过渡族金属二元合金固溶度理论的进一步研究

利用张邦维等提出的键参数函数和尺寸因素理论对过渡族２３个基体元素上的１５８７个二元合金困溶度作了进一步研究，发现仍然分别可以用抛物线ｙ１＝ａ－ｂｘ和椭圆将可溶元素和不可溶元素进行区分，且准确率高达８６．６％，９０％。同时，对抛物线参数ａ、ｂ和椭圆参数ｍ、ｎ、ｃ、ｄ进行了理论研究，同样发现这些参数与基体元素的特性参数存在很好的比例关系。     

METASTABLE EXTENSION OF SOLID SOLUBILITY OF RARE-EARTH ELEMENTS IN Al

The splat folis of Al-RE(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Er and Yb)binary alloys of 0.04—0.06 mm thickness were made by are-melting and hammer-anviltechnique,the.cooling rate is in 10~6 K/s order of magnitude.The metastable extendedsolid solubilities of these RE elements have been evaluated by measurements of the latticespacings of the rapidly solidified(RS)Al-RE alloys,they are 0.4,0.15,0.21,0.21,0.3,0.5,0.1,0.6,0.65,0.7,0.75,0.2 at.-% for above individual RE clements,respectively.Thesecondary phase in RS Al-RE alloys were identified to be Al_4RE for alloys containinglight RE and Eu elements and Al_3 RE for alloys containing heavy RE and Y elements.Some factors influencing the extension of solid solubility of Al-RE alloy were discussed.     

Electrochemical hydriding performance of Mg–TM–Mm (TM=transition metals,Mm=mischmetal) alloys for hydrogen storage

Eighteen as-cast binary Mg–Ni, Mg–Mm and ternary Mg–Ni–Mm and Mg–Ni–TM (TM=transition metals (Cu, Zn, Mn and Co); Mm = mischmetal containing Ce, La, Nd and Pr) alloys were hydrided by an electrochemical process to determine the alloys with the most potential for electrochemical hydrogen storage. The alloys were hydrided in a 6 mol/L KOH solution at 80 °C for 480 min and at 100 A/m². To assess the electrochemical hydriding performance of alloys, maximum hydrogen concentrations, hydrogen penetration depths and total mass of absorbed hydrogen in the alloys were measured by glow discharge spectrometry. In addition, the structures and phase compositions of the alloys both before and after hydriding were studied by optical and scanning electron microscopy, energy dispersive spectrometry and X-ray diffraction. It was determined that the highest total amount of hydrogen was absorbed by the Mg–25Ni–12Mm and Mg–26Ni (mass fraction, %) alloys. The maximum hydrogen concentrations in the Mg–25Ni–12Mm and Mg–26Ni alloys were 1.0% and 1.6%, respectively. The main hydriding product was the binary MgH₂ hydride, and the ternary Mg₂NiH₄ hydride was also detected in the Mg–25Ni–12Mm alloy. The electrochemical hydriding parameters achieved are discussed in relation to the structures of alloys, alloying elements and hydriding mechanisms.     

稀土元素在Al中固溶度亚稳扩展研究

采用锤—砧技术制备了厚0.04—0.06mm快速凝固Al—RE(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Er,Yb)合金箔试样,冷却速度达10~6K/s,用点阵参数法测得上述稀土元素在Al中亚稳扩展固溶度分别为0.4,0.15,0.21,0.21,0.3,0.5,0.1,0.6,0.65,0.7,0.75和0.2at.—%测定了Al—轻稀土(包括Eu)系中第二相是Al_4RE;Al—重稀土(包括Y)系中第二相是Al_3RE,原子尺寸因素是控制RE在Al中固溶度亚稳扩展的主要因素。     

Mg-La和Mg-Nd二元合金相稳定性的第一原理研究

La和Nd是镁合金中常用的稀土添加元素,为了帮助理解它们在Mg合金中的强化机制,应用第一原理计算方法,研究了Mg-La和Mg-Nd二元合金的相稳定性.计算结果表明,Mg-La和Mg-Nd合金在Mg₁₂RE和Mg₃RE之间的平衡相分别为Mg₁₇La₂和Mg₄₁Nd₅;La和Nd在Mg中的溶解度大小差别较大,表明者在镁合金中产生强化的机理不同;Mg₃Nd具有比Mg₁₂La更大的弹性模量,因而具有更好的强化效果.     

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.     

