scholarly journals The constitution of the aluminium-rich aluminium-cobaltcopper alloys, with special reference to the role of transitional metals in alloy formation

1949 ◽  
Vol 197 (1050) ◽  
pp. 321-335 ◽  
Keyword(s):  
Solid Solution ◽  
Ternary Compound ◽  
Copper Alloys ◽  
Primary Crystallization ◽  
Alloy Formation ◽  
Atom Ratio ◽  
Transitional Metals ◽  
Ternary Compounds ◽  
Electron Atom

An experimental investigation of aluminium-rich aluminium-cobalt-copper alloys has shown that, as in the alloys of alumiinium and copper with nickel and iron respectively, a ternary compound, in addition to the phases Co 2 Al 9 and CuAl 2 , enters into equilibrium with the primary solid solution. Isothermal sections of the ternary model have been established at 530° and 500° C; the field in which the solid solution, α , and the ternary compound, T (CoCu), are in equilibrium is very narrow, while the ( α + Co 2 Al 9 ), ( α + Co 2 Al 9 + T (CoCu)) and ( α + T (CoCu)+CuAl 2 ) phase fields are relatively extensive. The presence of T (CoCu), and its formation peritectically from Co 2 Al 9 , have been confirmed by further experiments on solid and semi-liquid alloys and, from the examination of slowly cooled alloys, the appropriate fields of primary crystallization have been determined. The composition range in which T (CoCu) separates as primary crystals is restricted, and, for this and other reasons, pure samples of T (CoCu) cannot be obtained for analysis. Extrapolation of the accurately established ( α + T (CoCu) + CuAl 2 )/( α + T (CoCu)) and ( α + T (CoCu) + CuAl 2 )/( T (CoCu) + CuAl 2 ) boundaries, however, showrs that the homogeneity range of T (CoCu) includes the composition Co 2 Cu 5 Al 16 . The solubility of copper in Co 2 Al 9 does not exceed 1·44% at 570° C. In discussion, it is showm that the ternary compounds NiCu 3 Al 6 and FeCu 2 Al 7 occur at the same electron: atom ratio, according to the authors’ theory of the role of transitional elements in alloy formation. The compound T (CoCu) forms a third member of the same series and is probably of the ideal composition Co 2 Cu 5 Al 13 . The results support the hypothesis of absorption of electrons by transitional metal atoms present in aluminium-rich alloys, and also that the occurrence of ternary compounds is influenced to a marked degree by the electron: atom ratio.

Intermetallic compounds in ternary aluminium-rich alloys containing transitional metals

1951 ◽  
Vol 205 (1080) ◽  
pp. 103-118 ◽  
Keyword(s):  
Ternary Compound ◽  
Solid Solutions ◽  
Atom Ratio ◽  
Atomic Orbitals ◽  
Transitional Metals ◽  
Ternary Compounds ◽  
Iron Silicon ◽  
Electron Atom ◽  
Transitional Metal ◽  
Silicon System

Several investigations have now been made of the constitutions of ternary aluminium-rich alloys containing transitional metal solutes. Consideration of the results obtained has led to the conclusion that in aluminium-rich alloys, the transitional metal atoms may accept electrons from the structure as a whole, and that the ternary compounds formed have many of the characteristics of electron compounds. Although the acceptance of electrons may be understood in terms of the completion of the 3 d band of the transitional metal, consideration of the Brillouin zone structures of Co 2 Al 9 , Co 2 Al 5 and NiAl 3 suggests, empirically, that the numbers of electrons accepted per atom are greater than the band theory would indicate, and are more nearly equal to the vacancies in the 'atomic orbitals’ postulated in the Pauling theory of transitional metals. Further information with regard to the alloying characteristics of transitional metals has been sought by investigating ternary alloys of aluminium and silicon with chromium, manganese, iron, cobalt and nickel. The results are discussed in the present paper. Assuming acceptance of electrons by the transitional metals to extents given by the vacancies in the 'atomic orbitals’ postulated by Pauling, it is found that the ternary compound of higher electron: atom ratio in the aluminium-chromium-silicon system has a similar electron concentration to that of the ternary compound of lower electron: atom ratio in the aluminium-manganese-silicon system. This behaviour is repeated for the systems aluminium-manganese-silicon and aluminium-iron-silicon; in this case the compounds involved (α(AlFeSi) and α(AlMnSi)) are isomorphous and form uninterrupted solid solutions with each other. The compound of higher electron: atom ratio in the system aluminium-iron-silicon (β(AlFeSi)) has no counterpart in the aluminium-cobalt-silicon system, but Co 2 Al 9 dissolves silicon until the electron: atom ratio is raised sufficiently to overlap the range of electron: atom ratios characteristic of β(AlFeSi). As the number of vacancies for electrons per atom of transitional metal decreases, the ternary compounds formed tend to move to progressively higher ranges of electron: atom ratio. These results are discussed in relation to previous work, and support the general hypothesis of acceptance of electrons by transitional metals. Of particular significance are the observations that silicon and nickel both dissolve in Co 2 Al 9 until the same maximum electron: atom ratio is reached; that α(AlMnSi) and α(AlFeSi) form uninterrupted solid solutions and, according to the hypothesis, have similar electron:atom ratios; and that structural relationships exist between various compounds whose electron: atom ratios are similar.

