smoothness. The surface morphology of the copper foils and the deposited graphene were characterized by means of Raman spectroscopy, XRD and SEM etc. The results showed that copper foils with desired surface smoothness would be acquired through etching with 2 mol/L FeCl₃ for 30 s and then electrochemical polishing for 60 s by applied voltage of 10 V; Films of layered graphene with less defects could be deposited on the pre-treated copper foils. The thickness of graphene films increased with the increasing time, however for a short deposition time the formed graphene films were discontinuous with poor quality. The monolayered high-quality graphene films could be prepared by depositing for 30 s, whilst the deposition time increased to 60 s a graphite film could form on the surface. In other word, it is necessary to control the deposition on time for growing the desired monolayered graphene films.

18CrNb is a kind of ferritic stainless steel and widely used as parts at the hot end of automobile exhaust system due to its good formability, high temperature strength and oxidation resistance. In this paper, the oxidation of 18CrNb steel in a temperature ranging from 700℃ to 1000℃ was studied through continuous oxidation behavior test. The oxide scale was then characterized by XRD, SEM and EDS, while the oxidation dynamic curve of this steel was plotted based on the weight-gain data after oxidation. The results indicate that 18CrNb steel has excellent oxidation resistance at temperatures lower than 900℃ due to the formation of continuous and dense Cr-rich oxide scale. When the temperature rises up to 950℃, the oxide scale turn to be complex, of which the outer portion composed of Cr-rich Cr-Mn oxide, Mn-rich Mn-Cr oxide, Fe oxide and pure iron oxide; the inner portion composed of Fe-rich Fe/Cr oxide; thereby the scale became loose leading to breakaway oxidation. According to the results of this work, 18CrNb is not suitable for application at temperatures above 950℃.

Lanthanum nitrate conversion coating was prepared on a hot-dip Galfan steel by dipping in a passivation solution of La(NO₃)₃. The surface morphology, chemical composition and structure of the coating were characterized by scanning electron microscopy (SEM) with X-ray energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). The corrosion resistance of the conversion film coated steel was assessed by neutral salt spray tests (NSS), electrochemical polarization curve and electrochemical impedance spectroscopy (EIS). The results showed that the conversion coating was not uniform, which had grown preferentially on grain- and phase-boundaries as well as other active sites. The thickness of the coating increased, while cracks in the coating expanded gradually with the increasing dipping-time. The coating spall off after dipping for more than 30 min, and therewith the protective performance of the coating degraded. In comparison with the blank Galfan steel, the corrosion rate of the conversion film coated Galfan steel lowered down significantly.

Bare and high-energy (20 MeV) W⁶⁺ pre-implanted polycrystalline tungsten samples were irradiated with low-energy H-ions. The effect of H-ions energy (20-520 eV) and irradiation temperature (673-1073 K) on the microstructure evolution of these samples was characterized by means of non-destructive conductive atomic force microscopy and scanning electron microscopy in terms of the surface morphology and distribution of irradiation induced defects. The results show that a large number of nanometer-sized protuberances were formed on the irradiated tungsten samples, but the irradiation induced damage for the pre-implanted ones was slighter than the bare ones. For pre-implanted samples, low-energy H ions irradiation results in a random distribution of nanometer-sized protuberances, indicating that high-energy W⁶⁺ implantation can release the surface damage of tungsten induced by low-energy H ions to some extent. It also showed that the release effect was decreased when the irradiation temperature was higher than 1073 K.

Mesoporous nanocomposite of Co-doped hydroxyl-Zr -pillared titanate (CZPT) was prepared via an exfoliation-restacking route, and the pre-exfoliated layered titanate was reassembled in an aqueous solution containing hydroxyl-Zr oligocations and Co ions. The influence of the doping Co cations on the preparation and catalytic activity of Zr-pillared titanate (abbreviated as ZPT) composites was investigated. The prepared CZPT was characterized by powder X-ray diffraction, scanning electron microscope, transmission electron microscopy, UV-Vis spectra and porosity measurements. XRD and N₂ absorption results suggested that the ZPT doped with 5% Co (mass fraction) had bigger pore diameter and specific area. The presence of 5% Co could effectively suppress the annihilation of the photogenerated hole-electron pairs, and correspondingly the absorption wavelength exhibits obviously red-shift. The degradation of rhodamine B (RhB) under ultraviolet and visible radiation shows that the as-prepared nanocomposite exhibits higher photocatalytic activities than that of layered titanate alone. The enhanced photocatalytic activity of the as-prepared nanocomposite CZPT-5 for the degradation of RhB under visible irradiation may be attributed to the coupling interaction between cations of the host and the Co containing guest.

