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1.
Electromagnetic separation of non-metallic inclusions from Al-Si melt is studied by theoretical analysis and experiments on self-designed electromagnetic separation apparatus. Metallographs and LECO Image Analysis System were used to analyze the content of alumina in aluminum alloy before and after electromagnetic separation. It is seen that removal effciency increases with the increase of electromagnetic force (EMF) and diameter of inclusion particles while decreases with the increase of melt velocity and height of separator. All alumina particles with diamete of 14μm have been removed successfully from the melt. 相似文献
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电磁过滤钢液中非金属夹杂物的运动速度和去除效率的理论分析 总被引:7,自引:0,他引:7
电磁过滤原理是根据非金属夹杂物与熔体导电性的差异,在电磁场作用下非金属夹杂物与熔体的运动规律不同,使非金属夹杂物与熔体分离,经流体力学分析、采用柱塞流及轨线模型研究电磁过滤水平流动钢液中非金属夹杂物的运动速度和去除效率,结果表明,非金属夹杂物的去除效率随着熔体流速(u)和过滤器的高度(2h)的降低而增加;随着电磁力(f)、电磁力作用区长度(x)和非金属夹杂物的粒径(dp)的增加而增加,经分析表明,采用电磁过滤法可有效去除粒径小于10um的非金属夹杂物,该模型可用来设计过滤器的结构和确定电磁过滤工艺参数,为电磁去除钢液中的非金属夹杂物技术的工业应用提供理论基础。 相似文献
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采用高频磁场去除太阳能级硅熔体中的SiC粒子(英文) 总被引:2,自引:0,他引:2
Mehdi KADKHODABEIGI Jafar SAFARIAN Halvard TVEIT Merete TANGSTAD Stein Tore JOHANSEN 《中国有色金属学会会刊》2012,22(11):2813-2821
高质量硅材料在光伏太阳能和电子设备中具有重要应用,然而原料中的非金属颗粒和金属杂质严重影响其电学性能和力学性能。由于SiC粒子会降低光伏电池的力学性能并导致分流问题,因此在制备太阳能电池之前必须将这些杂质从硅材料中去除。利用磁场去除液态金属中的非金属杂质是制备高纯金属的一项尖端技术。利用该方法去除冶金级硅材料中的SiC粒子,并结合杂质去除经典模型和计算流体力学对熔体中粒子浓度和分离效率进行计算。为检验该方法的有效性,采用感应炉进行多次实验。结果表明:该方法能有效去除非金属杂质,提纯硅熔体,且实验结果与模型的预测结果相符。 相似文献
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1 INTRODUCTIONIronisusuallyconsideredtobeharmfulimpurityinaluminum .Theneedle likeormassiveiron siliconinter metalliccompounds ,arenotonlycrackoriginsbutalsocrackgrowthpathswhichdramaticallyinfluencethestrengthandelongationofaluminumalloy .Thesehardandbri… 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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行波磁场连续净化铝合金液实验 总被引:9,自引:2,他引:7
采用行波磁场进行了电磁连续净化铝合金液实验,并采用电磁净化金属熔体的轨线模型,对实验中的夹杂物去除率进行了理论预测,结果表明,含夹杂的铝合金液连续液经电磁力作用段时,夹杂物被阻隔,形成电磁过滤效应,而夹杂物聚集区域夹杂物面积分数趋于某一常数,轨线模型预测与实验结果吻合良好。 相似文献
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X.Q. Bai J.C. He Key Laboratory of National Education Ministry for Electromagnetic Processing of Materials Northeastern University Shenyang China 《金属学报(英文版)》2001,14(5):375-379
1. IntroductionMicro-sized non-metallic inclusibns in metal are usually detrimental to the metal ma-trix from the points of precise machining, deformation and corrosion. Therefore, theseinclusions should be removed from molten metal by using an efficient separation method.The routine methods involve floatation-separation methodology based on natural densitydifferences, ceramic filters or fine~bubble-assisted floatation-separation, and new separa-tion methods using electric or magnetic flelds h… 相似文献
11.
