铝熔体中夹杂物形状与取向对其电磁分离的影响

采用有限元方法,对电磁场作用下铝熔体中任意形状与取向夹杂的受力进行数值计算。结果表明：不同形状与取向的夹杂均仅受到一个与熔体所受电磁力方向相反的斥力作用;电磁斥力的大小不仅与夹杂的形状有关,还受其取向的影响;当夹杂的形状奇异程度愈大时,取向对电磁斥力的影响也愈大;当夹杂在磁场方向的主轴长度较大,并且在电磁力方向的主轴长度较小时,夹杂所受电磁斥力不显著。     

利用高频磁场分离Al熔体中的非金属夹杂

对利用高频磁场分离静置Al熔体中非金属夹杂的工艺参数进行了研究,通过理论解析计算得出频率f,磁感应强度Be,颗粒直径dp,电磁力作用时间t,管径与集肤深度的比值r1/δ等参数与夹杂分离效率η的关系,并与实测分离效率进行了分析和比较,实验结果表明,较高的磁场频率和磁感应强度是高分离效率的保证,对于粒径为6um的非金属夹杂,磁场频率为高,则r1/δ的取值范围越宽;r1/δ=1.5-2时可使分离效率获得最大值。     

影响铝熔体电磁净化效果因素的分析

从液态金属电磁净化技术的原理出发,在理论上分析了当夹杂物与金属熔体密度接近的情况下,可以利用两者之间的电性能与磁性能的差异来实现夹杂物的分离,达到金属熔体净化的效果。综述了影响电磁分离效率和效果的因素。表明在电磁净化过程中,通电时间越长、磁感应强度越大、管半径与集肤程度比值在1.5~2.0之间、分离管为异型管、夹杂颗粒越大且近于球形,分离效果越理想,分离效率越高。     

铝熔体电磁连续净化工艺研究

通过一系列的试验,优化出了与电磁连续净化铝熔体有关的各工艺参数,如分离管径、长度和形状以及分离时间等,同时考察了电磁场等因素与净化效率的关系;提出了在线自动分割复杂熔体,并将分离出的夹杂部分或全部连续不断地移除的新方法;设计了一套自动化程度较高的连续电磁净化处理铝熔体系统,该系统既提高了净化效果,又提高了生产效率.     

铝熔体中夹杂物与气体相互作用的关系

分析了夹杂物（Ａｌ２Ｏ３等）的结构特性和气体（氢）在铝凝固过程中的行为,阐述了铝熔体中夹杂与氢的相互依存关系,提出了夹杂与氢相互作用的“寄生机制”观点。指出了夹杂的存在是气体难以除净的关键限制因素,排杂是除气的基础,并通过实验得到证实,对铝液净化实践具有实际指导作用,是提高铝材冶金质量的关键。     

铜合金中氧化物夹杂的电磁分离

通过向Cu-10Sn合金中加入1%的Cu2O颗粒制备了含有SnxOy合金的材料,随后利用高频磁场的电磁分离技术成功将铜合金中的氧化物夹杂分离到分离器边缘。研究了分离器直径、磁感应强度、分离时间对分离效果的影响。试验结果表明,当分离器直径为12mm,磁感应强度为60mT,分离时间为60s时,氧化物夹杂的分离效果最好。     

合金熔体在多通道分离器中高频电磁分离的试验研究

对Al-18%Si合金熔体存在垂直和水平多通道分离器中高频电磁分离进行了试验研究。试验结果表明,采用多通道分离器可以解决高频电磁净化中去除效率与熔体处理量之间的制约问题。电源功率与磁场作用时间的优化匹配是获得高分离效率的一个重要控制参数。     

铝合金熔体中夹杂物与含氢量的关系

采用英国ＨＹＳＣＡＮⅡ测氢仪研究铝合金熔体中夹杂物与含氢量的关系，结果表明：在夹杂沾污度超过２．５％时，熔体含氢量会增另３倍以上；同时也研究了夹杂物尺寸和熔炼温度对含氢量的影响。     

铝电磁铸轧中熔体的频率响应

介绍了在铝铸轧工艺中用频率交替变化的电磁场抑制晶粒长大的方法,阐述了粘性流体与电磁波频率响应的关系,分析了电磁场频率与熔体波动对晶粒细化效果产生的影响。结果表明在d650mm×1600mm铸轧机系统中,电磁场的最佳频域范围为11～15Hz。     

铝熔体过滤技术的应用与研究方向

阐述了过滤对于提升铝制品性能的重要意义,介绍了当前国内外铝熔体过滤采用的常规手段与先进技术,并从过滤机制、效用评价、活性过滤、提高过滤器寿命等四个方面提出了今后铝熔体过滤技术研究与应用的方向.     

Mechanism of removing inclusions from molten aluminum by stirring active molten flux

1　ＩＮＴＲＯＤＵＣＴＩＯＮＭｏｌｔｅｎａｌｕｍｉｎｕｍｉｓｓｏａｃｔｉｖｅｔｈａｔｉｔｅａｓｉｌｙｒｅａｃｔｓｃｈｅｍｉｃａｌｌｙｗｉｔｈＨ2 Ｏ(ｇａｓｅｏｕｓｓｔａｔｅ)ｉｎｍｅｌｔｉｎｇｏｐｅｒａｔｉｏｎ ,ａｎｄａｌｕｍｉｎａｉｎｃｌｕｓｉｏｎｓ(Ａｌ2 Ｏ3 )ａｎｄｈｙｄｒｏｇｅｎｇａｓ(Ｈ2 )ａｒｅｐｒｏｄｕｃｅｄ .Ｈｏｗｅｖｅｒ,ｓｏｍｅｎｏｎ ｏｘｉｄａｔｉｖｅｉｎｃｌｕｓｉｏｎｓ ,ｓｕｃｈａｓＴｉＢ2 ,Ａｌ4 Ｃ3 ,ＭｇＡｌ2 Ｏ4 ,ａｒｅａｌｓｏｐｒｏｄｕｃｅｄｄｕｒｉｎｇｔｈｅｅｌｅｃｔｒｏｌ…     

