Au-Ag-Y三元系富Au-Ag区域(Y≤34at%)的700℃等温截面

在Au-Ag、Au-Y和Ag-Y二元合金相图的基础上,采用X-射线衍射分析、电子探针等手段研究了Au-Ag-Y三元系中富金-银区域(Y≤34at%)的700℃等温截面.发现:在该截面的富金银侧沿着Au-Ag二元匀晶系存在一个单相区Au(Ag)或Ag(Au);在二元金属间化合物Au2Y和Ag2Y之间存在一个无限固溶体区域(Au2Y)或(Ag2Y).在该部分700℃等温截面上一共有6个单相区:Au(Ag) 或 Ag(Au)、Au6Y、Au51Y14、α(Au2Y) 或 (Ag2Y)、 Au3Y和 Ag51Y14;9个两相区:Au(Ag) Au6Y、 Au(Ag) Au51Y14、 Au(Ag) Au3Y、 Au(Ag) α(Au2Y)、 Au(Ag) Ag51Y14、Ag51Y14 α(Au2Y)、α(Au2Y) Au3Y、 Au3Y Au51Y14 和 Au51Y14 Au6Y;4个三相区: Ag51Y14 α(Au2Y) Au(Ag)、α(Au2Y) Au3Y Au(Ag)、 Au3Y Au51Y14 Au(Ag) 和 Au51Y14 Au6Y Au(Ag).在Au-Ag-Y三元系的该成分区域没有发现新的三元中间相.     

Au-Ag-Gd(Gd≤33.3%)三元系合金相图700℃等温截面

采用X射线衍射、DTA差热分析和显微金相分析等方法研究了Au—Ag—Gd三元系相图的富Au—Ag区域(Gd≤33．3％；原子数分数，下同)，测定了Au—Ag—Gd三元系部分相图的700℃部分等温截面。该截面上有6个单相区：(Ag，Au)，Ag51Gd14，Ag2Gd，Au2Gd,Gd14Au51和GdAu6；9个两相区：Ag51Gd14 (Ag,Au),Ag51Gd14 Ag2Gd,Ag2Gd Gd14Au51,(Ag,Au) AusGd,Ag2Gd Au2Gd,(Ag,Au) Gd14Au51,Ag51Gd14 Au2Gd,Gd14Au51 GdAu6和(Ag,Au) GdAu6;4个三相区：（Ag,Au) Gd14Au51 Au2Gd,Ag51Gd14 (Ag,Au) Au2Gd,Ag51Gd14 Ag2Gd Au2Gd和(Ag,Au) GdAu6 CdAu6 Gd14Au51。在该成份区域未发现新的三元化合物。     

富金的Au-Ag-Zr三元合金研究

在Au-Ag、Au-Zr和Ag-Zr二元系相图研究的基础上,采用X射线衍射分析、电子探针(EPMA)和显微金相方法测定了Au-Ag-Zr三元系富金区域的700℃等温截面.发现在该等温截面上的富Au-Ag侧,沿着Au-Ag二元匀晶系存在一个长条形的单相区Au(Ag)或Ag(Au),确定在该部分等温截面上共有4个单相区:固溶体Au(Ag)或Ag(Au)、Au4Zr、Au3Zr和Au2Zr;4个二相区:Au4Zr Au(Ag)、Au3Zr Au(Ag)、Au4Zr Au3Zr和Au3Zr Au2Zr;2个三相区:Au4Zr Au3Zr Au(Ag)和Au3Zr Au2Zr Au(Ag);在该区域没有形成新的三元化合物.     

