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电磁铸造法的现状和未来 总被引:2,自引:0,他引:2
一、序言1953年Alcoa公司及VLW公司(Vereingte Leicht metallwerke GmbH)的直接水冷铸造可以看作为铝连续铸造法的开端.以后的五十年,铝连续铸造技术得到显著的发展,开发了各种铸造法:热顶铸造法,水平铸造法,熔体轧制法(铸轧法一译者),还有电磁铸造法(Electro magnetic casting,以下简称为EMC)等.在铝的范围内,由此而开发和研究了许多铸造工艺,它们实现工业化之所以快,是因为熔体金属容易处理,其导热性良好,用结构简 相似文献
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电磁泵系统在铸造中的应用 总被引:2,自引:0,他引:2
电磁泵技术适用于液态金属的输送,在铸造行业特别是有色金属特种铸造行业具有很大的优势.介绍了电磁泵系统的国内外发展概况;电磁泵的分类、工作原理及相关工作参数;电磁泵系统在压铸、低压铸造及连续铸造中的应用及优点. 相似文献
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低频电磁场参数对Al-10Zn-2.5Mg-2.5Cu-0.15Zr合金铸态组织和性能的影响 总被引:8,自引:0,他引:8
采用低频电磁半连续铸造技术,制备了一种新的超高强高韧10Zn-2.5Mg-2.5Cu-0.15Zr铝合金锭坯,考察了电磁场参数频率和强度对铸态组织的影响.结果表明,低频电磁铸造组织均匀、细小、等轴,呈蔷薇形和球形,平均晶粒尺寸为20—40μm;适当增加电磁场频率和安匝数有利于细小均匀的等轴晶组织的获得;最佳的电磁场参数为:电磁场频率为25—35Hz,安匝数为12800—16000AT.相对于常规直接水冷铸造,低频电磁铸造提高铸态拉伸强度极限和延伸率. 相似文献
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铝合金扁锭热顶电磁铸造技术 总被引:2,自引:0,他引:2
根据热顶-电磁铸造的基本思想,设计了一套适合于制取铝合金扁锭的热顶-电磁成型系统,用小线圈法测量了系统内的磁场强度,计算了电磁压力分布,并与普通电磁铸造成型系统的结果进行对比分析;依据热顶电磁铸造的成型条件,确定了相关的控制参数;通过大量的拉坯实验,探讨了热顶对防止电磁铸造坯易产生表面夹杂缺陷的作用.结果表明:采用热顶-电磁铸造法不仅可有效去除电磁铸造中因电磁搅拌产生的氧化夹杂,而且使得电磁铸造过程简便而易于控制. 相似文献
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Microstructures of electromagnetic casting and direct chill casting LY12 aluminum alloys 总被引:1,自引:0,他引:1
1 INTRODUCTIONElectromagneticcasting (EMC)isatechnologydevelopedbythecombinationofmagnetohy drodynamics (MHD )andcastingengineering[13] .TheEMCtechnologydependsontheelectromagneticforcetopreventthemetalfromtouchingthemold .Dependingontheinteractionofeddycurrentsinducedinthemetalandthemagneticfieldoftheinductor ,theliquidmetalcolumniskeptstable[4 6 ] .Thecon tactlesscastingofEMCmayeliminatetheliquidationbuild upsandfeathercrystals ,relievethescalpingop erationbeforethehotrollprocess … 相似文献
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P. Wang L.F. Shi G.M. Lu J.Z. Cui 《金属学报(英文版)》2005,18(5):653-658
The microstructures of ZL201 alloy slurry prepared by near-liquidus electromagnetic casting (NLEMC), electromagnetic casting(EMC), and near-liquidus casting(NLC) were investigated by means of electron microscopy and image analysis. Mechanical properties of as-cast alloys were determined. The results show that the NLEMC induces a fine, uniform, and equiaxed grain structure with a mean equal-area-circle grain diameter of 32.8μm. The as-cast aUoy has a hardness of HV122.8 and a tensite strength of 368MPa. Both of them are betterthan those of the alloys prepared by EMC and by NLC. The mechanism of grain refinement in the NLEMC alloy slurry was discussed. 相似文献
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AZ61镁合金软接触电磁连铸的研究 总被引:5,自引:0,他引:5
采用软接触电磁连铸法制备了AZ61镁合金铸锭,对其晶体结构、金相组织、力学性能及抗腐蚀性能进行了研究,并与金属模铸法制备的铸锭作了比较。实验发现:两种方法制备的铸锭相结构相同;软接触电磁连铸铸锭晶粒细小,第二相弥散分布,促使其力学性能有很大提高,常温抗拉强度和延伸率分别提高了约30%和27%,其断口形貌具有更多韧性断裂的特征;在3.5%NaCl溶液中的动电位极化测试表明,软接触电磁连铸可以使镁合金的自腐蚀电压升高,腐蚀电流密度降低,从而提高镁合金的耐腐蚀性能。 相似文献
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Q.A. Li H.Q. Mo Y.Z. Huo G. Sang Y.F. Chen M.G. Han Y.G. Chen M.J. Tu Department of Metal Materials Sichuan University Chengdu China 《金属学报(英文版)》2000,13(2):770-775
1.IntroductionHydrogenstoragealloyismainlyusedasnegativeelectrodematerialintheNickel--metalhydride(Ni--MH)rechargeablebattery.Becauseofitshighcapacityandlongcycle--life,Ni--MHbatteryhasmadeupmorethan40thepropertyidentityofthebatteryisnotverygood.Oneofthecausesisthatthemicrostructurehomogeneityofhydrogenstoragealloyisnotcontrolledwell.Althoughgasatomizationandrapidquenchingmethodscanproduceafineandhomogeneousmicrostructure,theyarenotsuitableforlarge-scaleproductionbecauseoftheirverylowproduc… 相似文献
