General ReferencesThe following list of references has provided the foundation for much of the phase diagram data that is currentlycited in the literature. To conserve space in the present publication, these references are cited by their general referencesymbol in text.[Beryllium]: P.J. Spencer, O. von Goldbeck, R. Ferro, KDiagrams, Business Growth Services, General ElectricCo., Schenectady, NY (1976).Girgis, and A.L.Dragoo, Beryllium:Physico-Chemical[Molybdenum]:L.Brewer,Molybdenum:Physico-Chem-Properties of Its Compounds and Alloys, O.Kubas-ical Properties of Its Compounds and Alloys, O. Kubas-chewski, Ed., Atomic Energy Review Special Issue No.4,InternationalAtomicEnergyAgency,Vienna (1973).chewski, Ed., Atomic Energy Review Special Issue No.[Brandes]: E.A. Brandes and R.F. Flint, Ed., Manganese7, International Atomic Energy Agency,Vienna (1980).Phase Diagrams, The Manganese Centre, 17 Avenue[Niobium]: V.I. Lavrentev, Ya.I. Gerassimov, P. Fes-Hoche, 75008 Paris, France (1980).chotte, D.T. Livey, O. von Goldbeck, H. Nowotny, K.[Chiotti]: P.Chiotti, V.V.Akhachinskij, and I. Ansara,Seifert, R. Ferro, and A.L. Dragoo, Niobium: Physico-The Chemical Thermodynamics of Actinide ElementsChemical Properties of Its Compounds and Alloys, O.and Compounds, Part 5: The Actinide Binary Alloys,Kubaschewski, Ed., Atomic Energy Review Special Is-V. Medvedev, M.H. Rand, E.F. Westrum, Jr., and F.Lsue No. 2, International Atomic Energy Agency, Vi-Oetting, Ed., International Atomic Energy Agency, Vi-enna (1968)[Pearsonl]: W.B. Pearson, Handbook of Lattice Spacingsenna (1981).[Elliott]:R.P.Elliott, Constitution of Binary Alloys,Firstand Structures of Metals and Alloys, Vol. 1, PergamonSupplement, McGraw-Hill, New York, or General Elec-Press, New York (1958).[Pearson2]:W.B. Pearson,Handbook of Lattice Spacingstric Co., Business Growth Services,Schenectady,NY(1965).and Structures of Metals and Alloys, Vol. 2, Pergamon[Gschneidner]: K.A. Gschneidner, Jr. and F.W. Calder-Press, New York (1967).[Plutoniuml: M.H. Rand, D.T. Livey, P.Feschotte, H.wood, in Handbook of the Physics and Chemistry of RareEarths, Vol. 8, K.A. Gschneidner, Jr. and L. Eyring, Ed.,Nowotny, K. Seifert, and R.Ferro, Plutonium: Physico-North-HollandPhysicsPublishing,Amsterdam (1986).Chemical Properties of Its Compounds and Alloys, O.[Hafnium]: P.J. Spencer, O. von Goldbeck, R. Ferro, R.Kubaschewski, Ed., Atomic Energy Review Special Is-Marazza, K. Girgis, and O. Kubaschewski, Hafnium:sue No. I, International Atomic Energy Agency, Vi-Physico-Chemical Properties of Its Compounds and Al-enna (1966).[Princel: A. Prince, Alloy Phase Equilibria, Elsevier, Newloys, K.L.Komarek, Ed., Atomic Energy Review Spe-York (1966).cial ssue No. 8, International Atomic Energy Agency,Vienna (1981).[Shunk]: F.A. Shunk, Constitution of Binary Alloys, Sec-[Hansenl: M. Hansen and K. Anderko, Constitution ofond Supplement, McGraw-Hill, New York, or GeneralBinary Alloys, McGraw-Hill, New York, or GeneralElectric Co., Business Growth Services, Schenectady,Electric Co., Business Growth Services, Schenectady,NY (1969).NY(1958)[Smith]: J.F. Smith, O.N. Carlson, D.T. Peterson, and T.E.[Hultgren, B): R. Hultgren, P.D. Desai, D.T. Hawkins,Scott, Thorium:Preparation and Properties, Iowa StateM. Gleiser, and K.K. Kelley, Selected Values of theUniversity Press, Ames, IA (1975).Thermodynamic Properties of Binary Alloys, American[Smithells]: C.J. Smithells and E.A. Brandes, Metals Ref-Society for Metals, Metals Park, OH (1973)erence Book, 5th ed., Butterworths, Woburn, MA (1976).