scholarly journals The intermetallic compound phases of the system aluminium-manganese-zinc

1947 ◽  
Vol 190 (1020) ◽  
pp. 82-101 ◽  
Keyword(s):  
Ternary Eutectic ◽  
Alloy Formation ◽  
Atom Ratio ◽  
X Ray ◽  
Transitional Metals ◽  
Ternary Compounds ◽  
Manganese Zinc ◽  
Metal Atoms ◽  
Transitional Metal ◽  
Ray Methods

The system aluminium-manganese-zinc has been examined in the range 0 to 95 % of zinc, and 0 to 3 % of manganese. Attention was directed only to the constitution of the alloys above the solidus. Using micrographic and X-ray methods, and the chemical analysis of crystals separated from slowly cooled alloys, it has been shown that, according to composition, the phases MnAl 6 , T 1 , MnAl 4 , T 2 , T 3 and MnAl 3 may crystallize as primary constituents. Both MnAl 6 and MnAl 4 dissolve small quantities of zinc; the phases T 1 , T 2 and T 3 are ternary compounds. The phase T 1 is characterized by a ratio of four aluminium atoms to one of combined solutes, and an electron: atom ratio of 1.85, calculated on the basis of the Pauling theory of transitional metals. According to this theory, transitional metal atoms have vacancies for electrons in their atomi orbitals, and the present experiments in conjunction with earlier work suggest that these may be filled up as a consequence of alloy formation. The phases T 2 and T 3 may be represented respectively by the formulae Mn 2 ZnAl 9 and (Mn.Zn 5 Al 11 . MnAl 3 , which can dissolve small quantities of zinc, enters into equilibrium at a ternary eutectic (Zn 95 %, Mn 0.05 %; 378° C) with the primary solid solutions in zinc and aluminium respectively.

The effective valencies of transition metals in solid solution in gold and silver alloys

1962 ◽  
Vol 267 (1330) ◽  
pp. 313-328 ◽  
Keyword(s):  
Solid Solution ◽  
Transition Metal ◽  
Transition Metals ◽  
Manganese Content ◽  
Axial Ratio ◽  
Ternary Alloys ◽  
Exact Nature ◽  
Atom Ratio ◽  
Electron Atom ◽  
Manganese Alloys

In ternary alloys based on the solution of a third metal in binary close-packed hexagonal 3/2 electron compounds (ζ-phases) it is observed that the axial ratio of the structure is essentially constant at a constant value of the valency electron concentration. From determinations of the lattice spacings of solid solutions of manganese, iron and nickel in the gold-tin ζ-phase, and of manganese in the silver-tin ζ-phase, the effective contributions of electrons to the conduction band of the alloys by the transition metal have been deduced. The maximum effective contributions made by iron and nickel are respectively 1 and 0·8 electron per atom; in both cases the effective valency decreases both with increase in electron: atom ratio and with increase in transition metal content. The maximum effective contribution of manganese is two electrons per atom in gold-tin-manganese alloys, and approximately 1·8 in silver-tin-manganese alloys. Again the values decrease with increasing electron: atom ratio and increasing manganese content. The results are discussed in terms of the existence of virtual bound 3 d states associated with the transition metal. Considered together with previous results obtained on solutions of transition metals in the copper-germanium ζ-phase, they demonstrate the dependence of the effective valencies of transition metals in solid solution in noble metal alloys on the exact nature of the environment of the dissolved atoms.

scholarly journals The constitution of the aluminium-rich aluminium-cobalt-iron alloys, with reference to the role of transitional elements in alloy formation

1948 ◽  
Vol 194 (1038) ◽  
pp. 362-374 ◽  
Keyword(s):  
Equilibrium Diagram ◽  
Alloy Formation ◽  
Similar Amount ◽  
Transitional Metals ◽  
Cobalt Nickel ◽  
Iron Nickel ◽  
Primary Separation ◽  
Solution Proceeds ◽  
Iron Cobalt Alloys

