Advanced Materials Research Vols. 79-82

Abstract: ARMOR TPS panel is above the whole ARMOR TPS, and the metal honeycomb sandwich structure is the surface of the ARMOR TPS panel. So the metal honeycomb sandwich structure plays an important role in the ARMOR TPS, while it bears the flight dynamic pressure and stands against the flight dynamic calefaction. So the active environment of metal honeycomb sandwich structure is very formidable. We have to discuss any extreme situation, for reason of making sure aerial vehicle is safe. And high-frequency vibration is one of active environment. In this paper we have analyzed high-frequency vibration response of metal honeycomb sandwich structure. We processed high-frequency vibration experiment by simulating true aerial environment. Sequentially we operated high-frequency vibration experiment of metal honeycomb sandwich structure with cracks, notches and holes. Then finite-element analysis was performed by way of validating the experiment results. Haynes214 is a good high temperature alloy material of both face sheet and core at present, so we choose it in this paper.

Abstract: Sampling moiré method is useful to measure shape, displacement and strain distributions of multi-functional materials and structures. When a specimen grating pattern on an object is recorded by a digital camera, a moiré fringe pattern is obtained by sampling the digitized grating image with a constant pixel pitch. The method can analyze phase values from one image of a grating pattern. By using this sampling moiré method, the displacement measurement of land is analyzed to develop a landslide prediction system. The theory and the application for measuring the displacement of land are shown in this paper.

Abstract: In the paper, a three-dimensional model is developed with cellular automaton method based on a series of experiments and the self-lubricating mechanism analysis. The model is used to investigate the dynamic friction process of sweat self-lubricating composite during high temperature sliding. The sliding friction coefficient and the distribution of lubricant on the worn surface of the composite are calculated out by using the cellular automaton (CA) model. The agreement between the computing and experimental results shows the model developed in the paper can be effectively used to study the friction behaviors of the sweat self-lubricating composite at high temperature.

Abstract: . Pretreatments for copper-doped SiC particles made by an electroless-plating technique, the preconditions to attain good coatings, were conducted in order to obtain the active and clean surface of SiC particles. An orthogonal experiment method was used to determine the concentration of every pretreatment solution. The morphologies of the coatings were observed in a scanning electronic microscope(SEM), the composition of the coatings was analyzed by an energy-dispersive X-ray analysis (EDS), and the phases in the coatings were identified by a X-ray differtometer (XRD). The influences of pretreatment solution concentrations on the copper coatings quality of SiC particles were dealt with. The results showed that the pretreatment solution concentrations had great influences on the coatings quality of SiC particles. The obvious effects on the copper coatings derived from the coarsening solution concentration. The optimized copper coatings of SiC particles were uniform and dense, no bare SiC particles were seen and the interfaces between SiC and Cu bonded well. The high quality and low cost coatings were also obtained after the expensive PaCl2 activating agent had been substituted for AgNO3.

Abstract: Zn plated on Cu plate from 0.65 mol/dm3 alkali zincate solution in 8 mol/dm3 KOH bath Electrolysis was carried out as current density of 10 - 100 mA/cm2. The sonication was prepared 40 kHz. The current efficiency was 76.1 % at 10 mA/cm2 in 0.10 mol/dm3 zincate and 100 % in 0.15 mol/dm3 zincate at 50 mA/cm2. The current efficiency and thickness of diffusion layer affected with the agitation of micro-jet. Surface of film was smooth and dense as particle crushed down with the shockwave pressure. (112) plane moved horizontally to <113> direction under the compressive stress or shearing stress.

Abstract: A special bifilar 40t electroslag remelting(ESR) furnace for slab products has been fabricated to produce heavy plates for special application. The slab ingots were rolled to heavy plates, and then the mechanical properties of which were investigated. The impact toughness of heavy plates with different position, directions and under welding condition were performed at the temperature ranging from -70°C to room temperature. The tensile experiments at room temperature were carried out to check the tensile properties of heavy plates in different position, directions and under welding condition. The secondary cooling technology developed improves greatly the quality of solidification. Adjusting taper of the mold and using CaF2-CaO-Al2O3-SiO2-MgO slag are necessary for improving surface quality of the ESR slab. The ESR slabs with the maximum thickness of the world in size of 980 mm thickness, 2000 mm wideness and 2800 mm length have been produced successfully. The heavy plates with 410 mm in thickness can be obtained after rolling the 40 tons ESR slabs. The results of mechanical properties show that the heavy plates produced by ESR furnace for slab products exhibits excellent ductility, impact and isotropic properties in different position, directions and under welding condition.

Abstract: In this paper, polypropylene fiber and SBR polymer latex are added into cement mortar to improve the toughness. Using two flexural toughness test methods of ASTM-C1018 and JSCE-SF4, the ratio of compressive strength to flexural strength (σC/σF for short) and flexural toughness index are used to evaluate the toughness of the cement mortar. The experimental results show that, comparing to the control cement mortar sample, when the SBR polymer mass percent of 20% and the polypropylene fiber volume percent of 1.0%, the σC/σF is 2.17, reduced by 59.2%, the ASTM toughness index I5, I10, I30 is 2.86, 2.95, 3.16 respectively, increased by 63.4%, 58.6%, 68.1% respectively, the JCI toughness index is 13.1, increased by 258%. Based on the SEM, adding SBR-polymer into cement mortar can form the polymer transition layer between the interfaces of polypropylene fibers and cement matrix, from XRD test, SBR polymer latex has no significant influence on the cement hydration after 7d curing. This research provides some useful references for the application of this new material.

Abstract: A method to estimate the thermodynamic properties of Multi- component white gold alloys from those of constitutive binary alloys was proposed. The Miedema's theory and Chou model. were used to calculate the formation enthalpies of Au–Cu–Ni-Zn-RE alloys. The agreement between the calculation and experiment is reasonable. Formation enthalpies of Au–Cu–Ni-Zn-RE and relative stability of their intermetallic compounds were predicted with present method.

Abstract: In order to improve the interlaminar mechanical properties of CFRP laminate, hybrid CFRP/VGCF laminates have been fabricated by newly-developed powder method. The critical load at crack growth Pc and fracture toughness GIC have been found to be increased with VGCF interlayer through double cantilever beam (DCB) tests. Fracture surfaces of DCB specimens have also been observed to interpret this improvement mechanism. Moreover, numerical simulations using finite element method (FEM) with cohesive elements have been carried out to analyze the delamination propagation. The numerically obtained interlaminar tensile strength of hybrid CFRP/VGCF laminates has also been verified to be higher than that of base CFRP laminates.

Abstract: In this paper, attapulgite(AT)/nature rubber (NR) composites have been prepared through melt blending process. First, different types of attapulgite were prepared.Secend,Fourier infrared spectroscopic (FTIR) was used to analyze attapulgite.Then,different types of attapulgite were filled into natural rubber according to different proportion.Finally, The mechanisms of composites were analyzed. The results showed that siliane coupling agent Si-69 can improve the dispersion of calcined attapulgite and enhance the chemical interfacial adhesion.