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通过分子动力学方法(MD),在Osetsky模型和Malerba势能基础上,沿[111]方向插入一层半原子面形成位错;在模型中分别插入沉淀物和空洞,采用共轭梯度法(Conjugate Gradient)进行松弛,模拟BCC铁中刃型位错与沉淀物、空洞相互作用,研究沉淀物和空洞对位错影响机理;将模拟结果与Osetsky的研究数据及连续体模型的结果进行对比和分析。 相似文献
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<正> 正弦波刃型立铣刀是铣削铝、钛等材料的高效刀具。由于这种铣刀设计独特,断屑性能好,在钛、铝等材料的铣削加工中可一次完成工件的粗铣和精铣两道工序,节省了以往采用精铣刀进行的第二道精铣工序。但是,波刃型立铣刀的重磨却非常困难,其主要问题是重磨时使 相似文献
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飞剪剪刃间隙的偏差和大小对能否剪切极薄带钢和剪切带钢的质量影响很大,以某1550 mm酸轧旋转飞剪剪刃间隙调整方法与过程为例,对剪刃间隙调整装置进行优化,剪刃间隙调整后,能够剪切薄0.1 mm的铁皮,能够满足剪切精度要求. 相似文献
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板条状位错型马氏体具有优良的综合机械性能,值得推广应用。阐述了合金的化学成分与马氏体形态及其内部结构的关系及其性能特点。 相似文献
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根据复杂回转刀具的几何特征,建立了回转刀具刃型通用数学模型。设计了复杂回转刀具刃型曲线模型,利用回转刀具刃型通用数学模型推导了复杂刀具刃型曲线方程。基于空间任意点的螺旋运动,建立了多段刃型的连续性模型,并通过了实例验证。 相似文献
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T. Nguyen M. Liu L. C. Zhang 《The International Journal of Advanced Manufacturing Technology》2014,73(1-4):341-352
This paper investigates the cooling effect when using an air jet at sub-zero temperature of ?15 °C in the plunge grinding of a cylindrical component made of high strength steel EN 26. A three-dimensional finite element heat transfer model with a moving heat source was developed to reveal the complexity of the heat transfer mechanism involved. It was found that the use of cold air does not significantly reduce the temperature rise in grinding and that the cooling effectiveness is mainly limited by the following facts: (a) the air jet is difficult to penetrate into the grinding zone, (b) the heat transfer coefficient provided by an air jet is small and (c) cooling is limited by the time which the rotating workpiece surface can be exposed to the jet impingement. The study also showed that the present modelling method can be used as a first tool to assess the feasibility of a new cooling medium for grinding operations. 相似文献
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介绍了一种适用于球阀、蝶阀和旋塞阀的阀杆旋转角度启闭的撑拢式阀门密封结构。此种结构已获得发明专利(专利号:00111674.6)。 相似文献
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V. V. Stulov 《Journal of Machinery Manufacture and Reliability》2016,45(3):266-269
The results of structural calculations for the cooling of a cylindrical crystallizer in a continuous casting machine for steel molds are given. The material for crystallizer walls has been replaced. The novelty of this study has been validated with an invention patent. 相似文献
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The problem of in-plane bending of a single unreinforced mitered joint between two cylindrical shells of equal diameter is analyzed according to thin shell theory. The solution is constructed by the method of matched asymptotic expansions. Formulas for the stress amplification factor and flexibility factor are derived and comparisons are made with available test results. 相似文献
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介绍炼油厂成功运用skf掌上离线状态监测仪和数据管理软件,检测和诊断机泵故障实例,通过典型案例,充分证明了新技术的应用在机泵故障诊断中的重要性。利用先进的诊断技术发现设备早期故障,避免设备损坏事故的发生。 相似文献