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通过比较指示电极对的测定精度,拟定一个用银指示电极,Ag-Agl参比电极,氯化钠电位滴定测定纯银及银基合金中银的方法.大量Cu(Ⅱ)、V(Ⅴ)、Ni(Ⅱ)、Al(Ⅲ)、Zn(Ⅱ)、Ce(Ⅲ)、Pb(Ⅱ)的存在不影响银的测定,Pd(Ⅱ)的干扰可在一定酸度下用EDTA配合消除.方法用于银基合金中银的分析,简便,准确. 相似文献
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采用自主设计的带有气氛保护、冒口保温、磁力搅拌和强制冷却功能高频熔炼-铸造-搅拌一体化设备制备银基合金靶材坯料。研究了Au、Ge协同作用对银基合金靶材坯料的组织和性能的影响。结果表明,随着Au、Ge添加量的增加,银基合金靶材微观组织细化,二次枝晶变短,抗硫化性提高,且在Au、Ge添加量均为1.0%(质量分数)时,银基合金靶材坯料的耐硫化性能最佳。随着Au Ge添加量增加,元素偏析现象加剧,在Agl.5Cu0.1Y1.5Au靶材的晶界处出现少量的富集区,使靶材的抗硫化和耐蚀性有所下降。 相似文献
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目前工业上分离高纯氢气应用最多的是致密金属膜,尤其是钯银合金膜。钯、银属于贵金属,大规模应用成本高。钒基合金膜拥有比钯银合金膜更高的透氢率、机械强度和较低的成本,且氢脆抗力较纯钒得到很大提高,成为潜在的替代钯银合金膜的材料之一。本文综述了钒基合金膜材料的研究现状,催化层对透氢性能的影响以及钒基合金膜的制备方法,并对未来的发展趋势进行了展望。 相似文献
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富银渣中的氯化银转化为单质银 总被引:1,自引:0,他引:1
铅阳极泥酸浸富银渣中的银呈氯化银状态。这种状态在下步火法熔炼时会造成损失,因此应首先转化为单质银。作者用置换法或碱处理法使氯化银转化为单质银,转化率95.4%-99.69%,银回收率〉99.9%。 相似文献
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采用熔铸和压力加工方法,研制出含少量稀土的新材料Ag-Sn-C??合金.该合金抗熔焊性强,灭弧能力好,电磨损少,温升低.在大功率微动开关和高寿命继电器的试验及应用中表明,新材料完全满足有关技术标准,其电接触性能优于其它银合金,在代替Ag-CdO及Au基合金的应用中结果良好. 相似文献
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电子组装用低银无铅焊料的研究进展 总被引:3,自引:0,他引:3
对目前国内外电子组装用低银无铅焊料最新的研究和应用情况进行了回顾和评述,介绍了低银无铅焊料的现状和其可靠性问题,以及国内外对几种低银无铅焊料进行的研究情况,最后着重分析和展望了低银无铅焊料研究应用的主要发展方向和趋势。 相似文献
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O. A. Kozaderov A. V. Dorokhov A. V. Vvedenskii 《Protection of Metals and Physical Chemistry of Surfaces》2012,48(4):411-418
Critical parameters of the morphological development of an electrode surface at the anodic oxidation of silver-based Ag-Pd alloys are estimated. Conditions (potential range and compositions of the alloy and electrolyte solution) of the true selective dissolution of the alloys in an acidic nitrate medium are determined. The nature and kinetic parameters of the nucleation step of the phase transformation of palladium in the surface layer of Ag4Pd and Ag8Pd alloys at the over-critical potentials are found. 相似文献
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A. B. Arbuzov V. A. Drozdov N. N. Leont’eva A. V. Shilova T. V. Kireeva M. V. Trenikhin A. V. Lavrenov 《Protection of Metals and Physical Chemistry of Surfaces》2016,52(4):653-657
A set of aluminum–nickel alloys has been studied. The elemental composition of the samples has been determined by atomic emission and atomic absorption spectrometry. X-ray diffraction analysis has revealed that the alloying of the metals leads to the formation of Al3Ni and Al3Ni2 intermetallic compounds, while a portion of Al remains in a metallic phase. The local chemical composition and surface morphology of the original alloys and the alloys activated with the liquid Ga–In eutectic have been studied by scanning electron microscopy and X-ray microanalysis. It has been shown that the original alloys are characterized by a pronounced morphological heterogeneity of interfacial regions in the near-surface layers. It has been found that the studied Al–Ni alloys are activated by the liquid Ga–In eutectic; however, one of the alloy components—the Al3Ni intermetallic compound—does not undergo significant morphological and chemical changes in contact with the liquid eutectic. 相似文献
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Three groups of brazing alloys were compared in brazing chemical-vapor-deposited (CVD) diamond, including two nickel-based
alloys (Ni-3Fe-7Cr-3B-0.5Si-0.02C and Ni-14Cr-10P-0.02C), one copper-based alloy (Cu-10Sn-15Ti), and two silver-based alloys
(Ag-5Cu-1Al-1.25Ti and Ag-34.25Cu-1In-1.75Ti). The nickel-based alloys catalytically transformed the sp3-bonded diamond into sp2-bonded carbon during high-temperature brazing operation though with the existence of Cr as the active metal. The bonding
strength was very low and the fracture primarily propagated through the sp2-bonded carbon. For Cu-10Sn-15Ti brazing alloy, the transformation of the sp3-bonded diamond into sp2-bonded carbon during high-temperature brazing operation was marginal. The bond strength was adequate and fracture took place
primarily through the brazing alloy bulk, due to the high concentrations of Sn and Ti that caused the precipitation of abundant
intermetallic compounds in the brazing alloy bulk. For Ag-based alloys having very low concentrations of Ti, no visible degradation
of diamond was observed and the bonding strength was very high. Crack primarily propagated through the brazed interface or
even the CVD diamond bulk. 相似文献
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多主元合金因其独特的微观结构和优异的综合性能而展现出了广阔的应用前景,也是近年来金属结构材料领域的研究热点之一。作为一类新型复杂合金,多主元合金与传统合金在原子尺度上存在本质的区别,其中局部化学短程有序作为多主元合金中一种特殊的原子级微观组织,其与位错的交互作用将对合金的变形行为及力学性能产生重要的影响。本文综述了多主元复杂合金中局部化学短程有序的相关研究进展,主要包括化学短程有序的形成因素、表征方法以及对位错行为和力学性能的影响,并针对目前关于化学短程有序的定量表征、调控技术、理论模型建立及对服役性能的影响等方面存在的问题与不足进行了分析和展望。 相似文献
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J. Antonowicz A. Pietnoczka W. Zalewski R. Bacewicz M. Stoica K. Georgarakis A.R. Yavari 《Journal of Alloys and Compounds》2011
We report on extended X-ray absorption fine structure (EXAFS) study of rapidly quenched Zr–Cu and Zr–Cu–Al glassy alloys. The local atomic order around Zr and Cu atoms was investigated. From the EXAFS data fitting the values of coordination number, interatomic distances and mean square atomic displacement were obtained for wide range of compositions. It was found that icosahedral symmetry rather than that of corresponding crystalline analogs dominates in the local atomic structure of Zr–Cu and Zr–Cu–Al amorphous alloys. Judging from bonding preferences we conclude that addition of Al as an alloying element results in considerable deviation from random mixing behavior observed in binary Zr–Cu alloys. 相似文献