[Hultgren, E]: R. Hultgren, P.D. Desai, D.T. Hawkins,[Spear]:K.E.Spear,"Correlations and Predictions ofM. Gleiser, K.K. Kelley, and D.D. Wagman, SelectedMetal-Boron Phase Equilibria,Applications of PhaseValues of the Thermodynamic Properties of the Ele-Diagrams in Metallurgy and Ceramics, Vol. 2, NationalBureau of Standards Special Publication No. 496, Na-ments, American Society for Metals, Metals Park, OH(1973)tional Bureau of Standards, Gaithersburg, MD 20899,[Ivanov]: O.S. Ivanov, T.A. Badaeva, R.M. Sofronova, V.B.(1978); "Phase Behavior and Related Properties of Rare-Kishenevskii, and N.P.Kushnir, Phase Diagrams ofEarth Borides," Refractory Materials, Vol. 6-IV, A.M.Uranium Alloys, Nauka, Moscow (1972).Alper, Ed., Academic Press, New York (1976).[Kingl]: H.W. King, "Crystal Structures of the Elements[Tantalum]: Ya.I. Gerassimov, V.I. Lavrentev, O. vonat 25 °C," Bull. Alloy Phase Diagrams, 2(3), 401-402Goldbeck, D.T. Livey, R. Ferro, and A.L. Dragoo, Tan-(1981)talum:Physico-Chemical Properties of Its Compounds[King2]: H.W.King,"Temperature-Dependent Allotropicand Alloys, O. Kubaschewski, Ed., Atomic Energy Re-Structures of the Elements, Bull. Alloy Phase Dia-view Special Issue No. 3, International Atomic Energygrams,3(2),275-276;3(3),308 (1982).Agency,Vienna (1972).[Thorium]: M.H. Rand, O. von Goldbeck, R. Ferro, K.[King3]: H.W. King, "Pressure-Dependent AllotropicStructures of the Elements," Bull. Alloy Phase Dia-Girgis, and A.L. Dragoo, Thorium: Physico-Chemicalgrams,4(4),449-450(1983)Properties of Its Compounds and Alloys, O. Kubas-[Kubaschewski]: O. Kubaschewski, Iron-Binary Phasechewski, Ed., Atomic Energy Review Special Issue No.Diagrams, Springer-Verlag, New York (1982)5,International AtomicEnergyAgency,Vienna (1975)[Melti: "Melting Points of the Elements," Bull. Alloy Phase[Zirconium]: C.B. Alcock, K.T. Jacob, S. Zador, O. vonDiagrams,2(1),145-146(1981).Goldbeck, H. Nowotny, K. Seifert, and O. Kubas-[Metals]:Metals Handbook, Metallography,Structures andchewski,Zirconium: Physico-Chemical Properties of ItsPhase Diagrams, Vol. 8, 8th ed., American Society forCompounds and Alloys, O.Kubaschewski, Ed.,AtomicMetals, Metals Park, OH (1973).Energy Review Special Issue No. 6, International Atomic[Moffatt]: W.G. Moffatt, Ed., Handbook of Binary PhaseEnergy Agency, Vienna (1976).xit
ciated with very limited primary solid solubility. In these instances, it was most often assumed that a definite tem-perature difference had been measured. Therefore, the invariant temperature and the melting point were both adjustedby the same amount.In some original sources, crystal structure information for the intermetallic phases in a given system is presentedalong with the diagram selected for inclusion in these volumes. In such instances, this information is therefore includedwith the edited diagram. In most cases, however, it was necessary to search out the crystal structure data from otherstandard sources.Production of DiagramsAll of the phase diagram graphics for this book were produced using a computer software program for digitizing datafrom mixed numerical and graphical input, interactive labeling and annotation, and generation of camera-ready output.The graphics program allows generation of diagrams in atomic or weight percent composition scales from one set ofdata, with user-selected composition and temperature ranges. Software was also used to verify that appropriate phaseboundaries meet correctly at invariant lines and congruent points. This technique of data entry, editing, and checking.as well as the exercise of producing both atomic and weight percent diagrams,brought to light some interesting problemsthat would not have appeared if the diagrams had been produced by draftsmen in one composition scale only, but thatare in fact intrinsic to the treatment of phase diagram data. However, the use of interactive