共查询到20条相似文献,搜索用时 15 毫秒
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Materials Selection for Semisolid Processing 总被引:2,自引:0,他引:2
The mechanical behavior of alloys in the semisolid state is very sensitive to the volume fraction of solid. In this paper, a simple criterion for processability in the semisolid range is introduced, based on the sensitivity of the volume fraction of solid with respect to minor temperature variations. In addition it is proposed that the processability in the semisolid state can be enhanced using microsegregated material. 相似文献
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Designers employ a number of strategies in choosing material and processes. The choice can be based on engineering analysis, identifying candidates that best meet the mechanical, thermal, electrical and economic constraints of the design. It can be based on past experience, accessed through a questionnaire‐based selection engine. And it can be based on analogy, searching for materials that are “like” on or more other materials in particular regards – in color, or transparency, or texture for example. Here we explore the strategies, identifying ways in which they can be deployed. 相似文献
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Jiaxin Chen Youguang Guo Jianguo Zhu 《IEEE transactions on magnetics》2007,43(11):4004-4009
We describe the development of a permanent-magnet (PM) brushless DC motor for driving high-speed embroidery machines by employing advanced design and analysis techniques. In the design of the motor, magnetic field finite-element analyses accurately calculate the key motor parameters such as the air-gap flux, back electromotive force (EMF), and inductance. Using the numerical magnetic field solutions, a modified incremental energy method calculates the self and mutual inductances of the stator windings. A phasor diagram is derived to compute the motor's steady-state characteristics. To predict the dynamic performance and increase the prediction accuracy, a Simulink-based model simulates the motor performance with the real waveforms of applied phase voltage, back EMF, and current. The motor prototype tested with both a dynamometer and a high-speed embroidery machine validated the theoretical calculations. 相似文献
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计算机辅助选材系统EI 总被引:1,自引:0,他引:1
介绍了计算机辅助选材系统,提出了综合选材中的归化和加权方法,给出了综合选材的最优化方程,以达到利用材料数据库和知识库选择最符合要求的材料。 相似文献
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Classical methods for materials selection only poorly account for the need of incorporating time into the design requirements. Corrosion, fatigue, wear and creep are phenomena that can lead to an accumulation of damage with time, ultimately causing failure. The first step in dealing with this is an evaluation of the potential risk for delayed damage followed by a qualitative ranking of the possible candidates. Beyond this point, both quantitative estimates and design rules have to be used to make the appropriate selection. Examples involving corrosion and creep will illustrate the possibility of and the need for under the form of. 相似文献
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面向绿色制造的材料选择研究 总被引:1,自引:0,他引:1
面向绿色制造的材料选择较之传统材料选择是一种全新的理念和思路.研究了材料对外部环境的影响,提出了面向绿色制造的材料选择方法:技术性原则、经济性原则和环境性原则的综合和集成,探讨了绿色材料数据库和知识库、绿色材料生命周期环境影响评估系统等支撑技术,构建了面向绿色制造的材料选择多目标决策模型,以便为材料选择提供理论和技术支持. 相似文献
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催化裂化装置中波纹管材料的选用 总被引:1,自引:1,他引:0
介绍了Alloy80 0H、80 0HT合金和Alloy6 2 5、6 2 5LCF合金的性能特点 ,指出了用于高温、腐蚀工况下的波纹管在使用过程中应注意的问题 相似文献
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简要叙述了苯酚生产过程中介质对调节阀节流件的腐蚀,分析了介质浓度、温度对材料耐蚀性能的影响,通过耐蚀材料的正确选用,提高了调节阀的使用寿命,从而获得较高的性能价格比。 相似文献
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The selection of materials for pressure vessels and chemical plants depends on a number of factors such as operating pressure, operating temperature, operating medium, regulations in force in the country of the plant user concerned and manufacturing possibilities. The essay clearly explains how the above specified factors individually influence the selection of materials. The article also deals with the ranges of application of certain material groups such as unalloyed and low-alloy steels, fine-grained steels, austenitic chromium-nickel steels, unalloyed ferritic chromium steels and other materials. The article closes with remarks on the operational safety of pressure vessels. 相似文献
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军事装备野外封存封套材料选择 总被引:1,自引:0,他引:1
目的研究野外条件下军事装备封存封套材料的选择方法和技术指标,指导封套材料的选择,并提供技术依据。方法依据军事勤务需求确定封套材料的技术指标,依据有关技术检测标准确定封套材料的检测方法,选择典型气候环境条件,并进行为期1年的野外曝晒试验,委托第三方试验检测机构对试验前后封套材料的性能开展技术检测,最终依据检测结果选择满足要求的封套材料。结果经过野外曝晒试验和第三方技术检测,从9种新研的封套材料样品中选出了3种符合技术指标要求的封套材料。结论提出的封套材料选择方法和技术指标合理可行,选出的封套材料性能良好,适合用于军事装备野外封存防护,有利于提高军事装备的完好率。 相似文献
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包装材料的发展与选择 总被引:3,自引:1,他引:2
通过对包装材料的介绍,探讨了包装材料的发展与分类以及包装材料的选择原则。材料作为包装的载体,是体现设计思想的物质基础,在整个包装发展过程中起到了不可忽视的作用。 相似文献
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Lai Xiwei 《功能材料》1998,(2)
在配方确定以后,原料的档次与含杂量对陶瓷PTC过流保护元件的性能有极大的影响。本文通过各种试验、分析与比较,说明只能用高纯、低有害杂质原料,方能做出优质过流保护元件。本文还证实了,国内有的厂家的原料,已达到制备陶瓷PTC过流保护元件的需求。 相似文献
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系统选择钙钛矿型透氧膜材料 总被引:1,自引:0,他引:1
提出了一套系统选择具有高透氧能力、结构稳定性及热化学稳定性的钙钛矿型混合氧离子电子导体透氧膜材料的策略,在此策略指导下开发出了若干新的导体膜材料.采用了标准陶瓷法、络合法等对材料进行了合成,采用色谱法及X射线粉末衍射法分别对其透氧性能与稳定性进行了测定与表征,并将其与几种典型透氧膜材料进行了比较.结果表明此系列新材料确实具有预期的透氧性能与结构和热化学稳定性.典型材料,Ba0.5Sr0.5Co0.8Fe0.2O3-δ导体膜在850℃下透氧量达1.16mL[STP]·cm-2·min-1,并在长达1000多小时的测定中保持稳定的透氧能力. 相似文献
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系统选择钙钛矿型透氧膜材料 总被引:12,自引:2,他引:10
提出了一套系统选择具有高选氧能力、结构稳定性及热化学稳定性的钙钛矿型混合氧离子电子导体透氧膜材料的策略,在此策略指导下开发出了若干新的导体膜材料,采用了标准陶瓷法、络合法等对材料进行了合成,采用色谱法及X射线粉末衍射法分别对其透氧性能与稳定性进行了测定与表征,并将其与几种典型透氧膜材料进行了比较。结果表明此系列材料确实具有预期的透氧性能与结构和热化学稳定性。典型材料,Ba0.5Sr0.5Co0.8Fe0.2O3-δ导体膜在850℃下透氧量达1.16mL[STP],cm^-2.min^-1,并在长达1000多小时的测定中保持稳定的透氧能力。 相似文献