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电磁铸造液柱高度数学模型的建立及应用 总被引:2,自引:1,他引:1
为了研究熔体金属电磁立柱成形能力并计算电磁作用下的液注高度,从电磁铸造立柱成形的基本原理出发,建立了电磁场作用下金属立柱成形时液柱高度数学模型,并试验验证了模型的准确性.利用液柱高度数学模型对铝、钢、锡铅合金等金属的电磁铸造可行性,以及电力参数对液柱高度的影响进行研究.结果表明:铝电磁无模成形能力最强,而钢及锡铅合金电磁无模成形能力则基本相同;钢及锡铅合金电磁立柱成形所需的磁感强度约为0.08~0.10 T,而铝则只需约0.04T. 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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In order to find the ways to improve the elimination efficiency with high frequency magnetic field, a mathematical model of electromagnetic elimination (EME) in the tubule with high frequency magnetic field was set up. The calculated results show that by ignoring the flow of molten metal, when the surface magnetic induction intensity of the metal (B0) is 0.03 T and the diameter of the tubule is 8 mm, the non-metallic inclusions with 30 μm diameter can be wiped offin 7 s from the center of the molten aluminum, whereas the elimination time of the 5 μm non-metallic inclusions is more than 240 s. When B0 is 0.03 T, the diameter of the tubule is 8 mm and elimination time is more than 30 s, the elimination efficiency of 5μm, 10μm and 30 μm non-metallic inclusions is about 60%, 90% and 100%, respectively, the elimination efficiency increases with the decreasing diameter of the tubule. It can be concluded that increasing the magnetic induction intensity or decreasing the diameter of the tubule can decrease the elimination time and improve the elimination efficiency in EME with high frequency magnetic field. 相似文献
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Hot top electromagnetic casting research of Al thin slab 总被引:3,自引:0,他引:3
Zhang Xingguo 《中国有色金属学会会刊》1999,9(3):4
1 INTRODUCTIONElectromagneticcasting(EMC)isamouldlesscontinuouscastingtechnologywithwhichliquidmetalisshapedbyelectromagneticforceandithasadvantagessuchas:smoothingotsurface,compact,homogeneoustissueandhighercastingvelocity.EMCtechnologyhasbeendev… 相似文献
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本文针对铝合金板料电磁翻边工艺过程,采用数值模拟方法,研究板料上的电磁力分布特性以及几何参数对电磁力分布的影响规律,并揭示电磁力分布对翻边件成形质量的影响。结果表明,铝合金板料电磁翻边中,预制孔的存在使板料上形成电磁力边缘积聚效应,板料预制孔径和成形线圈内径参数通过改变线圈投影面积比影响电磁力分布;随着线圈投影面积比的减小,电磁力边缘积聚效应更加显著,边缘电磁力密度增大;电磁力分布较均匀时,圆角区材料塑性流动更显著,成形件能获得更高的成形高度与更小的边缘减薄率,变形区厚度分布较均匀,成形质量更好。 相似文献
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1 INTRODUCTIONMacrosegregationisoneofthemostpronouncedde fectsduringcontinuouscastingofaluminumalloys ,whichleadstolarge scaleinhomogeneityofalloyingelements .AsatypicalAl Zn Mg Cualloy ,70 75alloy sas caststructurespresentsevereinversesegregation .Alloyingel e… 相似文献
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Continuous electromagnetic separation of inclusion from aluminum melt using alternating current 总被引:2,自引:0,他引:2
A novel scheme about the continuous electromagnetic purification of aluminum melt was put forward based on the utilization of a square separation pipe and a 50 Hz alternating current to produce electromagnetic force. It is experimentally found that with electrical current of 400 A/cm^2, it takes only 10 s to remove 95% inclusion from aluminum melt. Comprehensive numerical simulations were carried out to investigate the dynamics mechanisms behind the process. The results show that the removal of inclusion is attributed to the cooperative effects of electromagnetic buoyancy and the secondary flow induced by the rotational electromagnetic force, and the removal efficient increases with the size of inclusion and the electrical current imposed. Theoretical predictions on the distribution and removal efficiency of inclusion were supported by the experiments. 相似文献
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利用脉冲电磁场引起的力效应、热效应及磁势能可显著改善铝合金半连续铸造组织性能,同时,脉冲电磁铸造技术在绿色生产、智能控制等方面紧密契合“低碳冶金”的国家战略要求。综述了脉冲电磁场在铸造晶粒细化、微观结构演变及析出物细化3方面的研究成果,分析了脉冲电磁场特性与材料相变的耦合机制,提出了脉冲电磁场控制凝固、析出相变组织的初步构想,以满足高性能铝合金的质量要求。着重介绍了基于理论指导开发的熔体表面脉冲电磁场技术及其在7XXX(φ203)、6XXX(φ380)、Al-Si(φ120)等多规格半连续铸造的工业实践,脉冲电磁场有望在今后铸造、热处理等多个冶金环节发挥更大作用。 相似文献