computer graphics hasallowed our data-entry staff to revise and revise again until a clear, reasonable, and self-consistent diagram was ob-tained, regardless of the composition scale used.Style of PresentationSeveral aspects of presentation were standardized for all Program and non-Program diagrams. Terminal solid solu-tions are uniformlydesignated by the name of theallotrope of theelement in parentheses, such as (Cr)or (αTi).Completesolid solutions are designated by the names of both elements, such as (βTi, βY) or (Cu, Pd).A stoichiometric phase name is used in preference to arbitrary lettering (for example, A,B, rather than ). Greekletter prefixes are used to indicate high-and low-temperature forms (for example, βA,B,).However, many exceptionshad to bemade.Category Editors'preferencesfor Greek letter nomenclatures,or in terms of special labeling-Ali,Mn(LT), for example, to designate a low-temperature form-have been taken into account. Some systems have traditionalphase names that are permanently established. Greek letters conventionally are used for certain phases, particularlydisordered solutions: β for disordered bcc, or e for disordered cph, for the y-brass-type structure, and for the uCrFe-type structure, for example.Only single-phase fields are labeled. Where a range of homogeneity exists, either the label is placed within the field,or an arrow ends within the single-phase field. Line compounds are labeled vertically.Exceptions were made for limitedsolubility in any phase. In these instances, labeling of the two-phase fields is both visualiy more pleasing and allowsunambiguous identification of the invariant lines. Other exceptions are miscibility gaps that do not close within thediagram.Composition and temperature labels generally are included only for invariant lines and congruent points. Space con-siderations dictated some exceptions, and confusion of labels and arrows was avoided first by omitting units and thenbyomittinglabelson oneof thetwo diagrampresentations.Dashed lines are used for uncertain or speculative boundaries, whereas dot-dashed lines are used for magnetic orsecond-order transformations (magnetic transformations are also explicitly labeled as such or abbreviated as "Magn.Trans."). It must be emphasized that "uncertain" may take on a different meaning for each evaluator and, for a givenevaluator, may take on a different meaning for each diagram: from"these data are somewhat less accurate than thedata for the rest of the diagram" to "this curve was drawn free-hand to complete the diagram." Although evaluatorsoften have impulses to express their opinion of the state of a diagram by drawing it entirely in dashed, dotted, or evencompletely invisible lines, they generally restrain themselves and use the dashed lines to indicate the least-knownboundaries. In a few diagrams (notably actinides) where there are many uncertain areas consisting of many short linesegments, solid lines had to be used to make the area decipherable.Parallel sets of tick marks are provided for both composition and temperature axes, for ease of extracting data. Insteadof printing grid lines at 10% and 100 'C intervals, ten times the number of ticks are provided, thus improving both thequalitative clarity of the diagrams and their quantitative usefulness. For the most part, intervals of only 50, 100, 200,and 500 C are used on the temperature scale. Diagrams extending to zero K are drawn starting at -300 °C, with ahorizontal line indicating the bottom of the diagram.AcknowledgmentThe phase diagrams for this book were digitized by Elizabeth A. Aellen, Krista L. Ballentine, Leslie K. CharltonPeter S. Darby, Rosetta V.Drew, Linda D.Fong, Chandrashekhar S. Kanetkar, Sang Ju Lee, Todd H. LeeuwenburghTambra A. Leonard, Lynette F. Lilly, Hope E. Rubin, Nancy E. Stott, and Linda B. Wilkinson, each and every one ofwhom displayed skill, patience, and a cooperative spirit above and beyond the call of duty. Anthony Datel and EarlZmiejewski showed the same qualities in their contributions to the computer programming effort.It has been a pleasureworkingwith the entire computer andgraphics staff atNBS.J.L.MurrayEditor,Bulletin of AlloyPhaseDiagramsxii
