Thermodynamic assessment of Sb–Sn system

Abstract

The Sb–Sn system has been assessed in terms of thermodynamic models for the individual phases. Expressions for the Gibbs energy as a function of temperature and composition are obtained and both phase diagram and thermochemical data are calculated and found to be in good agreement with the experimental data. The compound phase SbSn is treated by means of a Bragg–Williams–Gorsky approach.

MST/421     

HCD法测定纯镍中As,Sb,Pb,Sn,Bi含量的研究

纯镍中杂质元素Ａｓ,Ｓｂ ,Ｐｂ ,Ｓｎ ,Ｂｉ等的含量对其本身的性能和由其冶炼的合金的性能有着很大的影响 ,因此准确测定纯镍中这些杂质元素的含量具有重要意义。采用空心阴极光谱法测定纯镍中杂质元素的含量具有灵敏度高、稳定性好、用料少等优点 ,由于不需要经过化学处理 ,减少了被污染的机会。试验方法为称取金属颗粒样品 ,装入石墨电极中 ,在光栅光谱仪上 ,以空心阴极光源为激发源 ,在氩气气氛中进行放电 ,经光栅摄谱仪分光成像后 ,记录于感光板上 ,在测微光度计上测出待测元素的谱线黑度 ,在工作曲线上查得待测元素的百分含量。试样…     

掺Sb,Sn和Cd的In2O3的电性研究

本文研究了掺杂Sb、S_n及Cd的In_2O_3的电性质,并与纯的In_2O_3进行比较,得到一些有意义的结果。IO的电导率及载流子浓度主要由氧缺位所致;ITO和ISO的电导率和载流子浓度,主要由掺杂元素所致;掺Sn的电导率、载流子浓度和迁移率高于掺Sb,其原因在于在同样掺杂浓度的条件下,ITO中的中性杂质浓度低于ISO及掺Sn后使电子离域程度增大。在掺Cd浓度高时,随着Cd浓度增加,电导率和载流子浓度均降低。     

Glass-formation region of ternary Sn–Sb–Se-based chalcogenide glasses

Tin-antimony-selenium (TAS)-based system belongs to the ternary chalcogenide compounds of IV-V-VI group owing to their heavy elemental masses, their glass formation region was assumed to be small comparing to their counterpart elements in the same group. However, there were rare published reports on their glass structure, while their glass boundary formation region was not yet reported. It was the aim of this paper to map their glass-forming region experimentally using XRD and validate it theoretically using the average co-ordination number, , and the fraction of the bond distributions, f, from chemical order model. Theoretically, it was validated that the glass formation was arrested between 2.4 and the fraction of Sn–Se bonds, f_Sn–Se < 44.5%. XRD analyses of 66-as-prepared samples revealed that the glass formation region was located within the predicted area that mapped in structural triangle.     

Electrical conductivity and viscosity of liquid Sn–Sb–Cu alloys

Tin-antimony-copper alloys are under intense consideration as favourable lead-free solders for consumer electronics and telecommunications. The electrical conductivity and viscosity studies were carried out in a wide temperature range above the liquidus. A melting-solidification region was investigated by Differential Scanning Calorimetry (DSC). The scaling relations have been proposed. A comparison with data available in literature is given.     

Sn(Sb)O2凝胶结构模型及试验研究

对Sn(Sb)O2干凝胶的结构进行了试验及模拟研究，通过BET－N2吸附及XRD分析，详细研究了SnO2凝胶在200－600℃干燥过程中凝胶骨架纳米结构及其变化规律，并研究了掺杂元素Sb对纳米结构演变的影响。研究发现：SnO2干凝胶为1－10nm的纳米多孔结构，其结构特征符合圆柱体通孔模型；随着固化温度的升高，凝胶骨架粗化，但结构特征相似性不变，孔体积率也基本不变；Sb的增加有细化骨架的作用。     

