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861.
Feedrate optimization and tool profile modification for the high-efficiency ball-end milling process 总被引:3,自引:2,他引:3
Jenq-Shyong By Chen Yung-Kuo Huang Mao-Son Chen 《International Journal of Machine Tools and Manufacture》2005,45(9):1070-1076
Trend in die/mold machining is to produce highly quailed surface using the high-speed hard machining with the ball-end cutter. The ball-end milling is, however, less efficiency than the flat end milling. It is important to optimize the feedrate that gives the maximum material removal rate constrained by an allowable surface roughness. The state-of-art of the CBN ball-end cutter technology allows increasing the tooth feed for high-speed and high-efficiency machining. However, because the spherical shape of the cutter can result in the scallop-liked cusps on the machined surface, the surface roughness consideration makes a feedrate limitation to the CBN cutter. In this paper, the optimization of the feedrate by considering the generated-scallop effect of the ball-end cutter has been studied. It was found that the tooth feed must be kept within one third of the path pick in order to keep the feed-interval scallop height not over the path-interval scallop height. Therefore, the potential capability of the CBN cutter for the larger tooth feed (i.e. high efficient) machining can not be fully exploited. It was found a notch-cut on the center of the ball-end cutter reduced the feed-interval cusp height, thus allowing an increased feedrate of more than 50% compared with the standard ball-end cutter. If the parameters of the notch-cut profile can be optimized, it is believed that the feedrate can be further increased. 相似文献
862.
863.
介绍了国外超细纤维人工皮革的产销与应用情况.追溯了国际上这一领域最新技术的进展.通过对国内未来几年市场需求的分析与预测,提出了应在高起点上发展我国人工皮革的思路。 相似文献
864.
合成气制二甲醚的研究进展 总被引:11,自引:1,他引:11
简要介绍了合成气制二甲醚的原理,工艺流程,双功能催化剂以及近年来的发展状况。 相似文献
865.
Ji-Er Huang 《Carbon》2003,41(14):2731-2736
Single-walled carbon nanotube (SWNT)/polyaniline (PANI) composite films with good uniformity and dispersion were prepared by electrochemical polymerization of aniline containing well-dissolved SWNTs. The results of atomic force microscopy (AFM) and UV-Vis adsorption spectroscopy show that aniline can be used to solubilize SWNTs via formation of donor-acceptor complexes. The electrochemical deposition of SWNT-aniline solutions have been investigated by cyclic voltammetry. The results show that SWNT-based aniline solutions exhibit a drastic increase in peak current within the potential scanning region. The doping effect of SWNTs on PANI films was investigated by electrochemistry and FTIR spectroscopy. The results indicate that the enhanced electroactivity and conductivity of the SWNT/PANI composite films may be due to the strong interaction between SWNTs and PANI, which facilitates the effective degree of electron delocalization. 相似文献
866.
Functionalized carbon nanotubes: properties and applications 总被引:2,自引:0,他引:2
Carbon nanotubes can be functionalized via amidation and esterification of the nanotube-bound carboxylic acids. The solubility of these functionalized carbon nanotubes makes it possible to characterize and study the properties of carbon nanotubes using solution-based techniques. Representative results concerning the solubility, dispersion, defunctionalization, and optical properties of the functionalized carbon nanotubes are presented. Several examples for the use of functionalized carbon nanotubes in the fabrication of polymeric carbon nanocomposites, the probing of nanotube-molecule interactions, and the conjugation with biological species are highlighted and discussed. 相似文献
867.
868.
HN型催化剂催化α——蒎烯制苎烯的初步研究 总被引:2,自引:0,他引:2
本文用HN型催化剂低温催化α-蒎烯异构化制苎烯,考察了反应温度、反应时间、催化剂种类对反应结果的影响。实验结果表明在70℃、反应4h以上,苎烯的选择性仍保持在35%以上。 相似文献
869.
870.
A new method of preparing CuO solar selective absorbing coating for medium temperature is presented. After pretreatment, brass
was overlaid with CuO by chemical plating. The effects of reactant concentration, reaction temperature and reaction time on
the absorptivity of CuO coating were investigated. The optimized condition of preparing CuO coating was obtained. The CuO
coating was analyzed with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). In order to prolong
the period of use, the CuO coating was protected by TiO2. The experiment shows that the TiO2/CuO coating is more heat-resistant, acid-resistant, and wear resistant than CuO coating, without losing absorptivity markedly.
The TiO2 coating can reduce emissivity and protect the CuO coating.
Translated from Journal of Tianjin University, 2006, 39(12): 1485–1489 [译自: 天津大学学报] 相似文献