The behaviour of transitional metals in aluminium-rich alloys is of theoretical interest. From a knowledge of the system aluminium-iron-nickel (Raynor & Pfeil 1946-7 a ) it has proved possible to predict the general form of the equilibrium diagram for the aluminium-rich aluminium-cobalt-nickel alloys (Raynor & Pfeil 1946-7 b ). Similar predictions may be made for the aluminium-iron-cobalt alloys. The present paper describes the results of an examination of these alloys undertaken to test the predictions. Using micrographic and X-ray methods, isothermal sections have been established at 640, 600 and 550°C. Only the two intermetallic phases Co 2 Al 9 and FeAl 3 have been recognized. Vertical sections across the aluminium-rich corner of the ternary model have been established by thermal analysis, and the fields of primary separation have been determined. Analysis of extracted primary crystals has shown that Co 2 Al 9 dissolves appreciable amounts of iron, while FeAl 3 dissolves a similar amount of cobalt. In each case the solution proceeds by atomic replacement. The results are discussed in their relation to the theoretical considerations involved, and it is shown that close analogies exist between the alloys of aluminium with iron and nickel, with iron and cobalt, and with cobalt and nickel.

The quaternary system aluminium-iron-cobalt-nickel, with reference to the role of transitional metals in alloys

1950 ◽  
Vol 202 (1070) ◽  
pp. 420-438 ◽  
Keyword(s):  
Quaternary System ◽  
Equilibrium Diagram ◽  
Iron Cobalt ◽  
Atom Ratio ◽  
Transitional Metals ◽  
Electron Atom ◽  
Cobalt Nickel ◽  
Metal Atoms ◽  
Iron Nickel ◽  
Electron Compounds

In a previous publication, the results of an investigation of the aluminium-rich portion of the aluminium-iron-nickel equilibrium diagram were reported and interpreted theoretically (Raynor & Pfeil 1946-7 a ). On the basis of this theoretical work, the forms of the previously unknown equilibrium diagrams for the systems aluminium-iron-cobalt and aluminium-cobalt-nickel were deduced, and subsequently verified quantitatively by experiment (Raynor & Pfeil 1946-76; Raynor & Waldron 1948). In the present paper, similar reasoning has been applied to the quaternary aluminium-iron-cobalt-nickel system, and the form of diagram expected compared with experiment. Previous work has suggested that Co 2 Al 9 and the isomorphous FeNiAl 9 are analogous to electron compounds. If the theory be accepted that transitional metal atoms may absorb electrons in aluminium-rich alloys to an extent governed by the vacancies in their atomic orbitals (or 3 d shells), the two compounds have closely similar electron: atom ratios, and both dissolve nickel to the same limiting electron: atom ratio. Co 2 Al 9 will dissolve more iron than FeNiAl 9 ; the reason for this has been discussed. In the quaternary system, it would be expected that a continuous series of solid solutions, of composition (Fe.Co.Ni) 2 Al 9 , would exist between the two compounds, and that the aluminium-rich boundary of the quaternary body in the tetrahedral equilibrium model would be a plane corresponding to a constant proportion of 2 solute atoms to 9 aluminium atoms. It would also be expected that the whole boundary corresponding to saturation of the quaternary body with nickel would occur at a constant electron-atom ratio. These considerations imply that no other phases, apart from FeAl 3 and NiAl 3 (which dissolve relatively small amounts of the other transitional solutes), enter into equilibrium with the aluminium-rich solid solution, and that the liquidus surfaces for FeNiAl 9 and Co 2 Al 9 merge continuously into each other without a break. Further predictions with regard to the form of the equilibrium diagram may also be made, and these are discussed in the paper. The results of the investigation, which are discussed, confirm previous suggestions that the inter-metallic compounds formed by aluminium and transitional metals may, if sufficient aluminium is present, be regarded as analogous to electron compounds, with absorption of electrons by the transitional metal atoms occurring. The theory may be used, in favourable cases, to predict quantitatively the forms of uninvestigated complex equilibrium diagrams. In the present case, equilibrium relationships in a quaternary system have been predicted from those in the three subsidiary ternary systems, two of which were themselves largely predicted as a result of the original theoretical in terpretation of the aluminium-iron-nickel alloys.