Removal of inclusions from molten aluminum with actively coated ceramic filters

1　INTRODUCTIONMoltenaluminumissoactivethatitreactseasilywithO2 andH2 OtoproduceAl2 O3inclusionsandH2duringmeltingpractice .However ,someinclusions ,suchasAl2 O3,Al4 C3,MgAl2 O4 etc ,areproducedduringelectrolyticprocess .Aluminum productscon tainingtheseinclusionswill probablyexhibit poortoughnesspropertiesinservice[1,2 ] .Theinclusionsof 30 μmindiametercannotre movedfrommoltenaluminumusing glassfibrouswebsorfoamceramicfilters .Fromkineticsofchemi calreaction ,itisshownthatliquidalu…     

交流电净化铝合金熔体

进行了工频交流电分离铝合金熔体中夹杂物的实验,探讨电流密度、通电时间、分离器管型等实验参数对夹杂颗粒迁移行为的影响.结果表明:电流密度越大、通电时间越长,分离效果越理想;施加4.7×106A/m2的交流电,并维持40 s通电时间,不同管型的分离器都获得了较明显的分离效果.实验证实单电流电磁净化金属液是可行的.     

交变磁场分离铝熔体中Fe、Si的金属间化合物

根据含Fe、Si杂质和铝熔体的导电性之间的差异．应用电磁场将其从铝熔体中分离出来。测量和分析了自制设备所产生的电磁场。将Mn加入到铝溶液中。把针状和树枝状的金属间化合物颗粒改变为块状和含角状的结晶体。并且在不同的试验条件下，利用电磁场净化预先配制好的合金。试验结果表明，变形后的杂质的分布会随着磁感应强度的改变而变化，加入Mn可以显著提高杂质颗粒的迁移效率。     

Dynamic electromagnetic separation of iron-rich phase inclusions from Al alloy

A lum inum alloy plays a very im portant role in m odern society [1]. As the advancem ent of m odern society, m aterial industry faces the challenge of sustainable developm entand society needs alum inum products ofbetter quality.H oweverthe finalalum inum products always contain certain am ountofinclusions [2] com ing from raw m aterialas wellasproduction process.These inclusionsare usually sm all in size and theirdensities are alm ostthe sam e as thatofthe m etalm elt.Asaresult,itisdifficult…     

Continuous electromagnetic separation of inclusion from aluminum melt using alternating current

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.     

Separation of inclusions from aluminum melt using alternating electromagnetic field

Effects of processing variables such as frequency of imposed magnetic field, imposed magnetic flux density, processing time, diameter of inclusions, and value of r1/δ on the electromagnetic separating(EMS) removal efficiency were analyzed theoretically. The higher the frequency, the wider the range of r1/δ will be. Removal efficiency reaches the maximum while r1/δ ranges from 1.5 to 2. And the experimental results on aluminum melt show that higher frequency and magnetic flux density make for higher removal efficiency, matching well with the theoretical results. When f is 15.6kHz, Be is 0.1T, and imposed time is 10s, more than 80% inclusion particles with 6μm diameter can be removed.     

利用最小二乘支持向量机预测铝熔体氢含量

提出了一种最小二乘支持向量机的铝熔体在不同温度和保温时间下的氩含量预测新模型.以2个主要影响因素加热温度、保温时间为输入,铝熔体中氢含量为输出,通过最小二乘支持向量机模型拟合输入与输出之间的复杂非线性映射关系.以铝熔炼实验数据为样本对模型进行学习训练,用训练好模型预测在一定影响因素下铝熔体中氢的含量.仿真实践表明该方法具有建模速度快、预测精度高、操作简便等优点,不仅克服了常规的BP预测模型的不足,而且性能优于标准支持向量机预测模型.     

Mechanism to remove oxide inclusions from molten aluminum by solid fluxes refining method

A novel flux charging method and a crucible quenching method were employed to study the mechanism of solid fluxes refining method regarding the removal of oxide inclusions (Al2O3) from molten aluminum.Electrochemical polishing method was adopted to prepare surfaces of the samples.Through experiments,the morphology of the residual solidified flux in the solidified samples as well as the wetting action of the molten flux during refining were observed for the first time.Three wetting regimes denoted by absorbing regime,engulfing regime and penetration regime correlating with the removal of oxide films (the most typical and common oxide inclusions in molten aluminum) were proposed in terms of different types and distributions of oxide films and different size ratios of the molten flux to oxide films.Particularly,from a thermodynamic point of view,for the first time,the penetration regime provided concrete evidence that the practical oxide inclusions can be wet by molten flux under ambient fluid of molten aluminum.A spreading model was proposed,according to which ingredients and size parameters of practical solid fluxes can be optimized.     

透气砖底吹净化铝熔体的除气效率分析

在线测量了透气砖底吹净化装置的除气效果,从除气动力学方程出发建立了除气效率的计算模型,计算了气泡尺寸,并考虑气体受热膨胀和合泡的影响对其进行了修正.试验结果表明,除气效率随N2流量的增加而增大,当采用N2作为净化气体时,除气效率在40%以内,而采用N2-Cl2混合气体时,除气效率提高约10%.修正后计算得出通过透气砖吹入铝液中的气泡尺寸约为4 mm,除气效率计算值与试验结果较吻合.除气过程中气泡利用效率为50%～70%.从动力学角度分析得出了提高除气效率的主要途径.