共查询到19条相似文献,搜索用时 187 毫秒
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提高SLS覆膜砂铸型(芯)强度的措施 总被引:6,自引:2,他引:4
分析了影响覆膜砂铸型(芯)烧结强度的因素,详细地讨论了提高选择性激光烧结(SLS)覆膜砂铸型(芯)烧结强度的各种措施。从烧结方式上探讨了如何既提高SLS制件强度、又保证制件的成形速度和精度的问题。 相似文献
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研究激光选区烧结(SLS)实现快速精密铸的方法和工艺,提出采用激光烧结快速成形直接制作精密铸造壳型的方法,通过使用合适的粉末材料,并与传统的砂箱铸造相结合,可使铸造过程大大简化,铸造件质量也易于保证。 相似文献
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液态Ni-Fe合金的超过冷与热力学性质 总被引:3,自引:0,他引:3
采用熔融玻璃净化法使液态Ni-10%Fe和Ni-35%Fe合金过冷度分别达到371(0.90△T_h)和343K(0.91△T_h).实验测得其超过冷临界过冷度△Th分别为413和376K.根据超过冷的定义导出一种测定深过冷熔体平均比热容的方法,从而得到两种深过冷合金的比热容为41.0和40.7J/(mol·K).据此对快速凝固过程中的焓变△H_(LS),熵变△S_(LS),相变驱动力△G_(LS)以及晶体形核率Ⅰ进行了理论计算.发现尽管过冷度超过了0.2T_L,液态合金仍然发生异质形核. 相似文献
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许思达 《锻压装备与制造技术》1999,(1)
快速成形(简称RP)技术始于10年前,其中,立体成形(简称SLA)技术得到了最广泛的应用。SLA技术的基本原理是将计算机控制的激光束扫描一个盛有光敏树脂的溶液槽表面,使表面依照所需形状硬化,然后工作台下降一个高度(0.01mm),使液态树脂覆盖在硬化... 相似文献
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《中国铸造》2004,(2)
1 .Introduction Based on the parameters and cross-section's information from a CAD model, the selected laser sintering (SLS) uses a laser beam to sinter selectively powdered solid materials (plastic, wax, ceramic, metal, etc.), and the solidified material is built up layer by layer to formthepart needed} As there are still some problems in material and technology, it is difficulty to sinter or produce directly 相似文献
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Selective laser sintering (SLS), as a kind of additive manufacturing technology, which uses a laser beam to scan and heat powder material layer by layer to form parts (models), is widely used in the field of casting, mainly for preparing casting coated sand cores, investment casting patterns, etc. The SLS technique facilitates rapid casting and shortens the casting production periods by eliminating mold preparation. In this study, we reached conclusions for the basic principles and characteristics of SLS methods, and focused on the research status, key technology and development trend of SLS in the fields of forming coated sand-casting molds and investment casting patterns. 相似文献
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基于覆膜砂激光快速成型的无模快速铸造方法研究 总被引:2,自引:0,他引:2
用激光扫描覆膜砂,当激光功率足够大时,覆膜砂的树脂膜会发生过烧和炭化而失去粘结作用。利用此特点,本文提出一种以激光扫描零件轮廓边界为基础的直接生成铸型的方法:用大功率激光逐层扫描出零件各层的轮廓边,相当于在覆膜砂上扫描出目标模型与砂型的分割面,对砂箱整体进行加热固化后,可得到三维的目标模型和砂型。本文给出了由此方法实现快速铸造的工艺方案,并进一步实现了金属零件的快速铸造。该方法有别于SLS工艺的面域扫描,具有分层简单、成型时间短、速度快、成型件强度高的特点,实现了铸造零件CAD/CAM的计算机集成制造,对缩短新产品开发周期和降低成本具有重要的意义。 相似文献
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1 INTRODUCTIONItisanimportantdevelopingdirectiontoproducethin wallaluminumalloycastingbyusingresinsandmold(core) ,whichdemandsthattheresinsandhasappropriatehigh temperaturestrengthandlowerhigh temperatureretainedcompressionstrength .Inrecentyears ,anumbero… 相似文献
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Yu-sheng Shi Jin-liang Zhang Shi-feng Wen Bo Song Chun-ze Yan Qing-song Wei Jia-min Wu Ya-jun Yin Jian-xin Zhou Rui Chen Wei Zhou He-ping Jia Huan-qing Yang Hai Nan 《中国铸造》2021,18(4):286-295
Additive manufacturing is expected to transform and upgrade the traditional foundry industry to realize the integrated manufacturing and rapid and low-cost development of high-performance components with complex shapes. The additive manufacturing technology commonly applied in casting mold preparation (fusible molds, sand molds/cores and ceramic cores) mainly includes selective laser sintering (SLS) and binder injection three-dimensional printing (3DP). In this work, the research status of SLS/3DP-casting processes on material preparation, equipment development, process optimization, simulation and application cases in aerospace, automotive and other fields were elaborated. Finally, the developing trends of the additive manufacturing technology in the future of foundry field are introduced, including multi-material sand molds (metal core included), ceramic core-shell integration and die-casting dies with conformal cooling runners. 相似文献
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研究了三维喷墨打印(3DP)工艺在中大型冲压模铸钢件制造生产中的应用。测试了打印砂型的抗拉强度、透气性、发气量等性能,并基于3DP工艺设计了砂型。结果表明,3DP打印砂型的抗拉强度可达1.70MPa,透气性大于400,最大发气量为14.6mL/g,均可满足合金钢铸造的使用要求。3DP打印砂型(芯)具有无需模具、可以采用砂型和砂芯整体化工艺等特点,提高了铸件的精度。通过对3DP砂型设计,并通过特殊工艺方法,解决了打印砂型的铸字清晰度的问题。 相似文献