共查询到19条相似文献,搜索用时 125 毫秒
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提出一种真空区域熔炼法制备高纯铝的新工艺。通过确定平衡分配系数,研究杂质的轴向偏析。理论分析和实验结果表明,平衡分配系数k0<1的杂质(Cu、Si和Fe)在铝锭尾部累积,而Ti (k0>1)在铝锭首端累积。当熔区以1.5 mm/min的速度移动并进行15次区域熔炼后,杂质的去除率和铝的纯度最高。在铝锭中部,即距铝样首端140 mm处,铜、铁和硅的去除率均高于90%,钛的去除率高于75%,铝纯度高于99.999%。铝样品的纯度符合99.999%(5N)工业用高纯铝标准的要求。 相似文献
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《特种铸造及有色合金》2016,(10)
从原料的角度分析了电解铝所用的氧化铝、氟化铝、阳极覆盖料、炭阳极中杂质含量对铝液质量的影响。通过跟踪这4种原料中Si、Fe杂质元素的迁移、转化和富集,研究了其对铝液中Si、Fe含量的影响大小。结果表明,这4种原料所造成铝液中Si、Fe的增加值最大分别为55.67%和62.15%。可以通过控制原材料质量、净化阳极覆盖料、提高炭阳极质量及优化电解生产工艺技术参数等来提升铝液质量。 相似文献
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《组合机床与自动化加工技术》2021,(6)
铝电解工业中,铝液中杂质元素含量过高会严重影响铝液质量,Fe和Si含量的预警和控制对保证铝液质量有着重大意义。针对铝液中的杂质含量过高,缺乏用于实时监督的准确预警模型的问题,提出了一种基于加权欧式距离的GNG增量学习模型,构建了阈值机制实现对工业数据流实时监督和预警。通过K-means算法、经典GNG算法与改进GNG算法进行网络拓扑图比较分析。最后,结合铝液中Fe和Si含量的时间序列数据进行动态特征分析,实验结果表明,改进GNG算法对Fe和Si含量数据的实时监督和预警具有可靠性与准确性。 相似文献
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在本研究中,通过冷坩埚感应区熔提纯铈以避免坩埚材料的污染。溶质再分配数值模型结合遗传算法搜寻优化区熔参数以提高溶质的再分配效率,并考虑变溶质分配系数对计算结果的影响。15次区熔后的化学结果分析显示,具有相近分配系数的Fe和Ni在试棒中部分别降低50%和90%,主要差别为初始含量不同。实验结果和计算结果的主要差别源于后续区熔实验过程中较窄熔区的不稳定。研究结果表明,GA是一种获得最优熔区长度的有力工具,但是需要采取有效办法获得稳定的熔区以促使杂质顺利迁移,另外杂质的初始含量应尽可能降低以获得好的提纯效果。 相似文献
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感应区域熔炼法制备高纯铜 总被引:1,自引:0,他引:1
在真空条件下用感应区域熔炼法对工业纯铜(99.99%)进行提纯。采用旋转样品的方式有效减小熔区宽度并加大了熔区的搅拌。ICP-AES结果表明区熔对Mo、Fe、W、Cr去除效果明显,纯度最终达到99.997%。结合溶质分配系数k计算了区熔后铜中杂质的分布情况,计算结果与实验数据吻合较好。 相似文献
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研究了电子束熔炼提纯钨过程中典型杂质的脱除,考察了电子束熔炼提纯钨的可行性,对电子束熔炼过程中的除杂动力学进行了分析,并确定了110、130、250 kW功率条件下杂质Fe、Si、Ti的脱除速率控制机制。结果表明:除Mo外,电子束熔炼对基体钨中各种杂质均有不同程度的脱除,其脱除率与饱和蒸气压差存在对应关系;通过分析并结合电子束熔炼实验,确定了Si、Fe、Ti在110 kW时的传质系数分别为0.21、0.56、0.11×10-4 m/s,在130 kW时的传质系数分别为0.83、3.04、1.78×10-4 m/s,在250 kW时的传质系数分别为0.36、2.37、1.48×10-4 m/s,表明其脱除速率控制机制均为液/气界面中的扩散。 相似文献
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Xiao-wei ZHANG Rui-ying MIAO Dao-gao WU Qiong ZHU Zhi-qiang WANG De-hong CHEN Shi-hong YAN 《中国有色金属学会会刊》2017,27(6):1411-1416
The distribution rules of impurities in distilled terbium metal were investigated by vacuum distillation purification experiment and theoretical analysis. It is found that Ti impurity in distilled terbium is 220 mg/kg in the initial stage of the distillation purification, increases slowly in the middle stage, and increases rapidly in the last stage, reaching 2260 mg/kg, and the modified separation coefficient of Ti is 1/19.02. The diffusion of the impurity Ti in liquid metal can reach a quasi-equilibrium state in the initial stage of distillation purification and the calculated results agree well with experimental results; the distribution profile of impurity Cu is opposite to Ti, being 380 mg/kg in the initial stage, decreasing linearly to 290 mg/kg in the last stage, and the modified separation coefficient is 17.99, and the theoretical calculated results are inconsistent with the experimental result. 相似文献
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Study of ultrahigh-purity copper billets refined by vacuum melting and directional solidification 总被引:1,自引:0,他引:1