Partial phase diagram of Au-Ag-Dy ternary system

On the basis of Au-Ag, Au-Dy and Ag-Dy binary phase diagrams, the 700 ℃ isothermal section of Au-Ag-Dy ternary system（Dye≤35 %, mole fraction） was established by X-ray diffraction analysis, differential thermal analysis and optical microscopy. It is found that there is a long single-phase region, Au（Ag） or Ag（Au）, along the Au-Ag binary isomorphous system on the gold-silver-rich side of the 700 ℃ isothermal section and between the binary compound Au2Dy and Ag2 Dy there is the all proportional solid solution, （Au2 Dy） or （Ag2 Dy）. It is confirmed that the partial 700 ℃ isothermal section consists of six single-phase regions： solid solution Au（Ag） or Ag （Au）, （Au2 Dy） or （Ag2 Dy）, Au6 Dy, Au51 Dy14, Au3 Dy and Ag51 Dy14 ; nine binary-phase regions; （Au2 Dy） ＋ Au （Ag）, Au6Dy＋ Au（Ag）, Au（Ag） ＋Ag51 Dy14 , Ag51 Dy14 ＋ （Au2Dy）, Au3Dy＋（Au2Dy）, Au3Dy＋ Au51 Dy14, Au51 Dy14＋Au6Dy, Au51 Dy14＋Au（Ag） and Au（Ag） ＋Au3Dy; four ternary regions： Ag51 Dy14＋ （Au2Dy）＋ Au （Ag）, （Au2 Dy） ＋ Au（Ag） ＋ Au3 Dy, Au（Ag） ＋ Au3 Dy＋ Au51 Dy14 and Au51 Dy14＋ Au （Ag）＋ Au6 Dy. No new ternary compound is formed in the gold-silver-rich field（Dy≤35 %） of the Au-Ag-Dy ternary system.     

用碘化钾滴定金基和钯基合金中的银

研究了在氨性介质中以碘化钾为滴定剂使用各种指示电极检测终点电位滴定银,讨论外来离子的干扰影响.提出以Ag—AgI指示电极(vs、SCE)、不经分离直接测定银的方法.方法适用于Au—Ag—Cu、Au—Ag—Cu—Gd、Pd—Ag、Pd—Ag—Cu—Au—Pt—Zn等合金中银的分析.     

基于FIB/SEM切片和TEM/EELS技术分析Au/Ag泡沫材料的微观结构

利用FIB/SEM切片、XRD、TEM和EDX、EELS等先进分析技术对微球模板法所制备的Au/Ag泡沫材料的微观结构、形貌、成分及成分分布等进行了细致的研究。结果表明:由微球状Au/Ag球壳堆积而成的泡沫材料中微球直径约8 m,微球壁厚200～1200 nm;Au/Ag泡沫材料的球壳可细分为3层,内层和外层为Au/Ag合金的微粒,中间主要是非晶碳层,夹杂有少量的Au/Ag微粒;Au/Ag泡沫材料的骨架由单个空心球壳组成,球壳之间通过接触点的金属镀层连接在一起;球壳上有小孔状结构,是在热分解法去除聚苯乙烯微球模板时形成的;球壳壁厚分布不均匀,少数球壳有塌陷、变形、破裂等现象。这些详细的分析有助于改进工艺,提高Au/Ag泡沫材料的制备质量。     

金银纳米粒子-稀土氧化物复合薄膜的光吸收特性

在真空中用蒸发沉积的方法制备了埋藏有Ag或Au纳米粒子的稀土氧化物复合薄膜：Ag—La2O3、Ag—Nd2O3、Ag-Sm2O3、Au—La2O3、Au—Nd2O3和Au—Sm2O3。通过光吸收实验研究，发现这些薄膜都在光波长310-1200nm内出现吸收峰，Ag纳米粒子—稀土氧化物薄膜和Au—Sm2O3薄膜的光吸收峰位置随Ag或Au粒子粒径和数量的增加产生红移；而Au—La2O3和Au-Nd2O3薄膜的光吸收随Au量的增大变为金属性光吸收。分析表明，Ag或Au粒子与稀土氧化物之间的相互作用是影响光吸收峰位置的主要原因。     

BaO对单Pd催化剂净化甲醇燃料车尾气性能的影响

利用FIB/SEM切片、XRD、TEM和EDX、EELS等先进分析技术对微球模板法所制备的Au/Ag泡沫材料的微观结构、形貌、成分及成分分布等进行了细致的研究.结果表明:由微球状Au/Ag球壳堆积而成的泡沫材料中微球直径约8 μm,微球壁厚200～1200 nm; Au/Ag泡沫材料的球壳可细分为3层,内层和外层为Au/Ag合金的微粒,中间主要是非晶碳层,夹杂有少量的Au/Ag微粒;Au/Ag泡沫材料的骨架由单个空心球壳组成,球壳之间通过接触点的金属镀层连接在一起;球壳上有小孔状结构,是在热分解法去除聚苯乙烯微球模板对形成的;球壳壁厚分布不均匀,少数球壳有塌陷、变形、破裂等现象.这些详细的分析有助于改进工艺,提高Au/Ag泡沫材料的制备质量.     