METASTABLE EXTENSION OF SOLID SOLUBILITY OF CERTAIN SIMPLE METALS OR METALLOIDS IN Ag

用点阵参数法研究了在熔体淬火条件下若干简单金属与类金属在Ag中固溶度的亚稳扩展。发现与Ag发生一系列包晶反应的二元合金的固溶度扩展符合电子浓度规律,并结合相图特征讨论了包晶系固溶度扩展的规律。简单共晶合金的固溶度扩展并不满足电子浓度规律,用Miedema理论解释了Si在Ag中固溶度低的原因。     

Fundamentals of the Physical Metallurgy of Uranium,Plutonium, and Their Alloys

Fundamentals of the physical metallurgy of uranium, plutonium, and other metals of the actinide series and alloys based on them created by A. A. Bochvar and developed by his disciples are presented.     

Transition Element Modifications of Al-Li

The development of aluminum-lithium metallurgy has led to alloys with unsurpassed combinations of density, specific strength, and specific modulus. This paper describes recent advances in the modification of aluminum-lithium binary alloys through additions of the Group IV-A transition metals (titanium, zirconium and hafnium). These elements lead to a duplex precipitation hardening behavior through the formation ofAlJLi and Al₃(TM,Li) (TM = transition element) which act as strengthening precipitates. The influence of the duplex structure on deformation mechanisms and the improvement of mechanical properties in these systems is illustrated by using results for the Al-Li-Zr system.     

依据活度系数预测二元合金熔体的表面张力

提出了一种简便的方法，以液态合金的活度系数为桥梁，假设体相和表面相的活度系数与其相应的原子配位数有一定的对应关系，从已有的热力学数据出发，利用Miedema二元合金生成热模型，借用数学软件，先计算出液态合金各个组元在体相中的活度系数，再将活度系数代入Butler方程求得二元合金的表面张力，并以Fe-Cu、Fe-Ni、Cu-Ni三种二元体系为例进行了计算验证，其结果与已有文献中的实验值吻合较好。     

Maximum solid solubility of transition metals in vanadium solvent

Maximum solid solubility （Cmax） of different transition metals in metal solvent can be described by a semi-empirical equation using function Zf that contains electronegativity difference, atomic diameter and electron concentration. The relation between Cmax and these parameters of transition metals in vanadium solvent was studied. It is shown that the relation of Cmax and function Zf can be expressed as In Cmax = Zf = 7. 316 5- 2. 780 5 （△X）^2- 71. 278δ^2-0. 855 56n^2/3. The factor of atomic size parameter has the largest effect on the Cmax of the V binary alloy; followed by the factor of electronegativity difference; the electrons concentration has the smallest effect among the three bond parameters. Function Zf is used for predicting the unknown Cmax of the transition metals in vanadium solvent. The results are compared with Darken-Gurry theorem, which can be deduced by the obtained function Zf in this work.     

铁锰二元合金耐液锌腐蚀机理

研究了四种不同Mn含量的铁锰二元合金在450℃液锌中的腐蚀行为,探讨了Mn对铁锌反应的影响规律。结果表明,铁锰二元合金在液锌中的腐蚀属于溶解性腐蚀。随着锰含量的增加,腐蚀速率有较大变化。含锰量为10wt%的合金,其腐蚀速率为5.79×10-3g.cm-2.h-1,含锰量为15wt%的合金,其腐蚀速率为3.64×10-2.gcm-2.h-1。锰含量为10wt%时,腐蚀产物由致密的δ相层和块状的ζ相层组成,致密的较厚的δ相层的存在,降低了铁锌反应速率,合金表现出较好的耐液锌腐蚀能力,而锰含量为15wt%时,腐蚀产物由大量疏松的颗粒状ζ相分布在液锌相中组成,疏松的组织恶化了合金的耐液锌腐蚀能力。     

MnFeNiCuPt and MnFeNiCuCo high-entropy alloys designed based on L10 structure in Pettifor map for binary compounds

Quinary exact equi-atomic MnFeNiCuPt and MnFeNiCuCo alloys were investigated to examine their formation of high-entropy alloys (HEAs) by focusing on an L1₀ structure from Pettifor map for binary compounds with 1:1 stoichiometry. The MnFeNiCuPt alloy was practically selected through computer-assisted alloy design under conditions of ≤ 20 at% noble metals, and the condition that the L1₀ structure appears as frequently as possible in the constituent binary equi-atomic compositions comprised of 78 elements. MnFeNiCuCo was selected by substituting Pt with Co from the MnFeNiCuPt alloy as the second candidate. X-ray diffraction and observations by scanning electron microscopy (by energy dispersive spectroscopy for composition analysis) revealed that as-prepared MnFeNiCuPt and MnFeNiCuCo alloys were formed into HEAs with dual fcc structures containing dendrites of ∼10 μm in width. The MnFeNiCuPt and MnFeNiCuCo alloys annealed at 1373 K for 43.2 ks and subsequently quenched in water formed single fcc phases and dual fcc phases, respectively. The annealed MnFeNiCuPt and MnFeNiCuCo alloys were subsequently cooled in a furnace and formed single L1₂ ordered phases and dual fcc phases, respectively. These phases, experimentally observed in the annealed samples, could be partially explained by thermodynamic calculations using Thermo-Calc with SSOL4 and SSOL5 databases for solid solutions. The MnFeNiCuPt and MnFeNiCuCo alloys exhibit soft magnetism with saturation magnetization of 0.23 and 0.43 T, respectively, with coercivity values of ∼1 kA m⁻¹. An alloy design for HEAs based on digitalized crystallographic data of these samples could lead to the discovery of new HEAs.     