The purpose of this paper is to study large-sized copper billets refined with 5N ultrahigh purity after vacuum melting and directional solidifi-cation (VMDS). The precise impurity analysis of copper billets was carried out with a glow discharge mass spectrometer (GDMS). The re-sults demonstrate that the total concentration of twenty-two impurities is decreased by 63.1wt.%-66.5 wt.%. Ag, P, S, Na, Mg, Se, Zn, In and Bi are easy to be removed due to lgPimp - lgPCu > 1.5, and they can be removed effectively under the vacuum condition of 1650-1700 K for 30 min. The electrical conductivity of 5N copper is higher than that of the raw material as the impurity concentrations decrease. The segrega-tion effect in directional solidification can be remarkable when the equilibrium distribution coefficient (k0) value is less than 0.65 due to the strong affinity of Cu for some metallic and non-metallic impurities. 相似文献
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1.IntroductionItispossiblethatbifurcatinganddeflectingduringthecrackpropagationanddelaminatingonthefracturesurfacecancauseanadditionaltougheningbehaviourfortheengineeringmaterials.Theadditionaltougheningbehaviourfromthesefracturepatternsbelongstotheextrinsictougheningscope.Theextrinsictougheningandthenaturaltoughening,ortheintrinsictoughening,arethedecisivefactorsforthetotaltoughenillglevelofthematerials.Ingeneral,thetotaltougheninglevelcanbeobjectivelyreflectedbythematerialfracturetoughness.… 相似文献
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预变形及退火对高纯铝箔立方织构的影响 总被引:2,自引:0,他引:2
应用TEM和晶体取向分布函数方法研究和分析了预变形和退火工艺对高纯铝箔立方织构的影响。研究结果表明 ,预变形及退火主要通过影响晶体内的储存能大小 ,来影响Fe、Si的析出过程 ,影响成品箔材中立方织构 { 10 0 }〈0 0 1〉取向密度的大小。由于成品退火前Fe、Si能充分固溶在铝基体中 ,成品低温退火阶段可促使Fe、Si析出 ,增加立方取向晶粒的形核率 ,使成品在高温退火阶段晶粒沿立方取向择优长大 ,大大增加了高纯铝箔中立方织构的比例 相似文献
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PreparationofHigh-puritySodiumTungstatefromLow-gradeTung-sten-concentratewithaHighContentofCalciumandOtherImpuritiesSunPeimei... 相似文献
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A. V. Pozdniakov A. R. Aitmagambetov S. V. Makhov V. I. Napalkov 《The Physics of Metals and Metallography》2017,118(5):479-484
The effect of impurities of Fe and Si on the microstructure and kinetics of the change in the hardness during annealing of the cast Al–0.2% Zr–0.1% Sc and Al–0.2% Zr–0.1% Sc–0.2% Y alloys has been studied. It has been found that the presence of the impurities of Fe and Si in the Al–0.2% Zr–0.1% Sc alloy leads to a partial binding of scandium into the (Al, Fe, Si, Sc) and (Al, Fe, Sc) phases of crystallization origin and to the corresponding depletion of the aluminum solid solution of Sc. It has been shown that as a result, the strengthening is significantly decreases upon annealing. The addition of 0.2% Y into the Al–0.2% Zr–0.1% Sc alloy with impurities of Fe and Si leads to the formation of the Al3Y and (Al, Y, Fe, Si) phases, whereas Sc is completely dissolved in the aluminum solid solution. It has been shown that the addition of Y leads to an increase in the thermal stability of the alloys during annealing at temperatures of 250, 300, and 370°C and eliminates the negative effect of impurities of Fe and Si. 相似文献
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贝氏体/马氏体复相高强钢中的氢陷阱 总被引:4,自引:0,他引:4
运用电化学渗透技术研究了传统高强钢(42CrMo)和贝氏体/马氏体复相高强钢(U20Si)中氢的扩散和氢陷阱。结果表明,氢在U20Si钢中的扩散系数远小于在淬火回火的42CrMo高强钢中的。另外,两种材料中氢陷阱的情况不同,U20Si钢中的氢陷阱主要为高度均匀弥散分布的贝氏体/马氏体板条界和薄膜状残留奥氏体,而42CrMo钢中的氢陷阱主要为铁素体/渗碳体界面。U20Si钢中的氢陷阱数量超过42CrMo钢的。力学性能测试表明,U20Si钢的氢脆敏感性低于传统的42CrMo钢的。断口分析显示前者的断口为准解理,后者的断口为沿晶断裂。U20Si钢氢脆敏感性低与其氢陷阱数量多且分布均匀密切相关。 相似文献