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双语推荐：等离子弧熔炼

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TiAl合金密度小、高温性能优异,自20世纪50年代以来已发展到第三代。介绍了TiAl合金的性能特点、发展历程,真空感应熔炼、真空自耗电弧熔炼、等离子冷床炉熔炼等熔炼TiAl合金方法的优缺点,以及国内外TiAl合金的制备情况;提出TiAl合金熔炼过程中存在的问题主要是宏观与微观偏析,应从原料加入方式、原料纯度及熔炼工艺等方面进行改进;此外,对TiAl合金在航空航天、汽车工业等领域的应用现状进行了概括,指出TiAl合金近期的研究重点是大尺寸铸锭的均匀化控制。
TiAl alloy has low density and good performance at high temperature , and has developed to the third gener-ation since the 1950 s.The performance feature , development process , preparation conditions at home and abroad , and the traditional melting methods ( vacuum induction melting , vacuum arc melting and plasma melting ) of TiAl alloy were also introduced .Then the main problems in the smelting process of TiAl alloy were indicated to be macro segrega -tion and micro segregation , and should be improve through adding method and purity of raw material and melting process control .The application status of TiAl alloy in the fields of aviation , aerospace and automobile industry were summarized, and the development trend of TiAl alloy in the near future was homogenizing control of large size TiAl alloy ingots .

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介绍了难熔金属及其合金单晶的制备技术，对电子束悬浮区域熔炼技术和等离子弧熔炼技术进行了比较。电子束悬浮区域熔炼法温度梯度易于控制、材料不受坩埚材料污染，但熔体表面张力对活性杂质和温度梯度敏感性高，所能制备的高纯难熔金属及其单晶材料尺寸规格受到很大限制，且材料内部位错密度较高。等离子弧熔炼法加热源能量密度高，原料规格形式多样，可制备单晶棒材、板材、管材及其他特定形状的单晶铸件，可最大程度地去除杂质元素（尤其是C元素），但设备系统复杂，单晶材料位错密度大。讨论了单晶材料发展现状，通过固溶强化可进一步提高材料的高温性能及其稳定性。单晶管材的制备也是一个发展方向。此外还对单晶材料制备技术和发展前景提出了一些建议。
In this paper,we report the processing technology of single crystals of high-purity refractory metals and alloys, and compare the electron-beam floating zone melting(EBFZM)with the plasma arc melting(PAM).By EBFZM,the tem-perature gradient could be controlled easily and the contamination by crucible materials is avoided,whereas the surface tension of melt is sensitive to the active impurity content and the temperature gradient.Furthermore,the dimensions of high-purity refractory metals and the monocrystalline materials are severely limited and the dislocation density in the mate-rials is relatively high.PAM has the advantages such as high energy density of heating and various specifications of raw materials,by which the single crystal castings could be processed in the shape of rod,plate,tube and other specific shapes.Meanwhile,the impurity elements (especially carbon)are maximally removed.However,the equipment is com-plex and the dislocation density is high.We also discuss t

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为获得高纯金属铟,对区域熔炼装置和工艺条件进行了优化。在熔区移动速度为3 cm/h时,根据熔炼次数(n)改变熔区宽度与料锭长度比(l/L),即n=1~4时l/L=0.2,n=5~9时l/L=0.1,n=10~16时l/L=0.05,在高纯氩气保护下将含量约为99.98%的原料铟提纯至99.999%,其杂质总量从211.003μg/g降低至9.864μg/g。此外,还利用电感耦合等离子质谱(ICP-MS)、扫描电镜(SEM)、X射线衍射(XRD)和差热分析(DSC)等方法讨论了区熔过程中金属铟杂质分布与金属微观结构演变之间的关系。
In order to prepare high-purity indium, the zone-refining device and conditions were optimized. The purity of indium was increased from 99.98% to 99.999% with the decrease of total impurity content from 211.003 μg/g to 9.864μg/g under the protection of high-purity argon at a treating rate of 3 cm/h by changing the ratio of melting zone width to ingot length( l/L) according to the melting frequency( n) , that is, l/L=0.2, 0.1 and 0.05 at n=1~4, 5~9 and 10~16, respectively. The relationship between impurity distribution and metal microstructure variation in the process of zone-refining of the indium ingot was also discussed based on the results of ICP-MS, SEM, XRD and DSC analyses.

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以锡作捕集剂，通过调整试金配料，将熔矿温度提高到1100℃，解决了锡试金熔炼困难、不易成扣和扣回收不稳定现象。通过增加助熔剂和覆盖剂，改进了熔渣流动性及样品溢出的问题。对捕集了贵金属的锡扣用盐酸溶解锡、镍等，过滤后王水溶解金、铂、钯沉淀物，并用电感耦合等离子体质谱法测定。对国家标准物质的分析结果与标准值相一致，各元素的RSD在5％～14％之间。对5个地质样品进行结果比对，采用锡试金法与铅试金法前处理测得的金、铂、钯结果相符。该方法在生产实践中已得到了应用，适用于地质样品中金、铂、钯的分析。
The difficulties of tin melting and the button recovery instability were solved by using the trapping agent of tin, adjusting the assay ingredient and increasing the molten ore temperature to 1100℃. Meanwhile, the slag fluidity and the overflow of the sample were improved by adding the flux and covering agent. Tin button with precious metal was dissolved and filtered, then the residue was dissolved with aqua regia and diluted with water. Au, Pt and Pd were determined by ICP-MS. The analysis results were consisted with standard values of the national standard reference materials, and the RSD value was 5%~14%. Au, Pt and Pd in geological samples were determined with tin fire assay method and lead fire assay method respectively, and their results are consistent. This method is suitable for the determination of Au, Pt and Pd in geological samples.

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本文针对Sm3Co粗晶和纳米晶合金材料的制备和基础性能进行了研究.采用磁悬浮熔炼技术多次精炼制备出Sm3Co粗晶合金.以此为母材,利用高能球磨非晶化和放电等离子烧结致密化并同步晶化的技术路线,制备出平均晶粒尺寸为8 nm的超细纳米晶Sm3Co合金块体材料.构建了Sm3Co纳米晶合金的晶体结构模型,并结合其显微组织的表征,分析了Sm3Co纳米晶合金的磁性能和力学性能,并与粗晶合金进行了比较粗晶Sm3Co合金不具有硬磁特性,而同种成分的纳米晶合金则表现出一定的硬磁特性.纳米晶Sm3Co合金的显微硬度和弹性模量分别达到4.87 GPa和63.7 GPa,比粗晶合金增大约8.7%和13.3%.本文研究结果为Sm-Co体系合金的基础性能及其纳米尺度效应提供了系统的参考依据.
In this paper, a novel fabrication process of the nanocrystalline Sm3Co alloys and their fundamental properties were studied. The polycrystalline Sm3Co bulk material was prepared by the vacuum melting method. By using the polycrystalline Sm3Co bulk metal, the nanocrystalline Sm3Co alloys with an average grain size of about 8 nm was prepared by combined ball milling and spark plasma sintering. The crystal structure model was constructed and the magnetic and mechanical properties of the polycrystalline and nanocrystalline Sm3Co alloys were characterized and compared with each other in detail. Results show that the nanocrystalline alloys exhibit magnetic properties and high mechanical properties. Microhardness and elastic modulus of the nanocrystalline Sm3Co alloys are 4.87 GPa and 63.7 GPa, respectively, which are increased by 8.7%and 13.3%as compared with the polycrystalline alloys.

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