Advanced Materials Research Vols. 328-330

Abstract: Relationship between slip resistance of shoe sole and materials and floor conditions was studied by Mark II slipmeter in order to improve the slip resistance of shoe sole. The results indicate that all the materials of shoe sole and floor and the lubrication conditions of floor can affect the slip resistance of shoe sole. whereas the influence of the lubrication conditions of floor is more significant than the other two factors. Friction coefficient of rubber was highest in the three shoe sole materials. Friction coefficient of terrazzo was highest in the three floor materials. That is to say that the slip resistance of rubber is best in the three tested materials and the slip resistance of terrazzo is best in the three floor materials. Friction coefficient of oil condition was lowest among the three floor conditions and the probability of slips was very high.

Abstract: The composite materials with a nominal composition of Cr₂Nb-24wt.%Ti were fabricated by mechanical alloying followed by hot pressing. The microstructures and properties were investigated on the composites contained with Laves phase prepared through 20 hours mechanical alloying of chromium, niobium and titanium elemental powders and hot pressing at 1250°C for half an hour. The results indicate that the near full-dense Laves phase Cr₂(Nb,Ti) based alloy with homogeneous composition and microstructure is obtained by mechanical alloying and hot pressing techniques. The dispersed soft second phase Nb solid solutions with the fine grain size less than 1μm are distributed uniformly on the matrix. The sample has a relative density of 99%, fracture toughness of 5.32MPa•m^1/2 and compress strength of 2080MPa. Due to the effect of fine-grain and alloying addition, the toughening of the Cr₂(Nb,Ti) based alloy has been fully realized.

Abstract: Radar absorbing structures (RAS) can’t only load bearing but also absorb electromagnetic wave energy by inducing dielectric loss and minimizing reflected electromagnetic waves. Therefore, the development of the RAS haves become important to reduce RCS of the object. These composites possess excellent specific stiffness and strength. The electromagnetic wave properties of RAS can be effectively tailored by controlling the content of the lossy materials. Radar absorbing structures composed of glass fibers, carbon fibers and epoxy resin filling with carbon nanotubes (CNTs), was designed and prepared. Permittivity of the composite was measured by using a network analyzer, HP8510B. The contents of composites were observed to be different from each composite. Reflection of electromagnetic waves energy of RAS was calculated by using the genetic algorithm, it was discovered that the composites can be applied to design an optional RAS composites filling with CNTs.

Abstract: Through the observation of photomicrographs of resin regions around Z-pin ends, the basic hypothesis of the elliptic configuration of resin regions in the X-cor sandwich were proposed. The parametric equations for describing the microscopic structures of resin regions were given. Then the geometric analysis model of X-cor sandwich was established. The finite element software ANSYS was used to establish the finite element model of the shear modulus and the shear modulus was calculated. The error range of finite element analysis is between ±10%. So the rationality of finite element model is verified and the finite element model can be used to forecast the shear modulus.

Abstract: This paper describes a way to realize the manufacture of nanowires in detail, which would be discussed mainly on the implement methods as well as the specific craft. Accounting for the cost, this way relied relative fewer on the high-precision photoetching machine, while it took use of the excellent surface of Si and SiO2, applying oxidation to diminish the width of these wires[1]. The paper would cover some regulations of conditions and concrete steps to present a whole technical process.

Abstract: This article presents a study on the adequate application of blast furnace slag to replace quartz sand in cementitious self-leveling mortar. The results show that the strength of mortar decreases slightly, because slag sand can drag in some air bubbles which can form holes in the harden mortar. And compared with quartz sand, its compression strength loses only 4.6 % on 28d age. the proportion of 75 % slag sand and 25 % quartz sand was the best proportion as coarse filler.

Abstract: Lead-free piezoceramics (K_0.5Na_0.5)_0.94-3xLi_0.06La_xNbO₃ were synthesized by the conventional solid-state reaction process. The effect of La-doping on the phase structure and electrical properties of (K_0.5Na_0.5)_0.94Li_0.06NbO₃ ceramics was investigated. X-ray diffraction analysis showed that the crystal structure of the ceramics changed from coexistence of orthorhombic and tetragonal phases to pseudo-cubic phase with the increase of La-doping level, and the change of phase structure seriously weakened the dielectric, ferroelectric and piezoelectric properties of the ceramics. In addition, it was found that the La-doping improved the density of the ceramics and the ceramics became dense. Meanwhile, the ceramics with La-doping displayed a relative lower loss tangent (tanδ) from room temperature to approximately 350°C.

Abstract: Lead-free piezoelectric ceramics Sr₂Bi_4-xGd_xTi₅O₁₈ were prepared by conventional solid-state reaction method. Pure bismuth layered structural ceramics with uniform gain size were obtained in all samples. The effect of Gd-doping on the dielectric, ferroelectric and piezoelectric properties of Sr₂Bi₄Ti₅O₁₈ ceramics were also investigated. It was found that that Gd³⁺ dopant gradually decreased the Curie temperature (T_c) with the lower dielectric loss (tand) of SBTi ceramics. In addition, Gd-doping with appropriate content improved the ferroelectric and piezoelectric properties of the SBTi ceramics. The piezoelectric constant (d₃₃) of the Sr₂Bi_3.9Gd_0.1Ti₅O₁₈ ceramic reached the maximum value, which is 22 pC/N. The results showed that the Sr₂Bi_4-xGd_xTi₅O₁₈ ceramic was a promising lead-free piezoelectric material.

Abstract: A rotary magnetorheological (MR) damper for a semi-active suspension was developed, laboratory tested. The working principle and features of the rotary MR damper was outlined and its theoretical model was developed. Full optimization of the magnetic design was accomplished with the help of magnetic finite element software ANSYS in the limited space. The parameters of the MR damper’s theoretical model were identified by a series of harmonic loading tests. It is demonstrated that the damping capacity of this MR damper is a function of strain amplitude and field strength, and it is feasible to use for the life application in terms of force characteristics.

Abstract: A new type of ZnO/Ag micro hybrid material has been fabricated by a facile wet chemical method using citrate as a crystal growth modifier. The morphology and component of ZnO/Ag hybrid material were characterized by SEM and XRD. It is shown that the platelike crystals connect together by means of embedding. The sample is composed of wurtzite ZnO and face-centered cubic Ag. The results of XPS, UV-Vis and PL spectra verify the electron transfer from Ag to ZnO. The photocatalytic test with Rhodamine B (RhB) as a representative dye pollutant shows that the ZnO/Ag hybrid material exhibits an improved photocatalytic activity.