Advanced Materials Research Vols. 915-916

Abstract: Nanotubes exhibiting great mechanical properties are expected to produce significantly stronger and tougher cement composites. The effects of Carbon Nanotubes to cement based composites are investigated in this paper. The flexural strength and the compressive strength of the CNTs cement composites under different content of are tested and the toughness indexes are analyzed. The results show that CNTs have a positive effect on the brittle failure of cement composites, and that the compressive strength and flexural strength of 0.10% CNTs cement composites are significantly increased. The toughness index of 0.05% CNTs cement composites is relatively higher.

Abstract: The influence of Fe on microstructure and the expansion coefficient and thermal conductivity of Al-30 wt.% Si alloy was studied. Results show that the primary silicon morphology and size changed significantly after joining the Fe, by angular blocky primary silicon sheet or plate into small pieces and then into a polygonal large lump, edge and angle are passivated. As the content of Fe is 0.3 wt.%, material expansion coefficient and high thermal conductivity. Later, with the increase of the content of Fe, alloy point defect and line defect, surface defect and large area defect increase, the thermal conductivity of materials and inflation performance declined. When the content of Fe is 0.1 wt.%, materials with high thermal conductivity and low thermal expansion coefficient, the heat storage performance impact is minimal.

Abstract: Pyrrole and m-toluidine copolymer (P(PY/MT)) / montmorillonite (MMT) Composites were prepared by in situ chemical polymerization of pyrrole with m-toluidine monomer in the presence of montmorillonite. The structural, morphological and thermal properties of these composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). X-ray diffraction result for P(PY/MT)-MMT illuminated the intercalation of P(PY/MT) copolymer between the clay layers. The FT-IR result showed the successful incorporation of montmorillonite clay in the prepared P(PY/MT)/MMT composite. The higher thermal stability of high MMT content rate might be attributed to its higher chain compactness due to the interfacial interaction between the P(PY/MT) and the clay.

Abstract: Based on the mechanical properties experiment of the glass fiber reinforced concrete with 0%0.6%0.8% and 1% glass fiber volume fraction, the mechanics property such as tensile strength, compressive strength, flexural strength and flexural elasticity modulus are analyzed and compared with the plain concrete when the kinds of fiber content changes. The research results show that the effect of tensile strength and flexural strength can be improved to some extent, which also can serve as a reference or basis for further improvement and development the theory and application of the glass fiber reinforced concrete.

Abstract: A new Al₂O₃ particle reinforced Al matrix composite was fabricated through in-situ chemical reaction between Al and glass powder. The microstructures and element distributions of the composite were observed and analyzed through OM, SEM and EDS, respectively. The results show the reinforced Al₂O₃ particle synthesized by in-situ chemical reaction are aggregated on the grain boundary. The grains can be refined with the increasing of powder. Eutectic silicone with granulous shape was found in the microstructure, which attributes to the modification of Na and Ca to eutectic silicone.

Abstract: Applying continuous casting to magnesium alloys is one of the recent issues due to relatively less defects inside the as-cast billet. In this study, homogeneity in the chemical composition of a commercial continuously-casted ZK60A billet was investigated. Density distribution depending on the distance from the center of the billet was measured, and the difference in density was analyzed based on the measured chemical composition.

Abstract: Experiment prepared polystyrene microspheres with a diameter of 722nm, the template of polystyrene microspheres obtained through the self-assembly. The copper atoms fill the voids of the template by electrochemical deposition, after removing template, copper surface obtain regular arrangement of spherical cave structure. Copper surface with spherical cave modified fluorosilane by chemical method, The contact angle of the surface is 156.3 ° through contact angle measuring. Superhydrophobicity of prepared copper surface is because of two important factors, one is regular microstructure of spherical cave, the other is modification of fluoroalkylsilane.

Abstract: Different optical models were adopted to fit theoretical simulation curves of a SiO₂ ultra-thin film with a density of 2.2 g/cm³ and a thickness of 6nm grown on Si wafer. The results indicate that thickness obtained from fitting decrease linearly with increase of film density. An improved optical model (density of thin film of 2.4g/cm³, roughness of surface of 0.4nm, roughness of surface of 0.3nm) was obtained according to the above analysis and the GIXRR results of our previous work. The improved model could give more accurate thickness value of ultrathin film with thickness less than 10nm. It was employed in the thickness fitting for thermal oxidized SiO₂/Si thin film with nominal thicknesses of 2, 4, 6, 8 and 10nm. The results were 2.61, 4.07, 6.02, 7.41 and 9.43nm, decreased by 13.8%10.3%8.1%7.3% and 6.6%, respectively, compared with the results calculated from the traditional model.

Abstract: (CrTiNb)N hard reactive films are prepared by multi-arc ion plating technology using the combination of Ti-Nb alloy target and Cr target. The high speed steel (HSS) is adopted as substrate. The surface and cross-fracture morphology, the surface compositions and the phase structures of the as-deposited (CrTiNb)N films are observed and measured by scan electronic microscope (SEM) and X-ray diffraction (XRD). The mechanical properties including the micro-hardness, the adhesion between film and substrate, the friction and wear resistance of the as-deposited (CrTiNb)N films are systemically investigated. The effects of deposition bias voltage and the addition of Nb element on the as-deposited (CrTiNb)N films are discussed. It is revealed that the optimally comprehensive performances including the micro-hardness, the adhesion and also the friction resistance can be achieved by the (CrTiNb)N hard reactive films with bias voltage of 200V.

Abstract: (TiAlNb)N hard reactive films are prepared by multi-arc ion plating technology using the combination of Ti-50Al (at%) and Ti-25Nb (at%) alloy targets. The high speed steel (HSS) is adopted as substrate. The surface and cross-fracture morphology, the surface compositions and the phase structures of the as-deposited (TiAlNb)N films are observed and measured by scan electronic microscope (SEM) and X-ray diffraction (XRD). The mechanical properties including the micro-hardness, the adhesion between film and substrate, the thermal shock resistance of the as-deposited (TiAlNb)N films are systemically investigated. The effects of deposition bias voltage and the addition of Nb element on the as-deposited (TiAlNb)N films are discussed. The optimally comprehensive performances, especially hardness and thermal shock resistance, exhibited by (TiAlNb)N films with bias voltage of 100V.