氰化浸出-电积法从铜阳极泥提取金和银

采用硫酸化焙烧、稀硫酸浸出铜－－氰化浸出、电积提取Au和Ag－－还原熔炼回收Pb、Bi、Sn和微量Au、Ag工艺处理铜阳极泥，具有流程简短,回收率Au≥99%,Ag≥99%,Cu、Pb、Bi、Sn综合利用好等优点。     

黑色岩系中贵金属八元素同时测定

黑色岩中含有大量有机碳,贵金属元素又呈超微细分散状态,难以识别,传统的镍锍试金方法难于测定。以锡作捕集剂,通过调整试金配料,提高熔融温度,增加助熔剂和覆盖剂等方式,建立了锡试金富集—ICP-MS法同时测定黑色岩中8个贵金属元素的方法。方法检出限(ng/g)为:Ag27.8,Au、Pd 0.11,Pt 0.10,Rh、Ru、Ir、Os均为0.02;各元素的回收率为88%~120%,可用于黑色岩系及其它岩石矿物中贵金属元素的测定。     

合金元素对Zr基大块非晶晶化行为的影响

利用准晶的共轭结构模型构造出了Zr基非晶合金中准晶相的原子结构模型,用递归方法研究了合金元素对非晶晶化过程的影响.结果表明:Zr基非晶合金析出的准晶相存在Zr6Ni,Ni6Zr2种结构,Ni6Zr结构优先析出;合金元素Ag,Pd,Pt,Au固溶于准晶中时,占据Cu,Ni原子的位置,增大近邻原子间的相互作用,这从电子理论角度解释了合金元素Ag,Pd,Pt,Au稳定地促进二十面体准晶(I)相析出的事实.     

Surface enoblement by dissolution of Cu,Ag and Zn from single phase gold alloys

Single phase alloys with 30 at.% Au and with different proportions of Ag, Cu and Zn as additional alloying elements have been investigated with regard to selective dissolution. Measurements of rest potentials and ESCA analyses show that Cu and Zn are preferentially dissolved in aqueous solutions of chloride and small concentrations of sulphides leaving behind a surface significantly enriched in Au with a thickness of approximately 1 nm. No significant selective dissolution of Ag was observed in the solutions investigated. Only alloys containing substantial amoungs of Ag tended to become tarnished in sulphur containing solutions. It is suggested that Ag₂S is more easily formed than sulphides of Cu and Zn because also other oxidative reactions to oxides/ hydroxides of these elements take place, which is not the case for Ag. These oxides/hydroxides of Cu and Zn dissolve into the solution creating an Au-surface enrichment also in the diluted sulphide-containing solutions.     

倒装LED回流焊接头组织的抗高温时效性能

以SAC305锡膏为钎料,通过回流焊实现了倒装LED与Cu/Ag、Cu/Ni/Au基板的互连.研究了两种接头界面微观组织在高温时效条件下的演变行为.结果表明,接头两侧界面组织间存在相互影响. Cu/Ni/Au基板中的Au在回流焊过程中溶解至体钎料内,对芯片侧Au-Sn金属间化合物的生长起到抑制效果.芯片侧Au-Sn金属间化合物的快速生长降低了体钎料中Sn的相对浓度,从而使体钎料中有利于基板侧IMC生长组元的相对浓度得到提升,促进基板侧IMC生长.相比较而言,在Cu/Ag基板上的回流焊试样抗高温时效性能较差.     

Phase equilibria in the Ag–Au–Bi ternary system

The aim of the action of Cost 531 taking into account the 11 elements: Ag, Au, Bi, Cu, In, Pb, Sb, Sn, Zn (solder), Ni and Pd (substrate) is the database assessment of candidates for lead free soldering process. Among those elements, we chose to study three of them forming the ternary Ag–Au–Bi system. We have determined its phase diagram using X-ray powder diffraction, differential scanning calorimetry and electron probe micro-analysis. Four vertical sections (isopleths) were studied at 20 at.% Ag, 50 at.% Bi, 85 at.% Bi and the section with ratio Ag:Au = 1:4. The results give one transitory peritectic reaction and an extremely large primary crystallization area, L + , restricting thus the two others reactions (L + (Bi) and L + Au₂Bi). Schematic representations of the ternary equilibria are given.     