Microstructure,mechanical properties,and deformation behavior of Sn–1.0Ag–0.5Cu solder after Ni and Sb additions

Minor alloying addition to solders has been an important strategy to improve the integrity and reliability of Pb-free solders joint. In this study, the effects of 0.06Ni and 0.5Sb additives on the microstructure and solidification behavior as well as the creep properties of Sn–1.0Ag–0.5Cu (SAC105) alloys were investigated. Results show that alloying of Ni and Sb resulted in considerably reduced undercooling, increased eutectic area and extended volume fraction of proeutectic Sn of which the dendritic size was refined. Moreover, with the addition of Ni and Sb into SAC105, significant improvement in creep resistance of (210%) and (350%) is realized when compared with the SAC105 solder alloy. Likewise, the creep life time of SAC105 alloys was remarkably enhanced (2–3 times) with the minor alloying additions. An analysis of the creep behavior at elevated temperatures suggested that the presence of hard Ni₃Sn₄ IMC particles and the solid solution hardening effects which appeared, respectively, in the Ni-doped and Sb-doped alloys could increase the resistance to dislocation movement, which improves the creep properties.     

Impression creep of Sn–40Pb–2·5Sb peritectic solder alloy

Abstract

The power law creep behaviour of the Sn–40Pb–2·5Sb peritectic solder alloy was investigated using an impression test apparatus. The tests were carried out under constant stress in the range 17 to 39 MPa and at temperatures in the range 296 to 363 K. Assuming a power law relationship between the impression velocity and stress, power law stress exponents in the range 1–3 were determined. Analysis of the data showed that for all loads and temperatures, the activation energy was stress independent with values in the range 51–56 kJ mol^-1. Based on the stress exponents obtained and activation energy data, it is proposed that grain boundary diffusion is the major mechanism for creep of the Sn–Pb–Sb peritectic alloy under these test conditions.     

Sb,Bi 元素对 Sn-22 Sb 高温钎料合金组织的影响

目的研究Sb和Bi元素对Sn-22Sb钎料显微组织的影响。方法制备了(Sn-22Sb)-xBi和Sn-xSb钎料合金,并分别采用差热分析和X射线衍射仪,分析了材料的熔化特征和物相。结果结果表明:Sn-22Sb钎料合金主要由灰色的β-Sn和白色块状的Sb2Sn3构成;少量的Bi使得Sn-22Sb钎料合金中Sb2Sn3金属间化合物逐渐细化和均匀化,数量却急剧增加;大量添加Sb后,使得Sn-22Sb钎料合金几乎全部变为粗大的块状β-SnSb组织,钎料合金的开始熔化温度有所提高。结论通过添加其他合金元素,降低Sn-50Sb钎料液相线温度,使其有望应用于二次回流焊。     

基于Sn掺杂Ge2Sb2Te5的相变存储器器件单元存储性能

采用0.18μm标准工艺制备出基于Sn掺杂Ge2Sb2Te5相变材料的相变存储器器件单元,利用自行设计搭建的电学测试系统研究了其存储性能.结果表明:Sn的掺杂没有改变Ge2Sb2Te5的相变特性,其相变阚值电压和阈值电流分别为1.6V和25μA;实现了器件单元的非晶态(高阻)与晶态(低阻)之间的可逆相变过程;器件单元中相变材料结晶所需电流最低为1.78mA(电流宽度固定为100ns)、结晶时间大于80ns(电流高度固定为3mA);相变材料非晶化脉冲电流宽度为30ns时,所需电流大于3.3mA;与Ge2Sb2Te5相比,Sn的掺杂降低了SET操作的脉冲电流宽度,提高了结晶速度,有利于提高相变存储器的存储速度.     

