Advanced Materials Research Vols. 415-417

Abstract: In this paper, we discussed the kinematics simulation of a six DOF (degree of freedom) industrial robot, modeling the robot with PRO/E. D-H coordinate transformation method is used to establish coordinates of robot kinematics mathematical model and the target matrix. The powerful symbolic computation of MATLAB functions is used to analyze the equation, and the inverse kinematics solution is obtained. The joint trajectory of the robot in the implementation of task and workspace are worked out through the forward kinematics solution.

Abstract: Under the catalysis of Co metal, the nanosized titania could be grown on Ti substrate at elevated temperature under a gas mixture of N₂, O₂, CH₄ , and H₂O. The nanosized titania was characterized by scanning electron microscope for its morphology, and by an energy dispersion spectrometer for its composition. The results showed that the straight and long titania nanowire could be formed at 900°C under a gas mixture of N₂, O₂, and CH₄. When H₂O vapor was added to the gas mixture, the titania nanowire became somewhat curved. The tiania nanowire was oxygen deficient, i.e. TiO_2-X.

Abstract: The divergence of still point charge is zero in the vacuum passive space, but the divergence of moving point charge is not zero. In order to make the divergence of moving point charge in the vacuum passive space being zero, we must choose the coordinate in which moving point charge has the same velocity with the coordinate as a reference system.

Abstract: Fe-based system powder metallurgy in the as-sintered was investigated on pin-on-rolling wear tester for their dry sliding wear behaviour. The morphology of worn surfaces and wear mechanism were analysed by SEM. Results show the hot-forging deformation quenching and tempered considerably decreased the porosity and improved wear resistance, and compare with quenching microstructure, tempered microstructure has high wear resistance and match of strength-toughness. Fe-2.0Ni-0.4Mo-0.5C-0.6Cr alloy presented best wear characteristics. SEM observations of the worn surface revealed microploughing and plastic deformation and crack were the basic dry sliding wear morphology,and oxidative wear and delamination wear are dominant wear mechanism.

Abstract: Aim at the demand of feature modeling and recognition of engineering drawing, this paper put forward a mechanical file as real time defining and editing tool of feature, converting the restriction of parametric drawing to the same point relation, structure restriction and dimension restriction, marking the drawing structure of the file using of the extending data entity. So that the file can support the feature modeling and recognition, realize the structure management of engineering drawing.

Abstract: Nanocomposite thin film containing TiO₂ nanoparticles in polymethyl methacrylate (PMMA) is a new class of potential materials for optoelectronic applications. Among the various processing techniques for these nanocomposites, in situ sol−gel process is well known to be versatile as it enables control of the inorganic-organic interaction at various molecular, nanometer and micrometer scales. However, the resulting TiO₂ phase is largely amorphous, as a consequence of the relatively low processing temperatures. Therefore, the current research is aimed at enhancing the nanocrystallinity of TiO₂ nanoparticles in nanocomposites. For this purpose, pre-hydrothermal treatment was carried on the inorganic sols. The nanocrystallinity degree of the resulting TiO₂ nanoparticles was studied by XRD and FTIR. The studies showed that the nanocrystallinity of TiO₂ nanoparticles synthesized from the inorganic sol can be enhanced significantly by the pre-hydrothermal treatment, as a result of the completion of hydrolysis stage during sol-gel process.

Abstract: A new method for extracting spectrum feature of gas flucturation of aerostatic guideway is proposed. The flatness error of workpiece surface includes much errors information, and the information contains high frequency signal and low frequency signal, for these errors information, a new identification method of turning errors of workpiece based on the wavelet transform and power spectral density analysis is proposed. According to the focal variation character of wavelet and the energy value of power spectral density analysis, the feature of gas flucturation of aerostatic guideway from the measured flatness error of workpiece is extracted and identified.

Abstract: The Cu-Fe-P alloy C194 for lead frames was prepared using thermomechanical treatments (TMT)．The effects of deformation ratio of cold rolling and aging temperature on the conductivity and micro hardness of C194 alloy during TMT were studied by a low DC resistance tester and a Vickers hardness tester. The results showed that the effect of aging temperature on conductivity was relatively larger than that of deformation ratio. After a series of experiments, the optimized TMT process was obtained. The strip with 1.4mm in thickness was first rolled to 1.0mm and first aged at 500°C for 2 hours, and second rolled to 0.3mm and second aged at 450°C for 2 hours, and finally rolled to 0.2mm and stress-release annealed at 330°C for one hour. The final strip products would reach to the best properties, such as, conductivity was 68.5 %IACS and microhardness was 149.9HV.

Abstract: Constructed matrices and artificial neural network numerical simulation method are used to transform , regulate and control carbon black (CB) reactor, where nano-conductive carbon black (NCCB) of low resistivity and good dispersion can be produced on the base of coal tar-based CCB production process. This kind of high-quality CCB with corrosion resistance and low expansion is used in high power electrodes, capacitors, etc.

Abstract: The effect of different additives on thermal decomposition of phosphogypsum was investigated by means of a thermogravimetry coupled with a Fourier transform infra-red spectroscopy. These additives included C, CaO, Al₂O₃ and S. The temperature of thermal decomposition of phosphogypsum is about 1100~1320°C without any additives under the background of nitrogen. The temperature of the thermal decomposition of phosphogypsum decreased obviously with the addition of CaO, C and S. No influence was found for the thermal decomposition of phosphogypsum with the addition of Al₂O₃. As one of evolved products from the thermal decomposition of phosphogypsum, SO₂ production was discussed.