Impurities such as Fe, Ni and Cu and non-metallic inclusions such as oxides, nitrides, carbides, sulfides and fluorides are
harmful to the quality and various properties of magnesium alloy sheets produced by twin-roll casting. In this study, the
changes of the content of Fe and non-metallic inclusions in AZ31B magnesium alloys with melt temperature and isothermal holding
time were quantitatively evaluated using EPMA and the metallographic method. The Fe content did not increase above the Fe
content in the raw material, which implies that the dissolution of Fe from a steel crucible was suppressed effectively. The
content of non-metallic inclusions, mainly consisting of oxide, fluoride and Fe-rich intermetallic compounds, did not change
remarkably with the melt temperature but it increased with the isothermal holding time due to the continuous oxidation of
the magnesium alloy melt on the melt surface. 相似文献
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A two-phase numerical model coupled with heat transfer was presented to describe the radial distribution of SiC particles on centrifugally-cast metal matrix composite,and a transverse static magnetic field was concurrently imposed to induce electromagnetic stirring of the melt as it revolved with the mold.Meanwhile,experimental observations were also carried out to examine the radial distribution of SiC particles in pure aluminum.The effects of the imposed magnetic field,particle size and the matrix metals were discussed.The computational results show that the particles tend to be congregated by the centrifugal force,and both increasing the imposed magnetic field and decreasing the particle size tend to result in even distribution of the particles.With the magnetic field varying from 0 to 1 T and the particle size from 550 to 180 μm,a uniform distribution of the particles in the aluminum matrix can be obtained among the computational results.The matrix metal can also influence the particle distributions due to the difference in physical properties of metals.Experimental observation shows similar tendency of particle distributions in aluminum matrix influenced by magnetic field and particle size.However,the chilling effect from the mold wall results in an outer particle-free zone,which is not involved in the numerical model. 相似文献
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用电解铝液生产铝合金扁铸锭的熔体净化工艺 总被引:3,自引:1,他引:2
针对电解铝液具有温度高、夹杂物多、空气含量高等特点,用电解铝液直接生产铝合金扁铸锭时,采取熔体预处理、两次炉内精炼和炉外在线除气、除渣,对熔体进行净化处理,可以获得纯洁度高的铝合金熔体. 相似文献
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Investigations were carried out into the relationship between the shape and composition of non-metallic inclusions, formed in the weld metal in welding E36 and AB steels with low-alloy wires under agglomerated fluxes of the MgO–CaF2–Al2O3–SiO2 system, and the composition of the flux. It is shown that the increase in the fraction of circular non-metallic inclusions and the reduction of the fraction of elongated inclusions in the weld metal, like the reduction of the mean size of the inclusions, increase the impact work of the weld metal at the test temperature of ? 40°C. 相似文献
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Varuzan Kevorkijan Sreco Davor Skapin Urban Dosler 《JOM Journal of the Minerals, Metals and Materials Society》2012,64(8):916-922
In recycling plants, especially those specializing in the recycling of low-grade aluminum scrap for wrought aluminum alloys, timely and accurate information about the amount of organics and other impurities in the incoming scrap is an important parameter in achieving both economic benefits and standard metallurgical quality of the recycled metal. To use aluminum scrap combined with organics as a source of aluminum for producing wrought aluminum alloys of standard quality, its metallurgical composition and the content of organic and other impurities should be quickly and cost-effectively analyzed on representative samples. In this work, an industrial thermogravimetric/differential thermal analysis of representative scrap samples was developed as an efficient analytical methodology for analyzing the humidity and organic impurities in incoming scrap. When performed in continuous mode, under a flowing atmosphere of argon with 1?wt.% of oxygen, this methodology enables a routine measurement of the humidity, the quantity of organics, and the carbon content in representative samples of incoming scrap in less than 15?min within an accuracy of ±0.5%. 相似文献