Influence of small Sb nanoparticles additions on the microstructure, hardness and tensile properties of Sn–9Zn binary eutectic solder alloy

In the present study, different weight percentages of Sb nanoparticles (100–120 nm) ranging from 0 to 1.5 wt% were added to Sn–9Zn eutectic solder alloy to investigate the effect of third element addition on the microstructure, mechanical properties as well as thermal behavior of the newly developed composite solder alloys. The results indicate that the Sb nano-particle based intermetallic compounds (IMC) were found uniformly distributed, refined the microstructure and formed IMC particles in the eutectic solder alloy. After the addition of nano Sb particles in Sn–9Zn solder, fine α-Zn phase and ε-Sb₃Zn₄ IMC particles were clearly observed in the β-Sn matrix. The ε-Sb₃Zn₄ IMC particles were uniformly distributed in the β-Sn phase, which resulted in an increase in the tensile strength due to the second phase dispersion strengthening mechanism. However, in the doped Sn–9Zn/1.5Sb alloys, α-Zn phases were broken enormously, depleted and round shaped compared to the normal rod shaped α-Zn phase microstructure in plain Sn–9Zn solder. In comparison, the ε-Sb₃Zn₄ IMC particle in the doped Sn–9Zn/1.0Sb alloy were star shaped. The average tensile strength and micro-hardness of the Sb doped Sn–9Zn solder alloys were consistently higher than the plain un-doped Sn–9Zn solder. The tensile strength and the microhardness increased with increasing Sb nano-particle content, up to 1.0 wt% of Sb content, and then decreased beyond that threshold value. Consequently the percentage (%) elongation of the Sb nanoparticle doped Sn–9Zn solder decreased with increasing Sb nano-particle content, up to 1.0 wt% of Sb content, and then increased beyond that threshold value.     

Creep of Pb–2·5Sb–0·2Sn alloy at low stresses

Abstract

The creep of a Pb–2·5Sb–0·2Sn alloy has been studied at stresses up to 6·5 MN m^?2 in the temperature range 318–348 K (0·53–0·58T_m) using helical specimens. At 333 K, a transition in the stress exponent from ~1 to 3 occurred at ~3 MN m^?2. The observed good agreements below the transition stress, both for experimental dE/do and predictions for Coble diffusional creep of lead, and for measured activation energy for creep and the activation energy for grain boundary self-diffusion in lead, suggest that grain boundary diffusional creep is the dominant mechanism. at low stresses. The presence of antimony does not seem to affect the magnitude of dE/do appreciably, and the results suggest that the grain boundary self-diffusivity of lead is not influenced by the presence of segregated antimony on the grain boundaries. The diffusional creep occurred above a threshold stress of magnitude ~0·5 MN m^?2, and its temperature dependence was characterised by an activation energy of ~20 kJ mol^?1, similar to the value of 23 ± 7 kJ mol^?1 typical of pure metals in the temperature range investigated. The stress exponent of ~3 observed for the power law regime suggests control by viscous glide of dislocations constrained by dragging of solute atmospheres. Preliminary tests on sagging beam specimens of as-worked material at an applied stress of 2·5 MN m^?2 and a test temperature of 333 K has provided the first direct evidence that anisotropic grain shape affects Coble creep. The specimen with the longest grain dimension along the stress axis underwent slower creep than the specimen with the longest grain dimension perpendicular to the stress axis. This observation is in qualitative agreement with theoretical predictions.

MST/1139     

ICB 淀积 Sb,Pb 的薄膜结构

本文用离化原子团束工艺淀积 Sb 和 Pb 薄膜,系统研究了各淀积参数对薄膜晶粒取向度等结构特性的影响,并测定了 Pb 原子团束的原子团大小和离化率,讨论了薄膜结构的形成机理.     

煅烧温度对Sn(Sb)O2包覆TiO2导电粉性能的影响

采用共沉淀法在亚微米级二氧化钛表面包覆Sn(Sb)O2,制得二氧化钛导电粉.用XRD、XPS、TG-DSC等测试手段对粉体进行了分析,讨论了不同煅烧温度对导电二氧化钛粉体的表面元素的变化、物相、体积电阻率的影响及原因.     

