Advanced Materials Research Vol. 659

Abstract: RE nanophase composite material between the grain size 30nm and 100nm are prepared by the method of mechano-chemistry，in which the material’s adsorptive capacity to metal base is checked，and the nature of anti-friction as well as self-repairing effectiveness to the surface of abrasion is tested by four-ball friction wear testing machine. The results show that RE nanophase composite material prepared by the method of mechano-chemistry has a good adsorptive capacity to metal base，and the wear surface can be covered and repaired under dynamic condition；RE nanophase composite material used as anti-friction material is test and verified.

Abstract: This article is based on the magnesium alloy brush plating which is pretreated only by electro cleaning and not by activating. The process for brush plating mending of scratched surface of magnesium alloys parts which isn’t pretreated not only by electro cleaning and but also by activating is introduced．The merits of the technology that the plating is directly carried out after gluing the conductor colloid are discussed.

Abstract: In order to improve the density and mechanical properties of ceramic-lined composite steel pipes produced by Centrifugal Self-propagating High-temperature Synthesis. Composite steel pipes were prepared by the method of centrifugal-SHS on the basic of Al-Fe₂O₃ system. With the condition of adding 6% SiO₂ and 4% Na₂B₄O₇, the effect of different amount of nano-TiO₂ on the density and the mechanical properties of composite steel pipes was studied. By means of SEM analysis, XRD and mechanical tests, the results show that the ceramic layer consists of main crystal phase of α-Al₂O₃, with small amount phases of FeAl₂O₄, Al₂SiO₅ and B₂O₃. The surface of ceramic layer is smooth, without obvious crack and with good density. The shearing strength of the ceramic layer and the crushing strength of the composite pipe were 13.5 MPa under 8% (in mass) nano-TiO₂ and 525Mpa. The density of ceramic layer is up to 94.2% under 8% (in mass) nano-TiO₂.

Abstract: The traditional camouflage way is only used to camouflage the military objectives in the fixed background. As the seasons and temperature change, the background color is undergoing tremendous changes. To solve this problem, a new kind of intelligent camouflage coating was invented whose color changes with the temperature and blends with the background. Through orthogonal design and experiments, the composition of raw materials and mixture ratio has been determined. The physical and chemical performances of the coating such as drying time and color-changing temperature have been tested. The result shows that the coating has good coating effect, excellent mechanical and chemical performance which can meet the camouflage requirements of changing seasons.

Abstract: By means of entanglement and consolidation, fibers form stable web in spun-laced nonwovens, it initially conceived fibers entanglement structure and analyzed morphological changes in the stress state, the result showed that the elastic recovery property of spun-laced nonwovens could be adjusted through the deformation resilience of water mesh and the elastic fiber itself. Meanwhile the mathematical model demonstrated the most common "u-shaped" entanglement method between fibers,so fiber I slip from the fiber Π which met the equation T1 = T0×e μ θ. Under the same water jet pressure condition, larger static friction coefficient (μ) or fiber coated Angle (θ) equals better fiber entanglement, more stable structure and better elasticity. Combining the actual production with ideal mesh model, the size relations of horizontal and longitudinal extension deformation about Δ L and Δ L' was discussed. The results showed that the elastic recovery property of nonwovens could be improved through changing fibers arrangement of the fiber web.

Abstract: Based on the density functional theory, using the first-principles calculations method, the geometrical structure, electronic structure and optical properties of the ZnO(0001) surface were investigated. The calculated results show that a great change appears in the structure after the surface relaxation. The new energy levels were found in the band structure. The conductivity of the ZnO (0001) surface becomes stronger, showing the electrical properties of metal. On the other hand, imaginary part of the dielectric function of the ZnO(0001) surface also changes certainly. A new peak is observed in the low energy region. The results provide a theoretical basis for photoelectric device manufacturing and further development on the ZnO surface.

Abstract: Based on the first-principles calculations, we present a study for Mg-doped superlattices ZnO. We find that the volume of superlattices ZnO is reduced, while the band gap is extended. The dielectric function peaks of superlattices ZnO become smaller in the low-energy region. Interestingly, we further find Superlattices ZnO has great geometrical stability due to the electrostatic potential of the doped layer is smaller than that of pure ZnO. The results provide a theoretical basis for photoelectric device manufacturing.

Abstract: This paper discusses welding technique of quenching and tempering steel after final treatment, and raises a composite welding technique and its corresponding welding condition by combining SMAW and TIG welding. Finally, technical experiments and performance tests have been done on typical parts of high strength steel, the results are satisfactory and indicate that it may be used in aircraft maintenance.

Abstract: Fe-Al intermetallics coatings are prepared on an aluminum alloy ZL114A by laser cladding pure Fe and Al powders. The microstructure and hardness of the coatings are analyzed by using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and microhardness testing machines. The results show that a fine surface quality can be obtained under a suitable process parameter of laser. The laser cladding layers are mainly consisted of FeAl, FeAl3, Fe2Al5 and Fe3Al phases. The two cladding layers (60Fe-40Al, 90Fe-10Al) have high microhardness, which achieve HV520 and HV890.