Papers by Keyword: Processing Parameter

Abstract: This paper mainly introduces a new method of preparation of microcellular material, this method can be divided into three stages: kettle with saturation pressure, heating foaming, flattening and calendaring. During the process of supercritical CO₂ saturated, different materials need reasonable control parameters such as saturation pressure, saturation temperature and saturated time, and the values of saturation temperature and saturation pressure will directly affect the permeability of supercritical CO₂. During the process of heating foaming, it needs to strictly control the parameters such as foaming temperature and foaming time, because the bubble density and bubble size are closely related to the two parameters. During flattening and calendaring process, it is important to control temperature and speed of roller reasonably to avoid the phenomena of collapse in bubbles. There are no harmful substances emissions using this method to produce ultrathin microcellular material, which can also protect the environment.

Abstract: The microstructure and corrosion resistance of Fe-based amorphous coatings prepared by laser remelting after arc spraying were studied. The laser remelting process was carried out under different energy inputs, and the processing parameters varied with the different currents, pulse widths and scanning speeds. The corrosion behavior of the coatings in 1 mol/L NaCl solution was studied through potentiodynamic and potentiostatic polarization test. The morphology and microstructure of the coatings were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical analyzer. A Vickers hardness tester was also used to measure the microhardness of the coatings. The analysis of the microstructure shows that the amorphous coatings are composed of amorphous matrix and nanocrystalline phases. The diffusion of elements indicates a metallurgical bonding between the coating and substrate. The electrochemical corrosion results obtained from the Tafel polarization curves verify that the amorphous composite coatings prepared by different methods show no significant differences in their corrosion resistance, while the microhardness of laser remelting coatings increase obviously with the increase of laser currents. The corrosion resistance of laser remelting coatings is improved extensively due to the amorphous matrix and embedded nanocrystals, which popularizes the applications of amorphous coatings to a large extent.

Abstract: Supersonic Particles Bombarding (SSPB) can introduce severe plastic deformation on the surface of metallic materials, and nanostructured surface layer can be fabricated on the materails. So SSPB is a promosing technology which can be applied in industry. Main parameters of SSPB were optimized by orthogonal design, and their effect on the weight loss of the SSPB treated sample was analysed. Optimized parameters were obtained after the orthogonal experiments.

Abstract: In this work, polyurethane coating on the fabrics is studied in the Basecoater 200. The structure and morphology of coated fabrics were investigated using SEM and soaking test in the cured coated samples. Coating thicknesses, surface friction coefficient and surface roughness variation of the samples were measured using the surface tester of the KESF. Results showed that uniform and cross linking degree of the surface layer of coated samples have close relevant with coat processing. The performance quality of end products can be achieved by optimization of process variables, including coating speed, coating solution, and cure temperature and fabric matrixes during fabric coating processing.

Abstract: The preparation of melt-blown filtration materials was studied in this paper. The effects of collection distance, screw speed, air temperature on web structure and properties were discussed, and moreover, fiber diameter, thickness, surface density, pore size, air permeability and breaking force of PP nonwoven fabrics were characterized in this paper.

Abstract: In this paper, modal analysis of ball end mills is modeled by finite element to work out natural frequency and chatter model in tooling system and to calculate the limit curve of stability in single degree freedom system. The effect of cutter flute length and cutter tooth number on maching stability area is also discussed. The results of research show that steady critical cutting depth of milling system declines while the cutter flute length increases, but the trend is not linear, which shows increase partly. An engineering optimization design is made on milling cutter geometrical parameters based on this conclusion.

Abstract: In order to analysis the nonlinear characteristics of vibration signal in the milling chatter process, this article uses Lyapunov Exponent and Approximate Entropy to analysis vibration signal of stable milling, vibration signal of chatter development and vibration signal of chatter in varied cutting-depth milling process. Plot the relationship curves of milling parameters with Lyapunov Exponent and Approximate Entropy respectively. The results showed that vibration signal had strong chaos characteristics when the milling chatter developed and occurred, and chaos characteristics of the vibration signal can be regarded as an effective method to identify the development and occurrence of chatter, and it also has guiding function for choosing milling parameter.

Abstract: Based on partial conjugation principle, revised machine tool adjustment parameters and processing parameters which can make big gear and small gear be in points conjugation meshing progress are obtained after the cutting tooth plan and rough gear parameters of spiral bevel gears in a heavy vehicle main driving system were determined. Ideal gear contact spots are gained by gear contact area rolling experiment, which show that calculation theory and methods above-described are practicable and effective for improving meshing quality of spiral bevel gears in heavy vehicle main driving system.

Abstract: In the application of the TOFD inspection method, the analysis of test results is the focus and aporia of the study. TOFD image analysis include: analysis of defect size, location analysis and defect map features. In order to increase people's understanding of the TOFD technique, given butt joint welds TOFD and RT detect. The paper introduces basic process of defect using the TOFD method, describes method of quantitative orientation of the defect in detail, analyzes the localization and quantification of defects in detection. Determine the qualitative of defects by Ray photographs and analyze the characteristics of the defects of this nature in the TOFD image.

Abstract: Laser processing ceramic materials is a new application of laser technique. This paper presents the study of laser processing parameters of glaze cladding. It found out that the parameters of laser processing affected the morphology of glaze cladding significantly. Within the experimental conditions, rise of output power or drop of processing speed can increase the depth of melted zone and the width of glaze cladding, vice versa.