Advanced Materials Research Vols. 538-541

Abstract: The influences of different preheating temperature of mold and treatment temperature on solidified structure of LC9 alloy were studied by low-power ultrasonic vibration melt-treatment. The results show that grain of LC9 alloy can be refined greatly by low-power ultrasonic vibration melt-treatment. The dendrite growth is restrained and the microstructure is changed from larger dendrite grains to dominant fine none-dendritic and globular grains. With the decrease of preheating temperature of mold, grain size decreases. The efficiency of grain refinement is better at low preheating temperature. With the increase of ultrasonic vibration temperature, grain size decreases firstly, then increases, and the turning point is 660 °C. At 640 °C, grain size of the alloy with US vibration treatment changes slightly compared with non US-treated alloy.

Abstract: At present, bimetal tube has been used wildly in industry and there are many methods for preparation these kinds of tubes. In consideration of deficiencies of available methods, a new technique of bimetal tube preparation was presented in this paper. With appropriate design and manufacture of facility and design of experiment, copper clad steel tube was prepared. Feasibility and practicability of this process was verified by conclusion of research. At last, the following study was discussed.

Abstract: The paper introduces an improvement in technology of processing piston of air conditioning compressor in automobile, and methods of designing, manufacturing, and testing a special machine by which the processing quality and efficiency are enhanced.

Abstract: In order to control the wire diameter stability for pitch carbon fiber melt-spinning effectively, this can affect the performance of carbon fiber. This paper presents an asphalt carbon fiber melt-spinning wire diameter stabilization method based on radial basis function neural network. Firstly, the relation model that pitch carbon fiber melt-spinning wire diameter, spinning temperature, spinning pressure and spinning roller speed was established through measured data based on radial basis function neural network. Then control the spinning temperature, pressure and spinning rollers speed coordination changes to ensure the stability of spinning wire diameter in spinning process. Finally, we apply this method to our laboratory measured data and compared with existing experience formula. The result shows that the method is feasible and effective

Abstract: This paper makes a study of processing methods of several types of fallen leaves, and exploration of ways of collecting, storing, drying, crushing, and screening of leaves, involving a study of the rate of water loss of leaves in the drying process at different temperatures, and a comparison of crushers to be chosen in the crushing process of the leaves so as to provide a reasonable basis for the development and application of the leaves in the field of building materials.

Abstract: The test bed for micron paring machining is a kind of Computer numerical control (CNC) carpentry test beds. Movement of machine is controlled automatically according to processing instructions, machining of different raw materials can be realized by simply changing the processing instruction program. The test bed’s precision and its persistence are mainly guaranteed by the lathe bed, and have an air clamping device and its feeding mechanism includes a stepper motor for CNC feeding. At the end of the thesis, the conclusion of experiment presents widths of micron parings machined by cutting lengthways along the grain fall between 50~150 µm. With further analysis, around 72% of the parings are 60~100 µm thick, around 75% are 5~8 mm wide, around 78% are 65~75 mm long. The results show micron parings machined by the specialised test bed meet the design requirements for micron parings.

Abstract: In this paper, it is analyzes process parameters’ influence on the chip deformation, tool life, machined surface quality and the stability of cutting systems in high speed machining. It provides important reference of the choice of cutting parameters for high-speed machining user.

Abstract: Considering the tribological characteristics of the micro-cutting, an approach that divided the micro-cutting area into four parts based on the contact stress and speed was proposed to the friction performance research. Friction tests under different conditions were carried out on a UMT3 tribometer and a special tribometer assembled based on HAWK TC-150 turning lathe. The morphological analyses of the worn surface were made by optical microscope and scanning electron microscope. The experimental results indicated that different rubbing pairs had different friction properties under different speeds or loads; for stainless steel, high speed steel showed a better friction performance in low speed and load, while cemented carbide has more advantages in high speed or high load. Hence, a suitable choice principle was proposed for the micro-cutting tool material based on the tribological characteristic.

Abstract: The density of bar-cutting wire reflects the intensity of cutting material, in order to evaluate the influence of the cutting material on the formation and hitting probabilities of MEFP, numerical simulations of the forming process of MEFP passing through the cutting bar with different material like aluminum alloy, steel, copper and tungsten are carried out in Lagrange method of LS-DYNA. Then the influence of different cutting material on MEFP’s damage efficiency is analyzed based on the damage index of divergence angle. The results indicate that the cutting material has an obvious influence on the formation of MEFP, and the greater density of cutting material is, the better influence to the formation will be. Therefore, the shorter cutting time is, the better damage efficiency of MEFP will be.

Abstract: Triangulating the point cloud get STL model, a planar spiral line can obtain by offset the STL mode. Along the Z axis projecting towards the Equidistant surface of STL model will get a spatial spiral line, it can be used in numerical control high speed machining.