The 4343 Al-Si alloy is the most widely used brazing filler metal for the multi-layer aluminum clad sheets, which act as radiator fin for aluminum heat exchanger. In this paper, 0-1.0%(mass fraction) Cu or Sn was added to 4343 alloy in order to develop a new brazing filler metal with lower melting point and better collapse resistance. The results show that with the increase of Cu or Sn, the solidus and liquidus of the alloys decrease gradually, and when the Cu or Sn content is increased to 1.0%, the solidus and liquidus will be reduced by 10-15℃ respectively. With the increase of Cu ro Sn content, the Cu bearing intermetallic phases or the Sn particles increase in the cast alloy; after hot extrusion the Cu bearing intermetallic phases dissolve and Sn particles can induce the dissolution of Fe-Si bearing intermetallic phases; the tensile strength increases gradually while the elongations decrease a little. The results of trial brazing show that the addition of Cu or Sn will decrease the brazing temperature, particularly, the brazing temperature can be reduced by more than 15℃ for the filler alloys with 1.0% of Cu or Sn.

The effect of different Fe contents (0.03%, 0.17%, 0.24%) on the mechanical properties of Ti-6Al-4V ELI (TC4 ELI) alloy was studied. The microstructures were characterize by using EBSD, and the tensile properties, fracture toughness and fatigue crack growth rates (da/dN), creep properties of TC4 ELI with three Fe contents were compared and analyzed. The results showed that with the increase of Fe contents, Fe has no apparent influence on fracture toughness, however, tensile strength of the alloy was improved. The da/dN of the three TC4 ELI alloys were found to be almost identical at room temperature and 200℃, however da/dN was found to be marginally faster as Fe contents increased at 400℃. Within the range of 250~350℃, Fe improved creep resistance, while from 350℃ to 400℃, Fe had opposite effect. Fe atom was mainly enriched in β phase. And the tensile strength was improved with the increase of Fe contents due to the solid solution strengthening effect. Because of the high diffusing rates of Fe atom under the condition of 400℃, the movement of matrix atoms and interfaces were accelerated. So that, the resistance to dislocation motion in crack tip plastic zone was reduced, which led to higher da/dN. Under the condition of 350-400℃, Fe could improve the creep rate by speeding up the process of dislocation climbing, but the reinforcement is more important below 350℃ because of the weak diffusion.

A novel composite material CPAIL@TiO₂, which exhibits high photocatalytic activity, was prepared by a sol-gel method using raw materials of tetrabutoxytitanium and cross-linked poly(amphoteric ionic liquid) (CPAIL). The prepared CPAIL@TiO₂ was characterized by XRD, SEM, EDS, TEM, FT-IR, TGA and XPS. The results show that the mesoporous nanospheres of composite material CPAIL@TiO₂ contains ca 40% TiO₂, which is characterized as anatase. There existed chemical bands of C–O–Ti in the composite material. The CPAIL@TiO₂ shows a good photocatalytic activity and cycle performance. The photocatalytic degradation efficiencies of the CPAIL@TiO₂ could reach 97% and 55% of those of pure TiO₂ for solutions of methyl orange (MO) and methylene blue (MB) respectively. In general, the above superiority of the composite material CPAIL@TiO₂ demonstrates better prospects for applications in the field of environmental protection.

The magnetic composites with low density of cenospheres-barium ferrite were prepared by a sol-gel self-propagating combustion technology. The morphology, structure, electromagnetic properties and microwave absorption properties of the composite powders were characterized by the scanning electron microscope, thermogravimetry-differential scanning calorimetry, X-ray diffraction, vibrating sample magnetometer and vector network analyzer. The results show that cenospheres were covered with barium ferrite coating of ca 5 nm to 15 nm in thickness. The size of barium ferrite coated particles is less than 60 nm. In addition, it is found that the composites are composed of barium ferrite, hematite, minor mullite and quartz, and the magnetic properties of the composite material could be enhanced with the increasing mass ratio of barium ferrite to cenospheres. Furthermore, the samples exhibit better dielectric loss and magnetic loss properties within a frequency range from 2 GHz to 18 GHz. The maximum reflection loss of the composite material of 1.5 mm in thickness reaches -29.2 dB at 14.2 GHz and the bandwidth for reflection loss of -10 dB is 4.5 GHz.