Effect of Bi and In on Microstructure Formation in Sn-3Ag-3Bi-3In/Cu and /Ni Solder Joints

2016 ◽  
Vol 700 ◽  
pp. 142-151 ◽  
Author(s):  
Sergey A. Belyakov ◽  
Christopher M. Gourlay
Keyword(s):  
Solid Solution ◽  
Phase Equilibria ◽  
Ternary Compound ◽  
Fine Particles ◽  
Solder Joints ◽  
Primary Phase ◽  
Significant Fraction ◽  
Microstructure Formation ◽  
Five Phases

Sn-3Ag-3Bi-3In solder has been investigated to improve the understanding of microstructure formation in this solder during solidification and soldering to Cu and Ni substrates. The as-solidified microstructures of Sn-3Ag-3Bi-3In samples were found to consist of a significant fraction of βSn dendrites with a complex eutectic between the dendrites. In total five phases were observed to form during solidification: βSn, Ag3Sn, Bi, ζAg and a “Sn-In-Bi” ternary compound. Soldering of Sn-3Ag-3Bi-3In to substrates changed the phase equilibria in the system and caused the formation of additional phases: Cu6Sn5 during soldering to Cu and Ni3Sn4 and metastable NiSn4 during soldering to Ni. It is shown that metastable NiSn4 forms as a primary phase in a complex 5-component Sn-3Ag-3Bi-3In-Ni system. In and Bi were detected in solid solution in the βSn matrix in amounts of ~1.5-2at% and ~1.2at% respectively. Bi also existed as fine particles of two distinct types. (i): sub-micron (<500nm) coral-like particles and (ii) facetted particles measuring up to 7-8 μm.

scholarly journals Strength, Hardness, and Ductility Evidence of Solid Solution Strengthening and Limited Hydrogen Embrittlement in the Alloy System Palladium-Copper (Cu wt. % 5–25)

Hydrogen ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 262-272
Author(s):  
Sebastian DiMauro ◽  
Gabrielle Legall ◽  
Coleman Lubinsky ◽  
Monica Nadeau ◽  
Renee Tait ◽  
...  
Keyword(s):  
Solid Solution ◽  
Hydrogen Embrittlement ◽  
Copper Content ◽  
Vickers Microhardness ◽  
Copper Alloys ◽  
Alloy System ◽  
Weight Percent ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Palladium Copper Alloys

Strength, hardness, and ductility characteristics were determined for a series of palladium-copper alloys that compositionally vary from 5 to 25 weight percent copper. Alloy specimens subjected to vacuum annealing showed clear evidence of solid solution strengthening. These specimens showed, as a function of increasing copper content, increased yield strength, ultimate strength, and Vickers microhardness, while their ductility was little affected by compositional differences. Annealed alloy specimens subsequently subjected to exposure to hydrogen at 323 K and PH2 = 1 atm showed evidence of hydrogen embrittlement up to a composition of ~15 wt. % Cu. The magnitude of the hydrogen embrittlement decreased with increasing copper content in the alloy.

Ethanol conversion over Ga2O3-ZrO2 solid solution: empirical evidences of the reaction pathway, the surface acid–base property, and role of isolated gallium ion

2021 ◽  
Author(s):  
Takashi Yamamoto ◽  
Akihito Kurimoto ◽  
Riona Sato ◽  
Shoki Katada ◽  
Hirotaka Mine ◽  
...  
Keyword(s):  
Solid Solution ◽  
Reaction Pathway ◽  
Ethanol Conversion ◽  
Acid Base ◽  
Base Property ◽  
Temperature Range ◽  
Acid Base Property

Ethanol conversion by Ga2O3-ZrO2 solid solution was examined in the temperature range 573–773 K, and acetone/isobutene formation was confirmed under cofeeding of H2O vapor. The reaction pathway was empirically investigated...

A Simple Dissolved Metals Mixing Route to Prepare Nanostructured Mg0.8Zn0.2TiO3 Solid Solution

2015 ◽  
Vol 1112 ◽  
pp. 47-52 ◽  
Author(s):  
Frida Ulfah Ermawati ◽  
Suasmoro Suasmoro ◽  
Suminar Pratapa
Keyword(s):  
Solid Solution ◽  
Particle Size ◽  
Rietveld Analysis ◽  
Dissolved Metals ◽  
Intermediate Phases ◽  
Particle Size Analyzer ◽  
Ft Ir ◽  
Xrd Patterns ◽  
Zn Ions

A study of liquid mixing route to synthesize high purity Mg0.8Zn0.2TiO3 nanopowder, a candidate dielectric ceramics, has been successfully performed. Formation of the phases on the dried powder was studied using TG/DTA, XRD and FT-IR data. Rietveld analysis on the collected XRD patterns confirmed the formation of solid solution in the system. Such solid solution can be obtained from the powder calcined at 500 °C, but calcination at 550 °C gave rise to the most optimum molar purity up to 98.5% without intermediate phases. The role of Zn ions on the formation of solid solution was also discussed. Homogeneity of particle size distribution and nano-crystallinity of the system was verified from the particle size analyzer data, TEM image and the Rietveld analysis output.

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