Advanced Materials Research Vol. 460

Abstract: Chromium-free conversion coatings were generated to replace chromate chemical process by electrolysis treatment LY12 aluminum alloy in zirconate solution. Film thickness, dropping test, the adhesion between aluminum and paint film were tested for single-factor experiments and orthogonal to seek better electrolysis process. The paint adhesion is the first grade for electrochemical conversion solution containing complexing agents, or it is the second grade without complexing agents. When DNS complexing agent is 2 ~ 5g/L, film corrosion resistance rises with the increasing content of complexing agent. If voltage is too low, corrosion resistance of conversion coating is poor; voltage is too high, the films form powders. Better formulations for zirconate conversion coating are: 5g/L DNS complexing agent, 10V voltage, treatment temperature is 40°C. Electrochemical conversion coating is thinner than chemical conversion, but the corrosion resistance is better because the electrochemical conversion coatings are smoother and compacter than the chemical conversion coating. The paint films on electrochemical conversion coating are smoother than the chemical one. Two kinds of conversion coatings have very good adhesion with paint film up to the first level. Electrochemical conversion coatings thickness is 2.5 μm, bubble time of NaOH-glycerine solution on them is up to 92s.

Abstract: The silane films are fabricated by dipping cast aluminum alloy in silane solution, then curing films. The corrosion resistance of single silane film, composite silane film is compared with phosphating film through acid dropping test, salt water immersion test and electrochemical impedance test (EIS), the results shows that the silane films are obviously superior to the phosphating films in terms of the corrosion resistance of acid solution and neutral salt solution, particularly the corrosion resistance of composite silane films is much better than sigle silane films; corrosion polarization curves show that the corrosion tendency of KH550+KH567 composite silane film is minimum, corrosion rate is yet minimal, corrosion process of this silane films is controled by diffusion step. The corrosion process of uncoated aluminum substrate, KH550 silane films, phosphating films are controlled by electrochemical step. The impedance of phosphate films are lower than the silane films. Appropriate silane treatment can effectively improve adhesion between the coating and the Al substrate. The adhesion between silane film and paint film is firmer than the phosphate film, so silane film is an excellent replacement to phosphate film for painting pre-treatment.

Abstract: Silane coupling agent is gradually concerns as a substitute for phosphate pre-treatment of painting. Ten kinds of silane solution such as the KH-450, KH-460, KH-470, KH-550, KH-560, KH-567, KH-578, 5501, 9810, BTSE were chosen as research objects in this paper. Corrosion resistance and adhesion of film were studied after silane treatment on A3 steel surface by copper sulfate drop test, alternate immersion in salt solution and adhesion experiments. These silane films were compared with uncoated A3 steel specimens. The results show that: silane treatment can improve the corrosion resistance of A3 steel in acid solution. KH-560, KH-5501 and KH-470 were ranked the top three in the corrosion resistance. KH-550, KH-560, KH-567 were fourth, fifth and sixth, respectively. Silane treatment can improve the corrosion resistance of A3 steel in neutral salt solution. KH-460, KH-560 and KH-567 have the best salt water corrosion resistance. KH-560 has better adhesion with paint film, following by KH-550 and KH460. When using ethanol and water as the hydrolysis solvent of silane, KH-450, KH-460, KH-470, KH-550, KH-560, KH-567, KH-578, 5501 have the better stability, but stability of 9810, BTSE are poor.

Abstract: A tracking controller based on RBF (Radial Basis Function) neural networks compensating in vision based autonomous vehicles is designed in this paper. One input of the RBF compensating model are the lateral offset which measured by the vision system as the distance between the road centerline and the center of the vehicle a certain distance before. Another input is the steering angle which was collected when the vehicle was driving by a human testing driver. The controller is finally made by linearly fitting the parameter of the RBF neural networks. The stability is proven by composite Lyapunov functions. The robustness of the controlled system is theoretically investigated with respect to speed variations and uncertain vehicle physical parameters. Several simulations are made on a sedan vehicle to prove the effectiveness of this controller when perform path tracking on roads with an uncertain curvature.

Abstract: The interaction among Cerium, Arsenic and Iron at high temperature in a pressure-tight reactor were studied by means of electron probe microanalysis, optical microscopy and X-ray diffraction to understand what compounds could be developed and how about their stability chemically should be. The result shows that the binary compound CeAs is the main product on condition that the atomic ratio of Cerium to Arsenic is 2:1. There are some Fe2Ce, Ce4As3 and Fe17Ce2 compounds developed meanwhile. The amount of Fe17Ce2 phase by the base of steel increased with time prolonging at high temperature

Abstract: Based on the analysis of the interaction of the nano-particles and the matrix interface layer, assuming when the elastic properties of the interface layer change the total energy difference arising from it transfer to the nanoparticle surface, the effective elastic moduli of the nanoparticles with interface equilibrium can be obtained. Using the traditional continuum micromechanics approach, the effective modulus tensor and effective elastic moduli of spherical nanoparticles reinforced polymer matrix composite considering the interface layer effects of nanoparticles – matrix is predicted, and the effects of the volume fraction (mass fraction), the average particle size of nanoparticles and interface layer structural parameters and elastic properties to effective elastic moduli of composite materials is discussed

Abstract: In this paper, nonlinear dynamic buckling of FGM shallow conical shells under the action of triangular pulse impact loads are investigated. The nonlinear dynamic governing equation of symmetrically FGM shallow conical shells is built. Using Galerkin method, the nonlinear dynamic governing equation is solved, and the nonlinear dynamic response equation of symmetrically FGM shallow conical shells is obtained. The Runge-Kutta method is introduced to numerically solve the nonlinear dynamic response equation and the impact response curve is achieved. Budiansky-Roth motion criterion expressed by the displacement of the peak of the shell is employed to determine the critical impact buckling load. The influences of geometric parameters and gradient constants on impact buckling are discussed as well.

Abstract: The RBF network was applied in the rotor system to realize the fault diagnosis aiming the mapping complexity between fault symptoms and fault patterns. It can overcome the problems of low learning rates of convergence and falling easily into part minimums in BP algorithm, and improve the precision of diagnosis. The normalized values of seven frequency ranges in amplitude spectrum were used as the fault characteristic quantity, the RBF network was trained to diagnose the faults of rotor system. The results show that RBF neural network is a valid method of diagnosis of mechanical failure.

Abstract: BaV2O6 photocatalyst was prepared by liquid-phase deposition method in paper and different calcination temperature effecting photocatalytic activity were investigated. X-ray diffraction (XRD) has been employed to characterize the as-synthesized materials. The photocatalytic activity was evaluated by degradation of Methy lorange(MO) under the UV-light.It was found that as-prepared BaV2O6 with molar ratio of V5+ to Ba3+ be 2:1, pH=7 and calcinated under 500°C for 4h exhibits higher activity than any other calcination temperature. The highest degragation rate was about 65% or so in 100min.

Abstract: This paper illustrates China Work Safety Early Warning Information System on the basis of some major and significantly major accidents and special Wenzhou D-prefaced trains accident. Structure and functions of China Work Safety Early Warning Information System are shown. Weaknesses of China Work Safety Early Warning Information System are also pointed out. Some improvement of China Work Safety Early Warning Information System is anticipated.