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The influences of out-phase electromagnetic field on the as-cast structure of horizontal direct chill casting aluminum alloy ingot were experimental by and numerical by studied. The results of numerical analysis show that the interaction of the out-phase electromagnetic field and the melt can generate an electromagnetically induced forced flow in the melt, which, in turn, changes flow pattern and temperature field in the mold. The as-cast structure of the ingot can be greatly improved by the changes of flow... 相似文献
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电磁振荡对铝合金连铸过程中热裂纹生成的影响 总被引:2,自引:0,他引:2
半连续铸造铝合金过程中,采用同时施加与铸锭对称轴方向平行的稳恒磁场和交变磁场,促使熔体产生受迫热振荡的方法,一方面通过减小不可补缩区间,降低内应力或应变,使金属高温脆性区主要处于受压状态等方式,减少了热裂纹形成的外部诱因;另一方面,通过缩小合金材料高温脆性区,提高固液状态伸长率,减少晶界低熔点化合物数量和有效结晶区间线收缩大小等途径,降低了合金铸锭的热裂倾向性,从而达到了消除铸造裂纹的目的. 相似文献
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The influences of the low frequency electromagnetic field on the horizontal direct chill casting process were investigated experimentally. Ingots of 2024 aluminum alloy with a cross size of 40 mm× 200 mm were produced by the conventional horizontal chill casting process and low frequency electromagnetic horizontal chill casting processre- spectively. The as-cast structures and the mechanical property of the ingots were examined. The results showed that the low frequency electromagnetic field could sub- stantially refine the microstructures and pronouncedly reduce the macrosegregation in the horizontal direct chill casting process. Moreover, the surface quality of the ingot was prominently improved by the low frequency electromagnetic field. The fracture strength and elongation percentage of the ingot was increased with the low frequency electromagnetic field. 相似文献
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基于等径角挤压(ECAP)的超细晶铸造镁合金制备研究 总被引:2,自引:0,他引:2
研究了铸造镁合金等径角挤压(ECAP)的原理与技术实施手段.通过设计ECAP模具的几何结构,研究了剪切应变累积效应的度量方法.通过对AM60镁合金铸锭单道次ECAP加工后光学显微组织的观察,讨论了模具几何结构条件(转角与背转角大小)对变形组织演化形态的影响.根据多道次ECAP试验的位移-挤压力关系曲线,考察了加工工艺条件(加工道次数、背压与加工速率)对变形组织形态的影响规律.分析了镁合金ECAP加工技术的试验和模拟方案.研究表明:AM60镁合金铸锭的ECAP变形组织形态较好地符合理论预测结果;多道次ECAP加工显著改善了AM60镁铸锭的微观组织;对于具有粗大晶粒的铸造镁合金而言,ECAP工艺能以机械化冶金方式制备其超细晶结构. 相似文献
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The present work investigated the solidification microstructure of AISI M2 high speed steel manufactured by different casting technologies,namely iron mould casting and continuous casting.The results revealed that the as-cast structure of the steel was composed of the iron matrix and the M2C eutectic carbide networks,which were greatly refined in the ingot made by continuous casting process,compared with that by the iron mould casting process.M2C eutectic carbides presented variation in their morphologies and growth characteristics in the ingots by both casting methods.In the ingot by iron mould casting,they have a plate-like morphology and grow anisotropically.However,in the ingot made by continuous casting,the carbides evolved into the fiber-like shape that exhibited little characteristics of anisotropic growth.It was noticed that the fiber-like M2C was much easier to decompose and spheroidize after heated,as a result,the carbides refined remarkably,compared with the case of plate-like carbides in the iron mould casting ingot. 相似文献