共查询到20条相似文献,搜索用时 140 毫秒
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在刚玉粉料中添加蓝晶石,利用原位合成方法制备了氧化铝基复合陶瓷型芯,讨论了蓝晶石含量以及烧结制度对氧化铝基复合型芯几种性能的影响.结果表明:烧结温度对氧化铝基复合陶瓷型芯蠕变性能影响较大,蓝晶石含量变化影响次之;随着蓝晶石含量增加,陶瓷型芯气孔率增加,线收缩率减小,线膨胀系数减小.随着烧结温度增加,陶瓷型芯气孔率减小,线收缩率增加. 相似文献
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采用不同工艺制备了精密铸造用型芯及强度试样,并对型芯的抗弯强度及型芯、铸件合格率进行了研究.研究结果表明,1 100℃下烧结的型芯抗弯强度及型芯的成品率均高于1 050℃烧结型芯的抗弯强度及型芯的成品率.室温下经低温强化型芯的抗弯强度高于“高温+低温”复合强化型芯的抗弯强度,而单独进行高温强化的型芯的抗弯强度最小.在1 350℃下,经高温强化和低温强化型芯的抗弯强度均高于9 MPa.硅溶胶高温强化型芯在1 350℃下的抗弯强度远低于采用硅酸乙酯进行高温强化的型芯.采用硅溶胶高温强化1 100℃烧结出的空心型芯,具有较好的抗弯强度及退让性的组合,而且其成品率较高,同时该工艺可提高铸件的合格率,降低铸件裂纹率. 相似文献
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本文介绍一种新型预制型芯的制作工艺。该预制型芯比陶瓷型芯和尿素型芯成本低,工序短、清理方便、特别适合于大型熔模铸件,提高铸件合格率。 相似文献
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卓育华 《特种铸造及有色合金》1981,(4)
为了使陶瓷型芯具有所希望的性能,除严格控制型芯的成分配比外,还必须严格控制型芯的烧结。 烧结是指在低于陶瓷粉料的熔化温度下,经过物理及化学的变化,而使制品具有一定外形、微观结构、物理和化学性能的多晶聚合体。这种多晶聚合体称为烧结体。根据在烧结体内是否生成液相,一般可分为固相烧结和带有液相的烧结两大类。前者在烧结体中无液相或有极少量液相,而后者液相量多达体积的三分之一,此时烧结温度必然高于瓷料中某一组分或生成物的熔点。而石英玻璃陶瓷型芯属于有极少量液相参与的固相烧结。 相似文献
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粉料粒度对氧化铝基陶瓷型芯材料性能的影响 总被引:3,自引:0,他引:3
研究了精密铸造叶片用氧化铝基复合陶瓷型芯刚玉粉料粒度对型芯物相、形貌、气孔率、抗蠕变性能、脱芯性能的影响.研究结果表明:粉料粒度对Al2O3基复合陶瓷型芯材料的气孔率、线收缩率和高温蠕变性能均有影响.根据实验数据,分析了几种粉料粒度对陶瓷型芯综合性能影响的机理,同时讨论了不同粉料粒度型芯的烧结机理. 相似文献
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焙烧炉炉温均匀性对陶瓷型芯性能的影响 总被引:2,自引:1,他引:1
顾国红 《特种铸造及有色合金》2001,(3):54-55
在制造复杂内腔的气冷涡轮叶片过程中 ,陶瓷型芯的制造是关键工序之一。它的性能和质量将直接影响叶片的合格率。由于叶片气冷方式的复杂化 ,对陶瓷型芯的性能要求越来越高。在实际生产过程中 ,型芯的焙烧过程是决定型芯各种性能的极重要一环 ,其中烧结工艺和焙烧炉的工况将直接影响型芯的焙烧质量。某机种定向空心无余量涡轮叶片生产实践证明 ,炉温均匀性和烧结工艺在陶瓷型芯制造过程中起着非常重要的作用。本文着重研究在规定的焙烧工艺规范下 ,焙烧炉温度场的均匀性对型芯性能的影响。1 试验条件和方法试验采用氧化硅基陶瓷型芯进行试… 相似文献
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Haihua Wu Dichen Li Yiping Tang Bo Sun Dongyang Xu 《Journal of Materials Processing Technology》2009,209(18-19):5886-5891
Injection moulding is accepted as one of the most important methods for shaping complex ceramic cores, which are used to form intricate internal cooling passages of gas turbine blades. But the relatively long lead time and high costs involved in the fabrication of hard tooling render it uneconomical for new products development and low-volume production. In the study, a rapid prototyping process is developed to fabricate complex-shaped alumina-based ceramic core by combining stereolithography (SL) with gelcasting. SL is utilized to fabricate an integral sacrificial resin mold, and