新型复合钙钛矿Ba(SbⅢ,SbⅤ)O3的水热合成和表征

采用水热晶化法制备了Ｂａ（Ｓｂ^Ⅲ,Ｓｂ^Ⅴ）Ｏ_３新型钙钛矿型氧化物,并通过ＸＲＤ、 ＩＲ、ＳＥＭ和ＩＣＰ等方法对产物物相、形貌和组成等进行了表征．结果表明,产物为立方钙钛矿结构,晶胞参数为α＝０．４１５ｎｍ,粒度为１～２μｍ具有一定团聚的多晶粉末．产物中锑为三价和五价两种价态．水热条件对合成影响的研究结果表明, Ｂａ（Ｓｂ^Ⅲ,ｓｂ^Ⅴ）Ｏ_３合成的适宜碱度和ｎ_{Ｓｂ（Ⅴ)}／ｎ_{Ｓｂ（Ⅲ）}分别为 ８～１０Ｍｏｌ／Ｌ ＫＯＨ和 ０～１     

Sn,Al对船用铜管耐蚀性的影响

研究了铜及Cu-2.80%Sn-1.06%Al合金在3.0%NaCl溶液及流动海水中腐蚀性能,利用金相、扫描电镜及电化学特征分析了它们的耐蚀特性。结果表明,纯铜在21mV时发生阳极溶解,在海水冲刷作用下保护膜很快遭到破坏,腐蚀速度大,Cu-2.80%Sn-1.06%Al合金由于其表面形成的Cu、Sn和Al的混合氧化物保护膜均匀、致密、质硬、在流动海水冲刷、摩擦作用下,保护膜稳定性好,腐蚀速度小。     

Interfacial interaction of solid cobalt with liquid Pb-free Sn–Bi–In–Zn–Sb soldering alloys

Dissolution kinetics of cobalt in liquid 87.5%Sn–7.5%Bi–3%In–1%Zn–1%Sb and 80%Sn–15%Bi–3%In–1%Zn–1%Sb soldering alloys and phase formation at the cobalt–solder interface have been investigated in the temperature range of 250–450 °C. The temperature dependence of the cobalt solubility in soldering alloys was found to obey a relation of the Arrhenius type c _s = 4.06 × 10² exp (−46300/RT) mass% for the former alloy and c _s = 5.46 × 10² exp (−49200/RT) mass% for the latter, where R is in J mol⁻¹ K⁻¹ and T in K. For tin, the appropriate equation is c _s = 4.08 × 10² exp (−45200/RT) mass%. The dissolution rate constants are rather close for these soldering alloys and vary in the range (1–9) × 10⁻⁵ m s⁻¹ at disc rotational speeds of 6.45–82.4 rad s⁻¹. For both alloys, the CoSn₃ intermetallic layer is formed at the interface of cobalt and the saturated or undersaturated solder melt at 250 °C and dipping times up to 1800 s, whereas the CoSn₂ intermetallic layer occurs at higher temperatures of 300–450 °C. Formation of an additional intermetallic layer (around 1.5 μm thick) of the CoSn compound was only observed at 450 °C and a dipping time of 1800 s. A simple mathematical equation is proposed to evaluate the intermetallic-layer thickness in the case of undersaturated melts. The tensile strength of the cobalt-to-solder joints is 95–107 MPa, with the relative elongation being 2.0–2.6%.     

245摩擦材料中Pb,Sn,Mo的原子吸收光谱测定

本文采用原子吸收光谱法(AAS)测定245摩擦材料中的Pb、Sn、Mo。优选了原子吸收测量条件,研究了基体Fe及其共存元素对待测元素的影响。编制了分析方法。本法与化学法同时分析同一样品,t检验结果表明,两种方法分析的结果在统计上无显著差异,表明本法不仅简便快速而且准确可靠。