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1 INTRODUCTIONElectromagneticcasting (EMC)isanadvancedmaterialprocessingtechniqueinventedbyGetselev[1]andhasbeenwidelyusedintheworldbecauseitsproductshavetheadvantagesofsmoothsurface ,ho mogeneousmicrostructureandgoodworkability[2 ,3] .ElectromagneticcontinuouscastingofsteelisanewtypemethodbroughtforwardbyVives[4 6 ] thatcom binedtheelectromagneticfieldwithcontinuouscast ingtechnique .Itisalsoanewideatoapplythismethodintotheshapingprocessofaluminumalloytoimprovethesurfaceandinnerquality… 相似文献
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回弹是弯曲成形的主要缺陷,传统的弯曲工艺消除回弹的效果并不理想.电磁成形是一种高速成形技术,能提高成形性能,改善应力分布,有效地控制回弹.以1060铝板为研究对象,提出一种用于V形件弯曲校正匀压力线圈,以利于提高成形效率,对不同厚度的铝板毛坯进行电磁弯曲校形实验.实验结果表明:随着放电能量的增加,V形件回弹逐渐减小直至消除;坯料越厚,消除回弹所需的能量越大;坯料宽度对工件回弹没有影响;在较低的能量下对工件进行多次放电,随着放电次数的增加,回弹逐渐减小,最终被消除;离折弯线区域越近,工件塑性变形功越大. 相似文献
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The effect of electromagnetic bulging on the fatigue behavior of the 5052 aluminum alloy was investigated through tensile–tensile fatigue testing. The intriguing finding is that the bulged specimens exhibited enhanced fatigue strength as depicted by maximum stress vs the number of cycles until failure (S–N) curves, by comparison with these original aluminum alloys. Although the fatigue process of the original and budged alloys follows the same mechanism with three distinct steps, namely, crack initiation at a corner of the tested samples, stable crack propagation with typical fatigue striations and finally catastrophic fracture with dimple fractographic features. The typical crack propagation rate vs stress intensity factor range (da/dN–ΔK) curves derived from the spacing of striations reveal a lower crack propagation rate in the bulged specimens. The enhancement of fatigue strength in electromagnetically bulged aluminum alloy is further rationalized in-depth on the basis of strain hardening and dislocation shielding effect. 相似文献
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对电磁铸造圆形感应器产生的磁场在金属熔体内的电磁作用力进行了理论分析和实验研究。指出导体中电磁作用力仅存在于径向及轴向方向上。电磁作用力的大小不仅与磁感应强度有关,还与磁感应强度的分布梯度有关;电磁有旋力是由于磁场分布不均匀造成的,其旋度方向在柱坐标系的周向方向上。试验研究分析了感应器结构、电流等工艺参数对电磁场分布的影响。 相似文献
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研究电磁场和钙微合金化对连铸造过程中变形镁合金微观组织和力学性能的影响。利用金相显微镜(MEF-4A)、X射线衍射仪(XRD-6000)、扫描电镜(JSM-5600LV)和电子探针(EPMA-1600)对制备的连铸造锭微观组织、相组成和元素分布进行分析,并利用MTS NFW-810型试验机对连铸造锭的力学性能进行考察。结果表明:电磁场和钙微合金化复合作用能连续铸造出表面光滑、无氧化夹杂和偏析瘤的高质量铸锭,合金的微观组织得到改善,施加电磁场和钙微合金化后变形镁合金AZ61连铸锭具有晶粒细小、析出相弥散分布的均匀组织;电磁场和钙微合金化均能提高变形镁合金AZ61的抗拉强度,合金的最大抗拉强度值达到259.4MPa,较直冷连铸AZ61镁合金的提高24.2%;但钙微合金化不利于提高AZ61镁合金的伸长率。 相似文献
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以某厂圆坯凝固末端电磁搅拌器为研究对象,建立了圆坯凝固末端电磁搅拌的三维数学模型。利用有限元软件ANSYS对电磁场的分布规律进行了数值模拟,研究了不同工艺参数对磁感应强度和电磁力分布规律的影响。研究结果表明:当电流频率为8 Hz,电流强度从100 A增加到400 A时,搅拌器中心处的磁感应强度从19.5 mT提高到77.9 mT,中心横截面上切向电磁力的最大值从115 N/m3提高到1 837 N/m3。当电流强度为300 A,电流频率从4 Hz增加到12 Hz时,搅拌器中心处的磁感应强度从60.3 mT下降到55.6 mT,中心横截面上切向电磁力的最大值从550.2 N/m3提高到1 501.8 N/m3。 相似文献
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Effect of turbulent flow on electromagnetic elimination with high frequency magnetic field 总被引:1,自引:0,他引:1
1 Introduction The application of the electromagnetic body force to separate non-metallic inclusions was proposed by ALEMANY et al[1,2]. And ASAI et al have measured the migration velocity of polystyrene particles in a sodium chloride aqueous solution, in which a DC electric field and DC magnetic field were simultaneously imposed. They found that the direction of migration is opposite to the electromagnetic force and the migration velocity agrees well with the values calculated from the … 相似文献