混合稀土对金银铜合金组织及硬度的影响

为研究混合稀土元素在金银铜合金内部的分布状态以及混合稀土元素的添加对金银铜合金硬度的影响,使用真空中频感应炉制备了Au-35Ag-5Cu、Au-35Ag-5Cu-1RE合金,并对铸态合金进行不同变形量的轧制加工,探讨了稀土元素的添加、变形量对合金组织及维氏硬度的影响。使用EDS进行了稀土元素分布检测、DSC分析固液相线温度并进行维氏硬度的测量等。结果表明,稀土元素La、Ce、Pr、Nd占据了Au、Ag元素的位置,改变了AuAg两种元素的分布,与Cu固溶效果较好,对Cu元素分布没有显著影响。稀土元素的添加降低了Au-35Ag-5Cu的液相线温度和固相线温度,增大了液相线温度和固相线的温度差。混合稀土元素的添加有助于提高铸态及轧制态金银铜合金的耐磨性。     

Effects of noble metal addition on microstructure and thermoelectric properties of NaxCo2O4

The synthesis of Na_xCo₂O₄/Ag and Na_xCo₂O₄/Au composites was tried by mechanical milling and subsequent sintering. Ag and Au particles were added to the Na_xCo₂O₄ powder prior to the mechanical milling. The microstructure and thermoelectric properties of the Na_xCo₂O₄/Au composite were compared to those of the Na_xCo₂O₄/Ag composite and the Na_xCo₂O₄ single phase, and the effects of the Ag and Au addition on the thermoelectric performance of Na_xCo₂O₄ were discussed. Au particles around 2 μm or smaller in size, which were significantly smaller than Ag particles around 10 μm in size, were dispersed in the Na_xCo₂O₄ matrix. The Seebeck coefficient and the electrical resistivity of Na_xCo₂O₄ were slightly enhanced and significantly reduced by these noble metals addition, resulting in the large power factor of these composites. On the other hand, the Na_xCo₂O₄/Au composite showed the electrical resistivity larger than that of the Na_xCo₂O₄/Ag composite. Ag and Au addition markedly increased the thermal conductivity, and the dimensionless figure of merit of Na_xCo₂O₄ could not be improved by these noble metals addition.     

Theoretical research on vacuum separation of Au−Ag alloy

To provide an accurate prediction of the product component dependence of temperature and pressure in vacuum distillation and give convenient and efficient guidance for the designing of the process parameters of industrial production, according to the molecular interaction volume model (MIVM), the separation coefficient (β) and vapor?liquid equilibrium composition of Au?Ag alloy at different temperatures are calculated. Combined with the vapor?liquid equilibrium (VLE) theory, the VLE phase diagrams, including the temperature?composition (T?x) and pressure?composition (p?x) diagrams of Au?Ag alloy in vacuum distillation are plotted. The triple points and condensation temperatures of gold and silver vapors are calculated as well. The results show that the β decreases and the contents of gold in vapor phase increase with the distillation temperature increasing. Low pressures have positive effect on the separation of Ag and Au. The difference between the condensation temperatures of gold and silver is about 450 K in the pressure range of 1?10 Pa.     

ICP-AES法分析富银渣

试样用HNO3与HCl溶解,ICP-AES法直接测定富银渣中0.01%～5%的Ag、Au、Cu、Ni、Sb、Bi、Zn、Al、As、Sn等元素.研究了溶剂、试样中铅及其它共存元素的干扰,选择了合适的分析线.加标回收率在99.6%～107.1%,相对标准偏差为0.59%～3.08%,方法准确、简便、快速.     

Relationship between the types of binary alloy phase diagrams of VIII and IB group elements and the Mendeleev numbers

The relationship between the types of binary alloy phase diagrams of Vlll and IB group elements and the Men deleev numbers was discussed for the first time using the Vlll and IB group elements as solvent metals (A) and the other elements as solute metals (B), basesd on their alloy phase diagram types. The Mendeleev numbers of the solvent metals and the solute metals were expressed as Ma and MB, respectively. A two-dimension map of MdMB was drawn. It is indicated that there is an oblique line in the map, which divides the binary alloy phase diagram types of solvent metals into two symmetry parts, the phase diagram types of the other elements with solvent metals located at the above or down of the line respectively, while on the line, AM= 0. The phase diagrams between the solvent metals basically are simple systems, mainly belong to the types of continues solid solution and the peritectic (about 40% for each type). The solvent metals can be divided into three groups: Co, Ir, Rh, Ni, Pt, and Pd as the first group; Ag, Au, and Cu as the second group;and Fe, Os, and Ru as the third group. The characteristics of the phase diagrams formed between the elements in each group were discussed. About 80% phase diagrams belong to complex systems and less than 20% belong to the simple systems. The regular variation of the chemical scale, the metallic radii of the atoms, the number of valence electrons, and the first ionization energy with the Mendeleev numbers and the crystal structure were introduced as well.