Ac-Au, Ac-BAc-CrAc-Au (Actinium-Gold)227.0278196.9665H.OkamotoandT.B.Massalski; submitted to theAPDProgramNo phase diagram is available forAc-Au Crystal Structure Datathe Ac-Au system. The melting pointsof Ac and Au are 1051 ± 50 andComposition,PearsonStrukturberichtPhasePrototypeat.%AusymbolSpace groupdesignation1064.43°C,respectively[Melt].Fromthe position of Ac in the periodic ta-0A1CuCF4Fm3mAcble, the solubility of Ac in (Au) at the.100CF4Fm3mAlCuAueutecticreaction involving (Au)wasestimated tobe 10-2to 10-"at.%Ac[68Gul].68Gul: B.B. Gulyaev and G.F. Dvorsh-temsM.Savitskii,d.,Akad.NauComplete evaluation containsI table andkaya, Phase Diagrams of Metallic Sys-Moscow,267-273(1968)inRussian.3references.Ac-B (Actinium-Boron)227.027810.81[Spearl constructed a hypotheticalAc-B phase diagram by analogy withthe system La-B.Ac-Cr (Actinium-Chromium)227.027851.996L.Venkatraman, J.P.Neumann, and D.E. Peterson; Bull. Alloy Phase Diagrams, 6(5), Oct 1985Although no studies of the Cr-AcCr-Ac Crystal Structure Datasystem have been reported, it is as-Composition,PearsonSpaceStrukturberichtsumedthat Cr and Ac formasimplePhasesymbolPrototypeat.%Acgroupdesignationeutectic phase diagram. Based onstudies of other Cr-actinide systems,wA2c12Im3m(Cr)~0the following features are also as-CF4A1Cu~100Fm3m(Ac)sumed: (1) complete mutual solubil-ity in the liquid state; (2) negligiblemutual solubility in the solid state;and (3) the absence of intermediateThe Cr-actinidesystemsdonot show78Gie: B.C. Giessen and R.O. Elliott, Proc.phases. For the Cr liquidus, the melt-3rd Int. Conf. Rapidly Quenched Met-ing temperature of Cr was taken asthe liquid miscibility gap that is typ-als, The Metals Society,London, 1, 406-1863 C, for the Ac liquidus, theical of most of the Cr-lanthanide411 (1978)melting temperature of Ac was takensystems, probably because of the78Pol:D.E. Polk and B.C. Giessen, Me-difference in the atomic volumesas1051%tallic Glasses, J.J. Gilman and J.H.[King2]The assessed phase diagram for theLeamy,Ed., American Society for Met-Cr-Ac system has been calculated,The Cr-actinide systems areknownals (1978),for their ease of glass formationdespite the lack of thermodynamic83Gie:B.C.Giessen and S.H.Wang,Alloydata, by assuming that the liquid al.[78Gie, 78Poll, which is attributed toPhase Diagrams, L.H. Bennett, T.B.Massalski, and B.C. Giessen, Ed., North-loys form an ideal solution. Accord-the low eutectic temperatures rela-Holland,NewYork,289-294(1983)ing to the calculations, the eutectictiveto themelting points of thepurepoint occurs at approximately 700 °Ccomponents and the small terminalComplete evaluation contains 1 figure, land approximately 70 at.%Ac.solid solubilities [83Gie].table, and 3 references.1Binary AlloyPhaseDiagrams
Ac-CrAssessedCr-AcPhaseDiagramWeight Percent Actiniurm50708090Q1020304060100200019001883℃180017001600150081400L1300120011001051℃1000900800700(Cr)600(Ac)50020305080O1040607090100CrAtomic PercentActiniumAcAtomic Percent Actinium01020304050607080100200019001883℃1800170016001500o01400L1300120011001051℃1000900800700600(Cr)(Ac)5009001020304050607080100CrWeight Percent ActiniumAcCalculated.M.Venkatraman,J.P.Neumann,andD.E.Peterson,1985.2BinaryAlloyPhaseDiagrams