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介绍了正在发展中的几种高温用材料的强化相结构形式,着重分析了钽钨系合金材料中的连续硬质胞状强化结构的强化因素及其良好的强化效果.由此得出结论,金属材料尤其是高温应用的合金材料中的强化相正在向着连续结构的方向发展,利用连续强化相进行金属的强化,可在传统强化方式的基础之上进行协同强化和接力强化,连续结构强化无疑是金属强化机制中今后应该着力探讨和发展的一个重要方向. 相似文献
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为改善钽喷丝头的品质,提高其硬度和耐碱腐蚀能力,利用热丝CVD制备不同粒径的金刚石薄膜,并通过对钽衬底的碳化处理,成功使之沉积于纯钽喷丝头表面,对纯钽喷丝头进行表面强化。通过场发射扫描电镜观察,大粒径金刚石薄膜有少量孔隙,小粒径金刚石薄膜细腻致密。硬度测试结果表明,金刚石薄膜钽喷丝头表面硬度达HV1000以上,远高于纯钽及其它工艺处理后的钽喷丝头。可纺性试验结果表明,其性能都达到或超过传统喷丝头,完全可以取代成本高昂的铂金喷丝头。 相似文献
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钽金属是一种理想的医用金属材料,能够与人体软/硬组织发生整合。利用化学气相沉积方法,在可控多孔结构的Ti6Al4V合金支架表面沉积涂覆钽金属涂层,使其同时具备理想的三维孔隙结构和力学相容性,以及钽金属优异的生物学性能。研究结果显示,多孔钛合金支架表面涂层前后色泽发生明显变化,涂层后支架呈现钽金属色泽。扫描电镜和XRD分析进一步证明了多孔钛合金支架表面沉积物为钽金属。与美国Zimmer公司生产的多孔钽小梁金属相比,钽涂层多孔钛合金支架具备与人体皮质骨更相似的弹性模量和抗压强度,是一种理想的骨修复替代物。 相似文献
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《稀有金属材料与工程》1977,(2)
难熔金属的强化和应用,在文献[1]中已做了详细的评述。本文只简单地介绍一下,近两年来国外难熔金属(钨、钼、铌、钽)及其合金的研制概况。着重地介绍了在强化难熔金属合金方面所取得的进展;钼、铌的固溶软化;渗杂钨丝高抗蠕变性能的机理;铌——氢系和静液压挤压工艺在难熔金属加工方面的应用和难熔金属的防护。 相似文献
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由于钽的熔点高且有优良的延展性,钽被用作高温元件材料。钽的熔点为2996℃,仅次于铼(3180℃)和钨(3410℃)。钽具有优良的室温拉伸性(拉长21%以上),且容易用燃气-钨-电弧法(GTA)焊接。在焊接和未焊接的条件下,钽具有极低的韧性至脆性过渡温度(DBTT),并对其它难熔金属和活泼金属有较高的固体溶解度。全世界每年钽的消耗量约为900t。最大用途是电子工业,约占总消耗量的66%。其次是切削工具(22%)。约有6%用作超合金的高温强化添加剂。由于它的独特的腐蚀特性,钽和低钽合金也用于化学工业(3%),尤其是阀门、热交换器和卡口加热器。Ta… 相似文献
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采用高比容钽粉(<0.45μm)通过真空烧结的方法制备了多孔钽金属,研究了在1150℃条件下烧结保温的时间(10,20,30,40,50 min)对多孔钽金属的微观结构以及孔隙性质的影响。实验发现多孔钽金属的孔隙率在50%(体积分数)附近,其积累体积大小分布为0.08 cm3/g相似文献
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Tantalum—processing,properties and applications 总被引:1,自引:0,他引:1
W. Köck Dipl.-Ing P. Paschen Dr.-Ing 《JOM Journal of the Minerals, Metals and Materials Society》1989,41(10):33-39
Tantalum— the Earth’s 49th most abundant element— is frequently produced as a by-product of tin smelting. The metal is also extracted from concentrates by reduction with sodium or fused-salt electrolysis; tantalum carbide is produced by carburization of Ta2O5 or tantalum hydride. Sintering, electric-arc melting and electron-beam melting are used to refine and purify raw tantalum. Tantalum’s unique properties make it suitable for a number of diverse applications, including capacitors, chemical equipment, hard-metal tooling and alloys. Tantalum consumption is expected to increase in the capacitor market, because of the demand for electronics equipment. 相似文献
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A modified ECAP die by implementing the principles of indirect extrusion was fabricated to process refractory metals of Niobium and Tantalum. The main advantage of this modified technique over conventional method of ECAP is the reduction of frictional force during extrusion. Finite Element Method was utilized to demonstrate the difference between the extruding loads during the process. Several samples of Niobium and Tantalum were subjected to ECAP in different passes. Analysis of experimental results demonstrated a dramatic improvement in mechanical properties. Similarly, microstructure and XRD analyses of the samples showed noticeable enhancement in grain refinement of metals towards nanoscale. 相似文献
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The manufacture and fabrication of tantalum 总被引:2,自引:0,他引:2
Tantalum is a refractory and reactive metal that is ductile and easily worked, although it is somewhat challenging to weld
and machine. This article overviews tantalum’s properties and associated processing concerns.
Kurt D. Moser is currently a senior metallurgist with H.C. Starck. 相似文献
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本文探讨了钽粉镁处理降氧工艺:钽粉与还原剂镁粉充分混合,在真空或惰性气氛下800~950℃还原反应,出炉后酸洗除去残余还原剂等杂质。从加镁量、反应温度、反应时间、掺氮等参数分析影响降氧效果的各因素。通过对比试验得出:加镁量要稍过量,为钽粉含氧重量的300%为宜;反应温度在900℃以下降氧效果不明显,反应温度越高,降氧效果越好,但温度过高会减少钽粉比表面积,导致比容降低;反应时间需≥3h,时间过短反应不充分,达不到降氧效果;反应完后掺入杂质氮可以降低钽粉中氧含量,出炉前用一定比例的氧气钝化钽粉,可以增强降氧效果。并通过工艺实践,确定了镁处理降氧的最佳工艺参数。 相似文献
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利用磁控溅射法在GCr15轴承钢表面沉积厚约100nm的钽膜,然后对其进行氮等离子体基离子注入,注入能量为50keV,利用GXRD分析改性层的组成相结构,用Φ6mm的氮化硅球作为对磨件测试处理后试样的磨损性能,并利用SEM结合EDX观测磨痕的形貌及成分,探讨其磨损机制。结果表明,改性层含有钽的氮化物,注入剂量较低时,化合物是TaN0.1,随着注入剂量增加,形成TaN;GCr15钢经过处理后能够提高磨损性能,摩擦系数有所降低:表面经过处理后,摩擦系数由未处理前的0.8~1下降至0.2~0.3,同时磨损量大幅度降低,降低幅度达到88%。注入层的磨损机制主要以磨粒磨损为主,兼有粘着磨损。 相似文献
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Tantalum and oxidized tantalum exhibit distinct differences when treated with plasma-based ion implantation of methane with − 20 kV. The implantation profiles of carbon are similar, but carbides are formed in the case of tantalum, as verified with X-ray diffraction and X-ray photoelectron spectrometry in combination with depth profiling, whereas there is no detectable carbide in the tantalum oxide film. The distributions of the co-implanted hydrogen also vary in that the intensity in depth profiling with secondary ion mass spectrometry does steadily decrease in the oxidized Ta, while in the metallic Ta it shows a short indentation below the surface and then decreases only very slowly. 相似文献