Key Engineering Materials Vol. 568

Abstract: Friction and wear of the guideway is an important factor which affects its precision, the parameter which affects friction and wear performance is no single. Among them, surface precision of the guideway has a great influence on the wear. In this paper, Taylor Hobson roughness profilometer is used to measure the guideway specimen according to the principle of statistics, and then the surface topography assessment parameters are obtained. Based on those, the rough surface topography is characterized and statistical models with contact parameters are established. Contact models are analyzed by using simulation software Mat lathe results: the contact parameter values show linear growth trend as the distance decreasing, the values become smaller as the roughness increasing, but the trend increases corresponsive.

Abstract: The casting machine of the shock excitation and rotation comprehensive effect was obtained by the improvement on the basis of the traditional casting technology. Mine manganese steel hammer was cast by the casting machine of the shock excitation and rotation comprehensive effect. The manganese steel hammer was analyzed by the microstructure and wear resistance. The casting mechanism of the casting machine of the shock excitation and rotation comprehensive effect was further discussed. The experiment result showed the cast manganese steel by the shock excitation and rotation method had the advantages of the grain fine and uniform, good wear resistance. Comparing to the traditional technology, the new casting technology could extend the service life of the casting manganese steel.

Abstract: Numerical simulations were used to investigate the influence of various hot filaments and other deposition parameters on substrate temperature field which affects significantly the growth and quality of diamond films by Electron-assisted Chemical Vapor Deposition (EACVD). The results show that the hot-filament parameters have great influence on the magnitude of the substrate temperature, the results also show that the hot-filament number, the substrate swing angle and the distance between the hot-filament and the substrate affect the uniformity of the substrate temperature field deeply. Diamond deposition experiments show that the uniform temperature field for the growth of the diamond can be obtained by optimizing the parameters of the hot-filament and the swing substrate.

Abstract: In this work, a 5-axis machine tool used for dental restorations is designed. In view of the fact that its special characteristics of the applications, the mechanical structure and main part of the machine tool have been designed and chosen with careful calculation. The machine tool is equipped with a high speed electro-spindle driven by computerized velocity and can rotate at a maximum speed of 60,000 rpm, which driving unite is equipped with servomotor and optical grating for its better motion precision control. Meanwhile, by using the motion controller card, the machine is controlled with a closed-loop numerical control system. Based on the theory of multi-body system, and through analyzing the matrix of the position transformation and the displacement transformation, a model for positioning errors is put forth for error compensation in programming way. The grinding programs enable exact copies of the object to be fabricated. The satisfactory results show this machine tool has excellent performances.

Abstract: The manufacture equipment is the key technology in using crop stalks for making biomass fuel which is an effective means of solving the current stalk misconduct processing, improving energy efficiency and preserving the ecological environment. A structure of the molding equipment which is capable of making crop stalks into biomass fuel is designed and orthogonal tested. The hydraulic system and electrical control system of the equipment are also designed. Simulation test of the hydraulic system and programming of the control circuit are implemented. The analyses of the each designed systems of the modeling equipment indicated that the main motor is reasonably chosen, the hydraulic system can meet the design requirements, and the electrical control circuit is capable of being conveniently and efficiently controlled.

Abstract: An acoustic emission (AE) monitoring system has been developed for micro cracks of hull plate, which has a human-machine interface (HMI) designed by Labview, with functions of signal acquisition, storage and replay, key parameters extraction. With the powerful signal processing capabilities of MATLAB, defects can be rapidly and accurately located.

Abstract: The models of finite element analysis are established reasonably after combining the principle of gear engagement, contact mechanics, and finite element concept and method. Simulations are made for the meshing process of the internal gear pairs with few teeth difference using finite element method. Tooth contact area, contact position, and the distribution principles of contact stress along the direction of tooth depth are studied. The main effect factors on the maximum contact stress are analyzed. It is found out that the effect of cusp contact along the tooth profiles may be generated in the meshing process of the internal gear pairs with few teeth difference. The complexity of multi-pair teeth meshing effect during the meshing process is pointed out.

Abstract: Metal milling processing principle and the elastic-plastic deformation theory were combined in this paper. The mathematical model of milling force and residual stress in the NC milling process was deduced by the theory. By the obtained mathematical model, could further analyze the effect of milling force on the residual stress and then obtain the law of milling force to milling deformation. This proved the strong a theoretic guarantee for controlling the machining deformation.

Abstract: Support is not load bearing components, but also carrier of other component. To reduce the valid load, mass of the support should be low down under the condition of enough stiffness and strength. Topology optimization is employed here to solve the problem. The finite model must be built up according to the basic structure of analysis object in topology optimization. The supports are typical box-style part with thin-wall. Thus, solid model is adopted in ANSYS, and the element shell93 is employed here. Definition of optimization function based on linear-static analysis was employed here. Take maximum flexibility as the constrain conditions of the structure. And the optimality criterion (OC) method was adapted to the problem due to it is suitable for the problem which target is volume. Define the base plate, face and back of the support as the topology area separately. Main part of support is optimization with the variable density method. The results before and after the optimization are compared. When the topology form is unknown, the best topology relation of the structure in the initiate design stage of the whole product has very important meanings.

Abstract: The method of contour path planning in Pattenless casting manufacturing (PCM) technique not only determines whether the modeling process can be normal and smooth, but also have a great impact on the forming accuracy and efficiency. The requirements of the different planning algorithm is reasonable and perfect.The algorithm directly impact on the efficiency of data processing, and the generating results also directly determines the forming efficiency and forming quality. In the paper, the suitable process planning for PCM technique is realized.