Advanced Materials Research Vols. 194-196

Abstract: Internal oxidation is one of the most common methods to produce in situ nano oxide particles dispersion strengthened copper base composite (ODSC) in powder industry. In this paper, a simplified internal oxidation method was proposed to prepare ODSC composite by using thin strip of Cu-Al alloy. The effects of the addition of rare earth element yttrium and cold deformation on the microstructure and mechanical properties, such as hardness and tensile strength, were investigated briefly. Results show that after 80% deformation, the crystalline grains of the composite matrix plastically deformed in elongated shape to a certain direction as banded fiber structure. The addition of trace element yttrium and cold information increase the hardness and tensile strength of the Cu-0.35Al₂O₃(Y) composite remarkably, respectively.

Abstract: With the reaction between titanium (Ti) sponge, high purity aluminum (Al) and TiC/Al inter-alloy, non-consumable arc melting technique has been successfully used in situ synthesize Ti matrix composites of Ti-40Al-2.0C. The composites oxidized at 700~900°C for different time in static air. The influences of oxidation time and temperature to oxidation kinetics of composites were analyzed. The surface morphologies and components of the oxidation scales were examined by scanning electron microscope (SEM) with energy dispersive spectrometer (EDS). The results show that the isothermal oxidation kinetic curves of composites mainly follow parabolic rate law. When the composites oxidized at low temperature for short time, the color of oxidation surface is olivine which is similar to the color of the matrix and the oxides exist in non-uniform mixture state of Al₂O₃ and TiO₂. While the composites oxidized at high temperature for long time, the color of oxidation surface is deep yellow and the oxides are mainly columnar hexagonal TiO₂.

Abstract: The existential state of protein in complexes directly affects the performance and applications of the composite materials. The interlayer space changes of montmorillonite in the protein / montmorillonite (MMT) composite were identified by X-ray diffraction (XRD). And the interaction between protein and MMT were analyzed by Fourier transform infrared spectrometry (FT-IR) and UV/vis spectrophotometry. The loading amount of bovine serum albumin (BSA) onto MMT was calculated from the TG data. The types of adsorption isotherm of BSA onto montmorillonite were analyzed. From the above analysis, it can be concluded that the structure of proteins in the montmorillonite interlayers has been changed, and the hydrogen bond and Van der Waals force between the BSA molecules and montmorillonite crystal layers are intensified. The α-helix content of BSA molecules reduces while random coil increases. The protein shows a state of being squashed.

Abstract: In this paper, a novel sulfonic acid-functionalized carbon/loess composite was prepared using sucrose as carbon source and loess as raw material. The characterization results shown that plenty of carbon particles distribute on the surface of the composite, and an abundant of SO₃H groups were successfully introduced onto the surface of the prepared composite through incomplete carbonization of sucrose and sulfonation of carbon particles. The adsorption capacity of the prepared composite for typical heavy metal ions also was investigated and compared with activated carbon, the results show that the composite shows excellent adsorprion performance, and the adsorption capacity for Fe³⁺, Pb²⁺, Cu²⁺, Cd²⁺, Ni²⁺ can reach about 412%, 249%, 153%, 134% and 120% of the capacity of activated carbon, respectively. The prepared composite with excellent adsorption performance could be used as a low-cost alternative to activated carbon for the removal of heavy metal ions from wastewater.

Abstract: Three-dimensional (3D) integrated cellular woven structures are formed by binding layers of typical 3D woven structures together in the thickness direction with binding threads. On the basis of the geometric model established during previous work, the orientation angle of binders in the basic structure was analyzed firstly, and then the orientation angle of binders and warps in the 3D integrated cellular woven structure were also studied. And at last following conclusions could be gotten: Firstly, the orientation angles Q_b of the binders will be larger as the regularizing filling density p_w increasing when other parameters (λ_w ，N_ft ，b_b ) are all the same. It turns out the adjusting function of the regularizing filling density is a little sensitive to the orientation angle of binders in the basic structure. Secondly, the orientation angle Q_cj of the warps will be larger as the regularizing filling density p_w increasing when other parameters (λ_w ，n_d ，b_b ) are all the same. It turns out the adjusting function of the regularizing filling density is a little sensitive to the orientation angle of warps for 3D integrated cellular woven structures.

Abstract: Small samples of Chinese fir/TiO₂ Composite were prepared using sol-gel method and microwave assisted liquid phase deposition (MWLPD) method for the first time. Results of antibacterial test show that during a one year test the samples exhibited prominent, broad-spectrum and long-lasting antibacterial performance, but were also influenced by light exposure and temperature.

Abstract: We proposed using Ti-Al and Ti-Cu laminated composites instead of single Ti electrode metals, as well as studied the difference in performance between laminated composite electrode materials and pure-Ti electrode. The analysis of the conductivity and electrochemical performance of electrode matrix material indicates the result that the improvement of matrix material by using Ti-Al and Ti-Cu laminated composites, better performance for conductivity of electrode, and be beneficial to homogenize the electrode surface potential and current distribution and promote electrocatalytic activity between polar plates. Whereas comparison between Ti-Al and Ti-Cu laminated composites, Ti-Cu laminated composites is better in performance.

Abstract: The result shows: If probabilistic methods were used to conduct compliance analysis for composite structure damage tolerance. When the impact energy is low, calculated result should conservatively use probabilistic methods of Weibull distribution fitting; when the impact energy is high, calculated result should conservatively use probabilistic methods of logarithmic linear fitting.

Abstract: Zinc sulfide (ZnS) nanocrystals with graphite sheaths were obtained from pyrolysis of bis(2-mercaptobenzothiazolato)-zinc (II) in nitrogen atmosphere at 400°C for 2 h without any additional sources. X-ray diffraction patterns showed that the ZnS crystals belonged to the hexagonal system. Transmission electron microscope studies revealed that ZnS/C nanocrystals were well-dispersed and had a diameter of 20~30 nm. The possible mechanism for the formation of the interesting well-dispersed microstructures was also proposed.The special structures of ZnS nanocrystals with graphite sheaths may have potential applications in nanoelectronics and photonics. This simple approach may be applied to the synthesis of other semi-conductor nanocrystals.

Abstract: Micro-sized aluminum (Al) reinforced silicone rubber composites were prepared, and the thermal properties of the composites were investigated in term of composition, shape, and surface modification of Al particles. The results demonstrated that the incorporation of Al particles into the composites improved the peak vulcanization temperature, and decreased the thermal stability behavior of the rubber; furthermore, the shape, concentration, surface treatment of Al particles and temperature had an effect on the thermal conductivity. The thermal conductivity increased obviously with a rise of Al particles concentration, as well as with a surface modification of filler. The flaky Al particles reinforced rubber showed a distinct higher thermal conductivity as compared to the spherical Al particles.