Applied Mechanics and Materials Vols. 490-491

Abstract: With the development of scroll technology, the requirements of more efficient and more accurate processing method for scroll compressor parts become more urgent. This paper proposes a method to improve the machining effect of scroll compressor. The approach is based on 3-point arc approximation method which divides combined profile of scroll wrap into subparagraph arcs that can be interpolated on CNC System. This approach simplifies the programming process and improves the curve fitting effect. The results indicate that the fitting error is in the predetermined range, and the interpolation points of cutter center track are significantly less than those based on CAD/CAM software. The method presented in this paper is of significance to the NC machining of novel precise scroll profile.

Abstract: Combined with the companies own experience in production, establish the parameter optimization model for turning, the parameter optimization software have been developed using the MIT GALib genetic algorithm library in VC6.0 environment. The software can achieve the optimization of cutting parameters, improve the optimization of efficiency, expand the range of applications of cutting database, lay a good foundation for the integration with cutting database and enterprise itself CAPP.

Abstract: In order to obtain the maximum amounts of amino functional groups with low temperature ammonia plasma surface treatment on PAN-based carbon fiber, the influence of processing temperature and time were researched in this paper. By using X-ray photoelectron spectroscopy (XPS) method, the-NH₂(-NH)/ C-C atomic ratio of untreated and treated fiber was analyzed. Results show that processing temperature is a key factor as intensity of the N1s peak increases gradually while processing temperature improves, furthermore, when temperature is 175°C, the most intensity of the N1s peak is obtained. Low temperature ammonia plasma surface treatment method has given a new approach to surface functionalized treatment of carbon fiber.

Abstract: Low cost, short cycle and high quality are the goals of the automobile manufacturing. The auto die is one of the key equipments in automobile industry. For the die manufacturing process is very complicated the trial-and-error method is still used in the tryout process especially the die face tryout. The computer aided engineering becomes more and more important for the new die development. In this paper the precise die face design process based on the blank drawing and die structure simulation for automobile die is studied in detail. The precise die face is generated by the cloud of simulation nodes distribution. The industrial application shows that the precise die face design method based on point cloud generation for automobile die is an efficient way for decreasing the die manufacturing cycle and an accurate method for die tryout process.

Abstract: Green high-speed cutting is one of the main development directions of advanced processing technology.The defects of the traditional cooling and lubrication conditions and the deficiencies of external MQL (Minimum Quantity Lubrication) were analyzed in this paper. A new way of cooling and lubrication named internal MQL was highlighted, and an internal MQL system applied to turning was researched and designed. By high-speed turning of bearing steel GCr15 under different cooling lubrication conditions as dry turning, external and internal MQL, the comparative study of cutting force and surface roughness was carried out systematically. The results showed that the internal MQL has a comparative advantage, showing a good application prospect.

Abstract: The carbon dioxide corrosion on N80 steel was evaluated under the gas phase and the liquid phase. With the test temperature improved, the corrosion rate increases. Under the condition of gas phase, the corrosion peak is 0.2942mm/a when the temperature is 110°C and pressure is 24 MPa. Under the condition of liquid phase, the corrosion peak is 26.5325mm/a when the temperature is 50°C and pressure is 24 MPa. With the increase of CO₂ partial pressure, the corrosion rate of N80 steel was falling. Microscopic analysis shows that the corrosion products of CO₂ on N80 steel have a large white flocculent compounds and the corrosion surface have a lot of cracks and holes.

Abstract: In this paper, the method of resistance spot welding with cover plate was proposed to weld the materials combination of the metal with high resistance and the metal with low resistance, such as steel/aluminum, titanium/aluminum, titanium/magnesium, and steel/magnesium; and the technique of resistance spot welding with insert sheet was proposed to weld dissimilar materials with low resistance and to weld dissimilar materials with high resistance.

Abstract: Herein, we report the synthesis of PbS Quantum Dots (QDs) with oleic acid as surfactant molecules by non coordinating solvent route. The particles are having better size tunability by varying temperature and time of reaction. These quantum dots are characterized by optical absorption, photoluminescence and transmission electron microscopy. The resulting colloids are highly stable, extremely small size, spherical in shape, monodisperse and strong band emission. The estimated particles sizes are in the range of 2 to 6 nm. The present method of synthesis of PbS quantum dots can be used to fabricate low cost electronic devices.

Abstract: In this paper, we concern with the nonlinear wave equations with nonlinear damping and source terms. By using the potential well method, we obtain a result for the global existence and asymptotic behavior of the solutions.

Abstract: This study focuses on the prediction of complex eigenpairs of modified asymmetric systems. A method, which combines the reduced basis and the projection technique, is presented to predict the eigenpairs of modified asymmetric systems. The reduced basis obtained using the homotopy perturbation technique only requires the eigensolution of interest such that the modal truncation problem can be avoided. More importantly, the method can be carried out without using the left eigenvectors. The accuracy of the reduced basis approximation can be improved by introducing the projection technique. A rotor dynamic system is used to illustrate the capacity of predicting the changes of eigensolutions.