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Mohsen Ostad Shabani Fatemeh Heydari Ali Asghar Tofigh Mohammad Reza Rahimipour Mansour Razavi Ali Mazahery Parviz Davami 《Protection of Metals and Physical Chemistry of Surfaces》2016,52(3):486-491
There are many approaches to fabricate nanoparticles reinforced aluminum matrix composites. However, uniform distribution of nanoparticle within aluminum matrix remains a difficult challenge. In this study, a novel method is used by taking the advantages from squeeze casting of semi-solid aluminum slurry combined with electromagnetic field to refine the microstructure of the primary Al and eutectic Si phase, plus to obtain uniform distribution nano alumina particles in the aluminum matrix. It is noted that electromagnetic field plays an important role in the formation of non-dendritic primary α-Al particles and a great microstructure refinement occurs as a consequence of the pressure application. It can be seen that the increase in electromagnetic field causes smaller and rounder primary α-Al particles. A comparative study on abrasive wear behavior of nano Al2O3 reinforced aluminum metal matrix composite has been carried out in the present investigation. The mass loss of the pin was used to study the effect of Al2O3 addition on the wear resistance of the composite materials. 相似文献
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提出了电熔剂净化金属熔体技术,利用电流通过细束金属流时产生的电磁挤压力去除非金属夹杂物.采用活塞流模型,对夹杂物净化效率进行了理论计算.结果表明,增加电流强度、降低金属液流速、降低流束直径可以提高夹杂物去除效率,而降低流束直径还可以缩短夹杂物迁移距离,因此对提高夹杂物去除效果更为有利.采用含碳化硅铝熔体进行了验证实验,证明施加电流能使非金属夹杂物迁移至铝熔体表面.理论计算和实验证明夹杂物的电磁迁移是电熔剂净化技术中的主要机理. 相似文献
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The main impurities in aluminum melt are hydrogen and Al_2O_3,which can deteriorate melt quality and materials performance.However,the diffusion process of H atoms in aluminum melt and the interactions among Al atoms,Al_2O_3 and hydrogen have been studied rarely.Molecular mechanics and dynamics simulations are employed to study the diffusion behaviors of different types of hydrogen,such as free H atoms,H atoms in H_2 and H~+ions in H_2O using COMPASS force field.Correspondingly,force field types h,h1h and h1o are used to describe different types of hydrogen which are labeled as H_h,H_(h1h) and H_(h1o).The results show that the adsorption areas are maximum for H_(h1o),followed by H_(h1h) and H_h.The diffusion ability of H_(h1o) is the strongest whereas H_h is hard to diffuse in aluminum melt because of the differences in radius and potential well depth of various types of hydrogen.Al_2O_3 cluster makes the Al atoms array disordered,creating the energy conditions for hydrogen diffusion in aluminum melt.Al_2O_3 improves the diffusion of H_h and H_(h1o),and constrains H_(h1h) which accumulates around it and forms gas porosities in aluminum.H_(h1o) is the most dispersive in aluminum melt,moreover,the distance of Al-H_(h1o) is shorter than that of Al-H_(h1h),both of which are detrimental to the removal of H_(h1o).The simulation results indicate that the gas porosities can be eliminated by the removal of Al_2O_3 inclusions,and the dispersive hydrogen can be removed by adsorption function of gas bubbles or molten fluxes. 相似文献
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AN IN SITU SURFACE COMPOSITE AND GRADIENT MATERIALOF Al-Si ALLOY PRODUCED BY ELECTROMAGNETIC FORCE 总被引:1,自引:0,他引:1
Z.M. Xu T.X. Li Z.L. Zhu Y.H. Zhou School of Materials Science Engineering Shanghai Jiao Tong University Shanghai China 《金属学报(英文版)》2001,14(5):335-340
1. IntroductionAt present, the main processes fOr producing surface composite and gradient materialduring solidiflcation are casting infiltrationl1,2], electromagnetic stirring to separate eutec-tic process of the eutectic alloy[3l4], electromagnetic ..nt.iiug.l casting[5--7] and centrifugalcasting[s]. These processes, however, are complicated and require complex equipment;therefore, they are limited in application. The aim of this research is to develop a newmethod for production of in situ s… 相似文献
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WAMG Chunqi YANG Jiguang Tianjin University Tianjin China associate professor Faculty of Foundry Tianjin University.Tianjin China 《金属学报(英文版)》1993,6(12):411-415
Melted cast iron was inoculated by FeSi,then quenched to interrupt the dissolution,the non-metallic inclusions,in which the graphite phase was already occured,formed inthe dissolution region,They dissolved into the melt soon,but the inclusions coated bygraphite could exist for along time.The function of inoculant is to create an undercoolingsolution for carbon,thereby the non-metallic inclusions in the solution may be activatedas the nuclei for graphite. 相似文献