Advanced Materials Research Vols. 295-297

Abstract: We analyzed systematically the causes of various defects of water-soluble plastic film by the production process, and comprehensively discussed the corresponding treatments to reduce or eliminate the defects, to offer theoretical basis and practical methods to the quality control in the production of water-soluble plastic film.

Abstract: This paper is based on the design of the boom system of concrete pump car.fatigue strength of the boom system is analysed detailedly after completing a series of work, such as the boom system simulation, static strength , the stability analysis and structural optimization. Analysis shows that the easiest damaged location of the boom system is in the joint of the third boom, that is the place of the maximum stress in static analysis of the boom system.The safety coefficient is 1.393 after finishing fatigue analysis,and the numerical value is still bigger than specified safety coefficient, namely 1.3;the minimum life total amount (cycle) is 323500, which occurs in the third quarter boom, that is the place of the maximum stress in static strength analysis of the boom system; the fatigue strength of the boom system satisfy the requirement.These research work provide reliable reference for the design and improvement of the boom structure.

Abstract: Combining the low power loss technology with SD card, this system is designed, which is convenient for us to obtain the temperature data of the environment and in which the temperature acquisition module and the data receive memory module are included. The temperature acquisition module is responsible for transmitting the acquired valid temperature value into the data receive memory module by wireless, while the data receive memory module mainly stored the received effective data into SD card after being processed. With the wireless temperature acquisition system, it is convenient for us to acquire and record the multi-point temperature values from the environment.

Abstract: Applicable and effective compensation algorithm can improve the precision of rapid prototyping manufacturing. Based on analysis of present compensation algorithms, a point-by-point calculation compensation algorithm is developed in this paper. The rationality of intersection points of segments of compensation contour is checked point by point, and then the unreasonable points are adjusted. The compensation contours can be gotten. The calculation process of point-by-point calculation compensation algorithm is detailed introduced in this paper. The practicality of algorithm is tested and verified by examples.

Abstract: Internal thread processing is an indispensable procedure in manufacture, its processing efficiency and quality become more and more important in modern manufacturing, especially in aerospace and automotive industry. Compared with the traditional process of cut tapping of internal thread, the process of extrusion tapping of internal thread possesses the following advantages: without chip, higher precision, better surface quality, better continuity of metallic, greater efficient, greater strength, longer tool life. This paper firstly introduces the current research status of extrusion tapping of internal thread, elaborates the principle and characteristic of extrusion tapping, analyzes the matal plastic flow law and thread forming characteristic during tapping, then generalizes the influencing law of the key technology on thread forming quality, such as extrusion tap type, lead hole diameter, tapping speed and friction. Furthermore, puts forward some improvement approach to reduce tapping torque and enhance forming quality of internal thread.

Abstract: The purpose of this study is to propose and apply a MEMS-based gas chromatography (GC) device comprising a miniature serpentine column. A 2 m long, 200 μm wide and 250 μm deep column was fabricated using a wet etching process and bonded to a Pyrex cover plate. After the GC column was coated with Carbowax 20M as the stationary phase, the concentrations of benzene, toluene, Ethylbenzene and m-Xylene were successfully detected in the mixed sample. The leakage test and mixed gas separation test achieved a useful separation result for Ethylbenzene-Xylene and Benzene-Toluen mixture at a 17.1 cm/s linear flow rate in a GC chip column.

Abstract: To avoid slag sticking onto the snorkel during CAS-OB ladle refining process, B₂O₃-CaO(mass ratio equals 1:1) and CaF₂-CaO(mass ratio equals 1:1) were respectively employed as modifiers added to decrease the viscosity of ladle slag. The rotary cylinder method was adopted in the viscosity measurements. The results showed that the modifiers could decrease the viscosity of ladle refining slag remarkably. At 1500°C, the viscosity of ladle slag without any modifiers is about 6.0 Pa·s. But by adding more than 10mass% CaO-B₂O₃ or CaO-CaF₂, the slag viscosity at 1500°C could be decreased lower than 1.0 Pa·s. The mechanism of modifiers decreasing the slag viscosity was analyzed.

Abstract: The conventional finite element method (FEM) cannot investigate the size effect on thermal residual stresses induced by the sintering process in micro multilayer ceramic capacitors (MLCCs). In this paper, a FE two-dimensional single layer model is developed for investigation of the effect of the micro scale on prediction of the residual thermal stresses in MLCCs. In this FE single layer model, the strain gradient effect is considered. It is found that with decreasing single layer thickness, the shear stress increases significantly in the ceramic layer near the electrode tip, which might cause cracking of the ceramic layer near the electrode tip. The numerical results also show that the predictions of the thermal residual stresses in MLCCs are strongly dependent on the micro scale. The residual thermal stresses induced by the sintering process exhibit strong size effects and, therefore, the strain gradient effect should be taken into account in the design and evaluation of MLCC devices.

Abstract: According to the quality problems in one gear enterprise, the DMAIC method which is the core application of the six sigma theory is used to improve the quality of the spiral bevel gear, and the quality data is analyzed by using Minitab software. Firstly, the quality problem is defined in accordance with the DMAIC procedures and the main reasons for quality problems in spiral bevel gears are determined. Secondly, measurement systems and process capability are analyzed. Then, we set a specific program for the improvements for the main causes of quality problems. Through the successful implementation of this project, the quality of spiral bevel gears is greatly improved, and the production cost is greatly reduced. The effect is very significant.

Abstract: In order to meet the needs of boundary conditions and eliminate the residual of governing equations, the weighted residuals method is combined with least squares method solve the nonlinear bending problem of symmetrically angle-lay orthotropic laminated composite plate, and the double fifth B-spline is taken as trial function to seek an efficient method for large deflection of plate. The analytical solution of bending problems of symmetrically angle-lay orthotropic laminated composite plate with clamped boundary conditions is obtained by using the weighted residual method. The results from the present method are in good agreement with those derived from other methods, and the present method has the advantages of simple principle, high calculation efficiency and easy to satisfy boundary conditions as well, superiority to finite element method. In addition, the design of computer program is simple and it is easy to be programmed.