Advanced Materials Research Vols. 239-242

Abstract: Base on engineering application need, the subject introduce microcapsule that contains adhesive into cementituous composite for realizing the self-healing characteristics of cracked concrete. The technique has good industry feasibility, process operability, and reproducibility of self-healing characteristic. It is can resolve partial problems that other current self-healing methods are facing.

Abstract: As interferences are introduced from main-lobe direction which results in tar-get signal are masked by interference, traditional adaptive beam-forming can not suppress main-lobe interferences effectively. Polarization filtering is a main method to suppress the interference in radar and other sensor systems. Based on the spatial polarization characteristic (SPC) of antenna, a spatial virtual polarization filter (SVPF) is proposed by constructing polarization decomposition and polarization estimation of the received signal. A generalized construction method of SVPF is provided, the performance of the SVPF is given, and simulation results of the interference suppressing are illustrated. It is indicated that the proposed filter is a valid filtering technique for interference canceling. SVPF made single polarized radar own polarization information processing ability which improved radar working performance.

Abstract: In order to improve the wear resistance of mild steel products, the Fe-based alloy layer was melted on the surface of mild steel by high-frequency induction cladding. Using scanning electron microscopy, energy dispersive spectroscopy and x-ray diffraction observation of microstructure of the alloy coating, wear resistance of the coating was evaluated. The results showed that: between the coating and the substrate is metallurgical bonded; The microstructure of coating layer was compact actinomorphous structure with plentiful nubby and strip eutectics; Actinomorphous structure was mixed structure of martensite and γ alloy solid solution covered with a large number floriform and dendrite eutectic; The coating has high hardness and good wear resistance.

Abstract: ZnO films were deposited on nanostructured Al (n-Al) /glass substrate by RF magnetron sputtering. The results shows that the relation (I (002) /I (100) ≈ I annealed (002)/I annealed (100) ≈1.1) shows the rough n-Al surface is suitable for the growth of a-axis orientation. Meanwhile, the influences of substrate roughness, crystallinity and (101) plane of ZnO film deposited on n-Al layer have been discussed. XPS implies more oxygen atoms are bound to Aluminum atoms, which result in the increase of high metallic Zn in the film.

Abstract: A novel polystyrene modified ethoxycarbonyl thiourea resin(PSETU) was synthesized by polymer grafting of aminated polystyrene and ethoxycarbonyl isothiocyanate. The adsorption capacities of PSETU follow the order: Au(III) > Cu(II) > Zn(II) > Ni(II) > Fe(III) > Ca(II) ≈ Mg(II). The adsorption capacity for Au(III) increases with the increase of contact time, temperature and initial concentration of Au(III). The adsorption data fit Boyd’s diffusion equation of liquid film, Langmuir adsorption isotherm and Freundlich adsorption isotherm. The maximum adsorption capacity of PSETU calculated by Langmuir isotherm equation is 3.485 mmol/g, and the separation factors of PSETU for Au(III)-base metal ions are above 380. According to XPS results, the functional atoms of PSETU coordinate with Au(III) during the adsorption process.

Abstract: The effect of stepped solution treatment on the mechanical properties and the microstructure of AA7085 have been investigated compared to AA7050. Optical and electron microscopy observation and electron probe microanalysis were used to analyze the microstructure and tensile fracture surface of AA7085 and AA7050 processed via various treatment schedules. Besides, X-ray diffractometer and differential scanning calorimeter were used to seek the differences of microstructure characters between AA7085 and AA7050. The results indicate that higher content of Zn along with lower content of Mg and Cu and strictly confined Fe and Si made the matrix of AA7085 get a larger single phase and a higher melting temperature of multi-phase eutectics. By using a lower temperature pretreatment, the initial melting temperature of the alloys can be increased. Consequently complete dissolution of remnant constituents was achieved without overheating. Based on thermodynamics statistic theory, the supersaturation degree of the matrix and the density of cavity may be increased with the elevation of the lattermost solution temperature, which resultes in the increase of fracture toughness and optimization of the microstructure after aging.

Abstract: The effect of different welding methods on joints’ microstructure and properties of A240-S32205 duplex stainless steel was studied. The result showed all joints using GTAW and SMAW can attain good phase ratio and corrosion resistance. But the comprehensive mechanical characteristics of joint using GTAW was better than that of SMAW joint with acid electrode. Besides, the low temperature impact performance was not ideal in joints manual welded with acid electrode. The HAZ was identified as a weak zone where the corrosion resistance was the worst and in which the third detrimental metallic phase was more liable to emerge than in weld zone.

Abstract: Activated carbon for electric double-layer capacitors was prepared from bamboos by activation with KOH solution through heating by microwave radiation. The influence of the mass ratio of KOH to bamboo, power and radiation time of microwave was studied. The behavior of charge/discharge, cyclic voltammetry and AC impedence of bamboo-based activated carbon electric double-layer capacitor was investigated. The results indicated that the specific capacitance of bamboo-based activated carbon supercapacitors can reach 277.46F/g while KOH to bamboo is 6:1 and the power and radiation time of microwave are 720W and 12 minutes respectively. Moreover, the electric double-layer capacitor using the activated carbon as electrode materials has good charge/discharge properties and cycling performance.

Abstract: According to the weak rigidity characteristics of thin-walled parts, the material parameters and deformation tools are taken into account. In this paper, the finite element model of high-speed milling process is systematically studied by a large-scale finite element analysis (FEA) software DEFORM-3D with the modified Johnson-Cook model. The simulated results of cutting force, chip morphology, effective stress, effective strain and cutting temperature in deformation zones of thin-wall part are analyzed. On the basis of simulation results, cutting force of high speed milling on thin-wall part is verified. Comparing to the experimental results, the simulated results of cutting force, chip morphology, effective stress and cutting temperature in deformation zones of high speed peripheral milling indicate good consistence and the models established can be used to accurately predict the thin wall deformation. Therefore, numerical simulation method for the thin wall milling deformation control and provide a new way of compensation.

Abstract: A new superparamagnetic material was synthesized by a method involving the use of dimethylolpropionic acid (DMPA) and ferrous powder in N,N-dimethylformamide (DMF) as a solvent in this work. Through the magnetic balance measurements, fourier transform infrared spectrophotometry (FTIR) and so on, it was found that the synthesized material emerged superparamagnetism at room temperature. Additionally, there was a regular change for the magnetic response behavior with different temperature and time in some way.