共查询到20条相似文献,搜索用时 125 毫秒
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介绍了提高铝合金耐磨抗蚀性能的表面强化技术,叙述了热喷涂技术、表面镀覆技术、表面合金化、高能表面改性和复合表面强化技术的研究现状及其应用效果,展望了未来铝合金表面强化技术研究的发展趋势。 相似文献
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对裸铝表面、粗糙表面和腐蚀表面结霜/融霜过程进行了试验研究,对不同时期霜晶生长过程进行了观测。结果表明:在一次结霜过程中,裸铝表面的霜晶生长高度明显高于腐蚀表面和粗糙表面。在二次结霜过程中,裸铝表面由于融霜液滴的局部聚集,导致霜晶高度明显增加;腐蚀表面由于具有亲水性质表现出较好的抑霜性能;粗糙表面上霜晶颗粒细小,沿平面方向分布均匀,在表面形成了一次质密且较为坚硬的"冰面"。2次融霜过程中,腐蚀表面的平均融霜时间比粗糙表面减少了38.2%,可见具有亲水性质的腐蚀表面具有较好的抑霜性能。 相似文献
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当前制备的超疏水表面耐磨性能普遍较差,因而其在各领域的应用受到限制。研究表明微纳结构和低表面能是实现功能表面超疏水性能的关键因素,因此,首先基于超疏水表面作用机制,对超疏水表面织构进行了归纳,旨在通过优化表面织构来解决微纳结构易磨损难题;然后对超疏水表面加工技术进行了梳理总结,从成本和效率两个方面分析了降低表面能的措施,为拓展超疏水表面加工体系提供思路;进而详细总结了超疏水表面耐磨性的分析手段,并阐述了提高超疏水表面耐磨性的方法;最后,展望了耐磨性超疏水表面的未来发展前景,以期推动超疏水表面在工程中的大规模应用。 相似文献
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粗糙表面在自然界普遍存在。在研究表界面现象时,粗糙表面往往是重要的输入信息。实际测量和数值仿真是获取粗糙表面的两种常用方法。与实际测量相比,数值仿真无需昂贵的测量设备和大量机时,即可根据给定的表面特征信息高效地批量生成粗糙表面。目前,表面仿真已有近五十年的发展历史,基于不同表面形貌特征形成了采用多种表面特征参数的多种仿真方法,在摩擦学研究中应用广泛。梳理和总结表面仿真方法利于方法的高效、准确应用以及进一步发展。考虑到表面仿真方法与表面形貌特征及其表征参数密切相关,为了系统全面地综述表面仿真方法,首先介绍与表面仿真相关的形貌特征表征方法及特征参数。随后,以不同特征为线索对相应的表面仿真方法的原理、算法、优缺点进行梳理,初步提出了方法选用建议,并整理了其在摩擦学研究中的典型应用,最后展望了未来粗糙表面仿真的可能研究方向。 相似文献
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总结讨论了国内外在陶瓷磨削表面/亚表面损伤方面所作的研究及其所取得的成果;讨论了表面/亚表面裂纹和残余应力产生的原因及扩展机理;探讨了控制陶瓷磨削表面/亚表面损伤的途径;指出了当前研究所存在的问题及今后需要努力地方向。 相似文献
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新的先进制造模式知识表示方法 总被引:8,自引:0,他引:8
针对解决知识化制造系统的自重构问题,提出一种新的基于知识网和Agent 网的先进制造模式知识表示方法。首先给出知识网的定义及与Agent 网的关系,定义知识网多重集及其与知识网的映射关系和知识网多重集的并、交、差等运算,其次给出知识网多重集的并、交、差及其混合运算性质,研究多重集运算性质的物理意义,比较多重集和经典集合在运算性质方面的异同点,定义知识网的完备性和两个知识网之间的割集及其多重割集。在此基础上,研究基于关系数据库的知识网实现和知识网推理机问题。最后通过知识化制造系统自重构的两个例子介绍基于知识网和Agent 网的自重构方法,证实其有效性。 相似文献
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Wei Li Beizhi Li Jianguo Yang 《The International Journal of Advanced Manufacturing Technology》2017,91(9-12):3135-3143
The influences of tool setting errors on skiving accuracy are discussed in this paper. Firstly, a method for the calculation of error-free cutting edge of skiving cutter is proposed. Based on the theories of cutter enveloping gear, the gear profile deviations, which are affected by the tool position and orientation errors in skiving, are analyzed. Results show that the profile deviations are insensitive to this kind of setting error of the cutter. Then, the effects of tool eccentricity error on skiving accuracy are analyzed. Results show that the waves on the tooth flanks, which are caused by the tool eccentricity error, have obvious influences on the helix deviations and the profile deviations of the workpiece. The waves on the tooth flanks are periodic ones and can be obviously affected by the number of teeth of the cutter. 相似文献
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Youngjae Shin Jonghak Yun Kyeongyoun Seong Jaeho Kim Sunghwang Kang 《Journal of Mechanical Science and Technology》2006,20(4):467-472
A study of the natural vibrations of beam resting on elastic foundation with finite number of transverse open cracks is presented.
Frequency equations are derived for beams with different end restraints. Euler-Bernoulli beam on Winkler foundation and Euler-Bernoulli
beam on Pasternak foundation are investigated. The cracks are modeled by massless substitute spring. The effects of the crack
location, size and its number and the foundation constants, on the natural frequencies of the beam, are investigated. 相似文献
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转子系统在线动平衡综述及展望 总被引:15,自引:1,他引:14
介绍了动平衡理论及技术的发展,对各种在线自动平衡装置进行分类,并着重综述了这些装置的优缺点,指出在线动平衡研究今后需要解决的问题。 相似文献
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Ilmar Ferreira Santos 《摩擦学汇刊》2013,56(3):700-706
This paper gives a theoretical and experimental contribution to the problem of active modification of the dynamic coefficients of tilting-pad journal bearings, aiming to increase the damping and stability of rotating systems. The theoretical studies for the calculation of the bearing coefficients are based on the fluid dynamics, specifically on the Reynolds equation, on the dynamics of multibody systems and on some concepts of the hydraulics. The experiments are carried out by means of a test rig specially designed for this investigation. The four pads of such a bearing are mounted on four flexible hydraulic chambers which are connected to a proportional valve. The chamber pressures are changed by means of the proportional valve, resulting in a displacement of the pads and a modification of the bearing gap. By changing the gap, one can adjust the dynamic coefficients of the bearing. With help of an experimental procedure for identifying the bearing coefficients, theoretical and experimental results are compared and discussed. The advantages and the limitation of such hydrodynamic bearings in their controllable form are evaluated with regard to application on the high-speed machines. 相似文献
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L. A. Andryushchenko B. V. Grinev V. A. Tarasov 《Instruments and Experimental Techniques》2011,54(5):603-631
The influence of the state of the surfaces of scintillators, which are produced on the basis of alkali halide, oxide, and
semiconductor crystals and treated by different methods, are considered on their performance characteristics. Data on new-generation
abrasive materials are presented. The prospects for the further development of processes used to treat inorganic crystalline
scintillation elements are outlined. 相似文献