Casting process and comparison of the properties of adapted load-sensitive magnesium alloys

Magnetic magnesium alloys can be utilized as a load sensitive material, in which the inverse magnetostrictive effect is used in order to measure the actual loads in structural components manufactured from such lightweight sensor alloys. To achieve a material which exhibits magnetic properties, Mg is alloyed with ferromagnetic materials like cobalt or samarium-cobalt. Alloying elements commonly used with Mg are utilized to improve the mechanical properties of these alloys, which however may have a slight negative impact on the magnetic sensitivity. In this work, two separate magnetic Mg alloys are compared, each with properties matched to the opposing requirements: (a) high load sensitivity and (b) satisfactory mechanical properties, respectively. The precipitation behavior of the ferromagnetic constituent Co in Mg together with other alloying elements is shown on the basis of SEM images. In addition, the dissolving behavior of the Co powder during the casting process of a binary Mg–Co alloy is investigated. Cyclic loading tests employing harmonic analyses of eddy current signals are utilized in order to verify the alloys’ sensory properties. The mechanical properties are investigated using tensile tests.     

用Wilson方程估算多元液态合金在给定温度下的组元活度

根据Ｗｉｌｓｏｎ参数与温度的关系，可将Ｗｉｌｓｏｎ方程扩展到只利用不同温度下测定的二元液太民合金各组元的活度，估算出给定温度下二元和多元液态合金各组元的活度，研究结果表明，多元液太民合金的活度算值与其实验数据和符合良好。     

掺V和Ag的TiAl合金中缺陷和电子密度的正电子湮没研究

测量了Ti50Al50，Ti50Al48V2，Ti50Al48Ag2合金和充分退火的Ti，Al，Ag，V金属的正电子寿命谱，利用正电子寿命参数分别计算了合金基体和缺陷态的自由电子密度。TiAl合金的脆性与其基体和晶界缺陷处的自由电子密度较低有关。在富Ti的TiAl合金中加入V，V原子比Al和Ti原子能提供较多的自由电子参与形成金属键，因而提高了合金基体和晶界缺陷处的自由电子密度；在TiAl合金中加入Ag也有类似的效应。在TiAl合金中加入V和Ag，有利于提高合金的韧性。     

The density of gold-silver-copper alloys and its calculation from the chemical composition

On the assumption that the contribution of a component metal to the density of an alloy is linearly related to the density and concentration of this metal in the alloy it is possible to calculate the values for the density of the system as a whole. Deviation from this behaviour occurs in the alloys formed by the metals of the copper group, and this is significant in the study of gold coins. Although the pure elements gold, silver and copper and their binary and ternary alloys crystallize mainly in the cubic face-centred form, the densities of these alloys do not display a linear correlation with the chemical composition (at%). This is due mainly to the effects of ordering and disordering in the alloys as is described in this paper.     

Calculation of thermodynamic quantities of metals and alloys by the statistical moment method

The thermodynamic properties of metals and alloys are studied using the moment method in the statistical dynamics, which allows us to take into account the anharmonicity of thermal lattice vibrations and size mismatch of constituent atoms, going beyond the quasi-harmonic approximation. Within the fourth-order moment approximation, the free energy and equilibrium lattice spacing of the binary alloys are given explicitly in terms of the effective pair potentials and the second- and fourth-order vibrational constants. The long-range order (LRO) parameter η and order-disorder transition temperatures (ODTs) T_c of binary alloys are obtained by solving the explicit transcendental equations. The numerical calculations of thermodynamic quantities for Cu₃Au and β-CuZn alloys show that the inclusion of the anharmonicity of lattice vibration plays an essentially important role in determining the phase stabilities of metals and alloys.     

Au与Au合金的微合金化

讨论和总结了Au与Au合金的微合金化.在Au合金中,微合金化元素的主要作用是强化、调整电阻率、细化晶粒尺寸和提高再结晶温度等. 几乎在所有的应用中,相对于Au具有大的熔点差或原子尺寸差的合金元素,诸如碱和碱土金属、稀土金属、高熔点金属、类金属和某些简单金属被选择作为微合金化元素. 介绍了微合金化Au合金的某些应用.许多微合金化元素对Au和Au合金性能的影响常常是多重和协同的.总结了对于不同应用的Au和Au合金的微合金化元素的某些选择原则.