gelcasting is utilized to form a wet ceramic core green body through polymerization of aqueous ceramic slurry. The freeze-drying process is adopted to treat the wet green body surrounded by the resin mold, the drying shrinkage is decreased, and the generation of crack can be prevented. The sintering shrinkage of ceramic core is controlled by adding magnesium oxide power and developing a novel sintering process. After the resin mold is burnt out, the complex-shaped alumina-based ceramic core is obtained. 相似文献
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屠晓林 《特种铸造及有色合金》2009,29(12)
在精密铸造生产过程中,空腔结构铸件的内腔一般采用陶瓷型芯形成,但制造陶瓷型芯需专用工装,而专用工装制造成本高、周期长,而且陶瓷型芯制造工艺复杂、周期长.这种传统的空腔铸件成形工艺,往往不能满足新品研制周期的需要.通过对某燃机中介机匣的研制,提出了不用陶瓷型芯生产空心铸件的工艺方法,并在实际生产中得到了验证,取得了良好的效果. 相似文献
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Liu Yong Huang Baiyun Zhou Kechao He Yuehui Powder Metallurgy Research Institute Central South University of Technology Changsha 《中国有色金属学会会刊》1997,(1)
FABRICATIONOFAl2O3BASEDCERAMICMOLDFORCERAMICPROCESSING①LiuYong,HuangBaiyun,ZhouKechao,HeYuehuiPowderMetallurgyResearchInstitu... 相似文献
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In this work,aluminum oxide(Al_2O_3) ceramic samples were fabricated by 3D stereolithography printing.Printing process was followed by debinding and sintering.In addition,the effect of sintering temperature on micro structure and properties was investigated.Flexure strength was observed to increase with increasing sintering temperature due to fewer pores,fewer defects and stronger grain boundary bonding of samples at higher sintering temperatures.Maximum flexure strength of 138.5 MPa was obtained when sintering temperature was 150℃.Furthermore,the shrinkage along length direction decreased with the decreasing sintering temperature until reaching minimum value of 1.02% after sintering at 1200℃.After sintering at 1280℃,flexure strength was 24.0 MPa and the shrinkage along length direction was 2.1%,which meets demands of ceramic core. 相似文献
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基于选择性激光烧结技术的快速铸造 总被引:8,自引:0,他引:8
介绍了用选择性激光烧结(SLS)快速成型技术直接制造覆膜砂铸型(芯)的特点及工艺过程。结合铸件生产,分析研究了SLS铸型(芯)的工艺设计、三维实体造型及铸型后处理等过程中所遇到的问题。 相似文献
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复杂结构空心高压涡轮导向叶片精密铸造工艺 总被引:2,自引:0,他引:2
对双联复杂结构空心高压涡轮叶片的精密铸造工艺进行了研究。结果表明,采用硅基陶瓷型芯为主芯并组合石英管,使制备空心叶片铸造用陶瓷型芯工艺过程明显简单化,提高了陶瓷型芯的成品率。采用该型芯成功制备了合格的双联空心高压涡轮叶片。 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