Materials Science Forum Vols. 532-533

Abstract: First, the forward kinematic model, the inverse kinematic model and the error model of a kind of coordinate measuring machine (CMM) using 3-DOF parallel-link mechanism are established based on the spatial mechanics theory and the total differential method, and the error model is verified by computer simulation. Then, the influence of structural parameter errors on probe position errors is systematically considered. This research provides an essential theoretical basis for increasing the measuring accuracy of the parallel-link coordinate measuring machine. It is of particular importance to develop the prototype of the new measuring equipment.

Abstract: Helical structure plays an important role in many fields and the machining quality is important for its applications. In this paper, a kind of functional hollow lightweight metallic micro-helixes based on cells of spirulina was manufactured by bio-limited forming. Then the impurity degree and the un-metallization degree, two important parameters to evaluate the machining quality of the functional micro-helixes in the application to chiral microwave absorbing material were investigated. Numeric models were established and the regularities were researched on how the two parameters are influenced by metallization technology factors. The results showed that the values of these two parameters could be reduced by adjusting the volume of the original deposition solution for 1g filtered wet activated cells, the diluted multiples of the original deposition solution, the temperature of reaction and the time of reaction so as to improve the machining quality.

Abstract: Three kind of diamond circular saw blade with different structure parameters are designed in this paper. Adopted single-factor test, sawing force and vibration are measured by cutting several kinds of strength concrete in different cutting parameters. The analysis to characters of sawing force and vibration helps to find out optimum structure of diamond saw blade with different segment width, more rational sawing parameter and its adaptability to workpiece material.

Abstract: This article discusses the problem about the method for the optimization of cutting parameters. A newly developed computational method which is different from the former was used for the optimization of cutting parameters. This method has its advantages of the controllability of the precision and higher speed when the precision requirement of the system is not very high. It can optimize cutting parameters toward the objectives of maximum production rate, minimum production cost and maximum profit rate.

Abstract: In the present research the thermal properties of phenolic resin 2123-P mix-modified by nano-alumina are investigated. The nano-alumina employed in the research can be classified two kinds, one is treated by 1%wt. silane coupling agent KH-550 relative to the weight of alumina, and the other is commercial alumina untreated. DTA-TG results show the thermal stability and anti-weight loss ability of the mix-modified phenolic resin 2123-P with KH-550 treated alumina are increased relative to those of the pure 2123-P and those of the mix-modified 2123-P with commercial alumina, and the results are to be proved by the constant speed friction and wear tests. It can be observed from SEM that KH-550 treated nano-alumina particles are dispersed equably in phenolic resin.

Abstract: Carbon, aramid and glass fibers are inherently superior to conventional textile fibers in terms of mechanical properties and other characteristics. However, each material has its inherent advantages and disadvantages and it is usually recommended to hybridize them to fully benefit of their high performance in practical applications to many products. This paper is concerned with an air texturing process for hybridization of different reinforcement filament yarns. A normal air texturing machine was selected for process development and modified to suit testing purposes. The modified process for hybridization was introduced mainly in terms of air-jet nozzles employed in experiments. With the proposed air texturing process machine, three types of air-nozzle were applied to the experimental work. Three different filament materials were employed in experiments and they are carbon (CF), aramid (AF), and glass (GF). As matrix materials, polyether-ether (PEEK), polyester (PES), and polypropylene (PP) were selected and experimented. Hybrid yarns produced form the proposed process was evaluated optically in terms of bulkiness, arranging, breaking, and mixing, respectively. The experimental results were also summarized in terms of relationships between applied air pressure and yarn count, and variation in count. As a whole, it was concluded from the experiments that the proposed texturing process could be successfully applied to the practical hybridization of different reinforcement filament yarns. It was also revealed from the experiments that the air pressure in the proposed process is not a significant parameter on the pressing in terms of yarn count.

Abstract: This paper is concerned the breaking elongation properties of Carbon/Aramid-, Carbon/Glass- and Aramid/Glass- matrix hybridized commingling yarns. The hybrid yarns produced by commingling process were investigated in terms of breaking elongation property. In experiments, carbon (CF), aramid (AF), and glass (GF) filament yarns were combined. In this study, selected matrix materials include Polyether-ether-Keeton (PEEK), and polyester (PES), or polypropylene (PP). The volume content of filament in hybrid yarn cross section was maintained at 50% for both reinforced and matrix, ant hybrid yarns count at 600 tex, respectively. The reinforcement to matrix filament combination was selected as 1:1 proportion. The effect of different air pressures and material combinations was investigated in terms of breaking elongation. In experiments, each type of hybrid yarn sample has been tested 20 times at the testing speed of 10mm/min. under 3 bar of yarn clamping pressure. Since breaking elongation is one of most important properties in textile fiber, it was examined closely with reference to the first breaking point of commingling-hybrid yarns. It was concluded from experiments that hybrid yarns with higher breaking elongation and higher tensile strength tend to show better force-elongation relationship. It was also known from experiments that the combination of two reinforcement filament yarns gives always much better results than a single reinforcement filament yarns in terms of elongation property. GF/AF/matrix is shown very much better elongation properties. PP and PES gives higher elongation than PEEK as a matrix material.

Abstract: According to the characteristics of high speed face milling process, the models of the stress field for high speed face milling cutter with two sorts of structure are proposed and established. By means of the finite element analysis of the stress field for high speed face milling cutters, the law of influence of the cutter’s structure, the cutter’s subassemblies and the fixing rake of inserts on the stress field of cutter is acquired under the action of high rotate speed. In this foundation, the model reconstruction and the stress field analysis of the cutter are completed, and the model of evaluation for dynamic cutting performance of high speed face milling cutter is established. The results of high speed face milling experiment and frequency spectrum analysis of dynamic cutting force of the cutter indicate that high speed face milling cutter with the fixing rake of zero degree and less subassemblies takes on better dynamic high speed cutting performance.

Abstract: A method for low resistivity resistor on transparent substrate with laser induced plasma assisted by ablation and laser annealing was described. The diffusion distribution for metallization was measured with XPS. The surface profile was analysed with SEM. The minimum resistivity we got was 0.1
/Sq. It demonstrates that the electronic thin film obtained has a very good conductivity. The most important factors for forming electrically conducting films on the transparent substrate are laser fluence, beam scanning and pulse repetition rate. This technology will be useful in the fabrication of LCD electrode, glass defused resistor and circuit on glass.

Abstract: 35CrMnSiA, is a kind of important engineering materials that used widely in modern manufacturing fields. The machinability of 35CrMnSiA Steel with hardness of HRc40±2 in high speed turning process was studied in this paper. It is concluded that, when high speed turning of this ultra-high strength alloy steel, the chief wear mode of ceramics is the crater on rake faces; the interaction of depth of cut and feed rate is one of statistic significant effects on cutting force; the interaction of cutting velocity of cut and feed rate is one of statistic significant effects on surface roughness Ra; besides, the empirical formula of average cutting temperature, cutting forces, surface roughness Ra, was established.