Applied Mechanics and Materials Vols. 513-517

Abstract: To make full use of waste clay bricks, we made recycled coarse aggregate by waste clay bricks and used it in self-compacting recycled concrete. In order to improve the utilization rate of recycled coarse aggregate and realize good workability, we adopted skeleton dense accumulation method. With the fitted curve method, we obtained an accumulation curve of recycled coarse aggregate with reasonable gradation. Under the same conditions, we made contrast test with the recycled coarse aggregate by different gradation way. Through contrast test, we found that the recycled concrete with skeleton dense accumulation method has better performance in strength and workability, and his method improved the utilization rate of the recycled coarse aggregate.

Abstract: Ceramic coatings were prepared on Ti6Al4V alloy surface by applying micro-arc oxidation (MAO) technique. K₂Cr₂O₇ was added into the aluminate-based composite electrolyte for preparing coatings containing Cr. The coatings' morphologies were observed using SEM and their composition was characterized using XRD and EDS. Research shows that the working voltage of MAO reaction was lower after adding K₂Cr₂O₇. The SEM pictures show that the average diameter of micropores decreased while the number increased as the K₂Cr₂O₇ concentration increase. The coatings contain rutile TiO₂, anatase TiO₂, aluminium titanate (Al₂TiO₅) and Cr_0.222Ti_0.778O_1.889 (when adding 1.5g/L K₂Cr₂O₇). The EDS results show that all coatings contained Cr after adding K₂Cr₂O₇ into electrolyte. After immersion test for half year, results show that ceramic coating containing chromium has lower anti-biofouling properties than the substrate.

Abstract: According to recent researches, aluminum alloy is an ideal choice for solar energy storage technology. But the erosion nature limits its promotion and application. Therefore, it is particularly important to research the corrosion behavior and the corrosion mechanism. In this paper, the 304 stainless steel was used as the container material. By analyzing the corrosion kinetics curves, the erosion thickness increases and the erosion rate decreases with the erosion time extension. Electron probe, X-Ray Diffraction (XRD) and other instruments were used to research the corrosion behavior and mechanism of erosion products. The results show that the erosion form is uniform corrosion. The erosion phenomenon is due to the diffusion corrosion of Al element. Si, Al_0.5Fe₃Si_0.5 compound and Al₉₅Fe₄Cr compound in the erosion layers can retard the diffusion of Al.

Abstract: The novel two reactive polymers (L-PPQF and V-PPQF) were designed and synthesized with chemical reaction activity. Take the in-situ reaction with benzene-1,2-diamine for example, it was the realization of multi-tune in photoelectric function of the matrix polymer through the change of reactive polymer structures.

Abstract: The triplet exciton is more benefit for organic solar cell than singlet exciton. PQ with long lifetime is an effective unit to form triplet exciton in polymer backbone. PPQF shows much higher PV response than PDHF which is attributes to the efficient exciton dissociation process occurred in PPQF.

Abstract: The corrosion behavior of duplex stainless steel immersed in nutrient-rich simulated seawater without deep sea bacteria and with deep sea bacteria (Erythrobacter pelagi sp.nov) was studied. The effect of chloride ions and presence of deep sea bacteria on corrosion resistance was investigated. The occurrence of localized corrosion (Viz. pitting and crevice corrosion) was examined using visual inspection and SEM-EDX. Electrochemical impedance spectra were used to study the effects of deep sea bacteria on duplex stainless steel and inferences were made. Most significantly was the reduction of pitting resistance potential with increase in exposure time.

Abstract: The starch-based foam was preprared by moulding process and studied the effects on the density, mechanical properties, hardness and water absorption capacity of the foams with different polyvinyl alcohol (PVA) contents. The microstructure and crystallization of the foam was observed through the scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the addition of PVA could better improve the material mechanical properties, the elongation at break was increased from 15.72% to 113.86% while the hardness was reduced from 37.3 to 16.7. The density of foam reached to the minimum value of 0.261 g/cm³, attaining to the maximum tensile strength of 1.08 Mpa. SEM and XRD showed that the compatility of starch and PVA was very good and the addition of PVA helped to improve the bubble distribution of foam and inhibit the retrogradation of starch granules.

Abstract: 5A zeolite supported Gold-Palladium (Au-Pd) bimetallic were prepared and used in vapor phase oxidation of ethylene to synthetize vinyl acetate (VA). The chemical composition of Au-Pd/5A zeolite catalyst was analyzed by a combination of atomic absorption spectrometry (AAS). The structure of Au-Pd/5A zeolite catalyst was characterized by a scanning electron microscopy (SEM) and X-ray diffraction (XRD). The catalytic activity of the Au-Pd/5A zeolite catalyst under laboratory conditions were investigated in vinyl acetate synthesis by a kind of the fixed bed reaction device. The AAS testing showed that Au and Pd supported rate were increased up to the optimum value 91.22% and 93.91% respectively at the ratio of Au/Pd=0.87. The SEM analysis results indicated that Au-Pd alloy particles of 5A zeolite catalyst can grown up and reunited obviously through before and after reaction. The XRD analysis results showed that diffraction peak of Pd (111), Pd (200), Au (111) and Au (200) became sharp gradually with the extension of reaction time, crystalline phase composition and grain size of catalyst became bigger gradually. The results about catalytic activity of the Au-Pd/5A zeolite catalyst shown that with the increasing of the Au/Pd ratio, the space-time yield and selectivity have a best value respectively; when the ratio of Au/Pd=0.87, the space-time yield were 702g/(Lh) and the selectivity were 92.8% at the ratio of Au/Pd =1.13.

Abstract: Damage caused by low-velocity-impact in laminated composite will significantly reduce the strength of the structure. A new numerical model is proposed for the research on the impact induced damage of laminated composite. Multiple forms of damage within and between layers are considered in this model. The cohesive contact technology is used to simulate the bonding properties between layers. The model can describe the information of delamination more accurately and efficiently. Then, a study is carried out to investigate the relationship of delamination and matrix cracking caused by low-velocity-impact. The result reveals that the area and axis of the delamination zone is affected by the direction of the matrix cracking zone.

Abstract: The effects of high temperature deformation on transformed microstructure and transformation amount in a high strength bainitic steel were investigated. It indicates that isothermal bainitic transformation is promoted by high temperature deformation. The transformed bainite microstructure is also affected by high temperature deformation, i.e. deformation retards the growth of bainite sheaves, leading to shorter banitie plates. The present study is useful to further understand the effects of ausforming on bainitic transformation.