共查询到20条相似文献,搜索用时 140 毫秒
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介绍了热流道成形技术的优点,分析了热流道技术在该文金属粉末注射模具实例中的应用,研究了热流道技术在该文金属粉末注射模具实例中应用的结构特点。设计了金属粉末注射成形模具的热流道喷嘴,阐述了热流道技术的优点,展望了热流道技术在粉末注射成形技术的发展前景。 相似文献
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热流道注射模热流道板的设计 总被引:3,自引:0,他引:3
介绍了避免或减小热流道模具中热流道板加热后膨胀导致喷嘴的中心线产生的偏移的几种补偿结构,列举了3种热流道板加热功率的计算方法,可为热流道模具的设计提供参考。 相似文献
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"热流道"是在注射模中使用的,将融化的塑料注入到模具的型腔中加热组件集合的一种技术,在上个世纪70年代兴起,80年代中期热流道技术已经被广泛应用于欧美日等发达国家的注射模行业中,中国大陆地区直到90年代才开始逐渐引入热流道进行注射模的生产。进入新世纪后,中国的热流道制造企业犹如雨后春笋般蓬勃发展,在短短十多年的时间里,兴起了数以千计的热流道企业,而在这段时间里国外知名的热流道企业也看中了中国市场巨大的商机,而纷纷开始强势入驻到中国市场,热流道在中国的发展迎来了空前的繁荣。作为台资品牌的群佳实业有限公司是一家专业从事热流道系统生产的企业,在国内大型热流道企业中极具代 相似文献
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浅盒形件顺序开模热流道叠层式注射模设计 总被引:2,自引:1,他引:2
介绍了PP盒盖件顺序开模的热流道叠层式模具结构、热喷嘴和热流道板的设计要点 ,利用该热流道叠层式模具一次可成型普通注射成型的2倍制品 ,模具开模可靠、经济。从理论上计算了热流道板的加热功率和热膨胀变形量 ,并采取相应的防涎措施和温度控制系统 相似文献
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热流道注射模中充模力的计算 总被引:2,自引:0,他引:2
就热流道注射模具 ,根据塑件形状不同 ,分析了熔体在等温流动和非等温流动时 ,流经不同位置时的压力损失。推导出了计算充模压力的数学模型。 相似文献
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介绍了扩散焊接技术在热流道模具分流道板和注射模型芯制造中的应用 ,采用该技术 ,可优化型芯结构 ,缩短成型时间 ,提高塑件质量。 相似文献
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J. M. Frederiksen 《工业材料与腐蚀》2009,60(8):597-601
This paper stresses the need for focussing on a better understanding of the term ‘chloride threshold value’ for initiating reinforcement corrosion in concrete structures. It also focuses on the need for more precise values for modelling chloride ingress and for decision making in repair projects and finally on the need for a reliable internationally accepted test method for measuring the chloride threshold value. As a consequence no test results are presented. A provisional formula for design purposes and a test setup for testing the property are reintroduced. 相似文献
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Ti-6Al-2Sn-4Zr-2Mo titanium alloy is a candidate material for multiwall thermal protection system concepts for advanced space transportation system vehicles. The total oxidation kinetics for this alloy, exposed to laboratory air in the 593–760°C range, were monitored by thermogravimetric analysis. The oxide thickness was measured by microscopy and the substrate contamination was estimated from microhardness measurements. Tensile elongation was determined for selected foil specimens after exposure to simulated space shuttle reentry conditions. The variation of total weight gain with time was found to have two distinct parabolic stages separated by a transient region. This transient was due to a process which involved an increase in the parabolic growth rate constant for the oxide and a simultaneous increase in oxygen solubility at the oxide metal interface. The time dependent increase in oxygen solubility at the interface was from about 7 at. % in stage 1 to about 18 at. % in stage 2. The diffusion coefficient for oxygen in the alloy was determined as a function of temperature using the difference between the total weight gain in stage 1 and the corresponding weight gain due to oxide growth. A model for the total oxidation kinetics, accounting for the two individual components namely oxide growth and solid solution formation, is proposed. The activation energy for the diffusion of oxygen in the alpha-solid solution is shown to be roughly equal to the activation energy for the degradation of tensile elongation for the alloy in the foil gage condition. 相似文献
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