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Light Metal Systems. Part 2: Selected Systems from Al-Cu-Fe to Al-Fe-Ti PDF

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Preview Light Metal Systems. Part 2: Selected Systems from Al-Cu-Fe to Al-Fe-Ti

Intro d u c t i o n XI Introduction Data Covered The seriesfocuses on light metal ternary systems and includes phase equilibria of importance for alloy development, processing or application, reporting on selected ternary systems of importance to industrial light alloy development and systems which gained otherwise scientific interest in the recent years. General The series provides consistent phase diagram descriptions for individual ternary systems. The representation of the equilibria of ternary systems as a function of temperature results in spacial diagrams whose sections and projections are generally published in the literature. Phase equilibria are described in terms of liquidus, solidus and solvus projections, isothermal and pseudobinary sections; data on invariant equilibria are generally given in the form of tables. The world literature is thoroughly and systematically searched back to the year 1900. Then, the published data are critically evaluated by experts in materials science and reviewed. Conflicting information is commented upon and errors and inconsistencies removed wherever possible. It considers those, and only those data, which are firmly established, comments on questionable findings and justifies re-interpretations made by the authors of the evaluation reports. In general, the approach used to discuss the phase relationships is to consider changes in state and phase reactions which occur with decreasing temperature. This has influenced the terminology employed and is reflected in the tables and the reaction schemes presented. The system reports present concise descriptions and hence do not repeat in the text facts which can clearly be read from the diagrams. For most purposes the use of the compendium is expected to be self- sufficient. However, a detailed bibliography of all cited references is given to enable original sources of information to be studied if required. Structure of a System Report The constitutional description of an alloy system consists of text and a table/diagram section which are separated by the bibliography referring to the original literature (see Fig. 1). The tables and diagrams carry the essential constitutional information and are commented on in the text if necessary. Where published data allow, the following sections are provided in each report: Literature Data The opening text reviews briefly the status of knowledge published on the system and outlines the experimental methods that have been applied. Furthermore, attention may be drawn to questions which are still open or to cases where conclusions from the evaluation work modified the published phase diagram. Binary Systems Where binary systems are accepted from standard compilations reference is made to these compilations. In other cases the accepted binary phase diagrams are reproduced for the convenience of the reader. The selection of the binary systems used as a basis for the evaluation of the ternary system was at the discretion of the assessor. Landolt-Börnstein MSIT® New Series IV/11A2 XII Introduction Heading Literature Data Binary Systems Solid Phases Pseudobinary Systems Invariant Equilibria Text Liquidus, Solidus, Solvus Surfaces Isothermal Sections Temperature-Composition Sections Thermodynamics Materials Properties and Applications Miscellaneous References Miscellaneous Materials Properties and Applications Thermodynamics Temperature-Composition Sections Tables and Isothermal Sections diagrams Liquidus, Solidus, Solvus Surfaces Invariant Equilibria Pseudobinary Systems Solid Phases Binary Systems Fig. 1: Structure of a system report Solid Phases The tabular listing of solid phases incorporates knowledge of the phases which is necessary or helpful for understanding the text and diagrams. Throughout a system report a unique phase name and abbreviation is allocated to each phase. Phases with the same formulae but different space lattices (e.g. allotropic transformation) are distinguished by: – small letters (h), high temperature modification (h > h ) 2 1 (r), room temperature modification (1), low temperature modification (l > l ) 1 2 – Greek letters, e.g., (cid:74),(cid:74)' – Roman numerals, e.g., (I) and (II) for different pressure modifications. In the table “Solid Phases” ternary phases are denoted by * and different phases are separated by horizontal lines. MSIT® Landolt-Börnstein New Series IV/11A2 Intr o d u c t i o n XIII Pseudobinary Systems Pseudobinary sections describe equilibria and can be read in the same way as binary diagrams. The notation used in pseudobinary systems is the same as that of vertical sections, which are reported under “Temperature-Composition Sections”. Invariant Equilibria The invariant equilibria of a system are listed in the table “Invariant Equilibria” and, where possible, are described by a constitutional “Reaction Scheme” (Fig. 2). The sequential numbering of invariant equilibria increases with decreasing temperature, one numbering for all binaries together and one for the ternary system. Equilibria notations are used to indicate the reactions by which phases will be – decomposed (e- and E-type reactions) – formed (p- and P-type reactions) – transformed (U-type reactions) For transition reactions the letter U (Übergangsreaktion) is used in order to reserve the letter T to denote temperature. The letters d and D indicate degenerate equilibria which do not allow a distinction according to the above classes. Liquidus, Solidus, Solvus Surfaces The phase equilibria are commonly shown in triangular coordinates which allow a reading of the concentration of the constituents in at.%. In some cases mass% scaling is used for better data readability (see Figs. 3 and 4). In the polythermal projection of the liquidus surface, monovariant liquidus grooves separate phase regions of primary crystallization and, where available, isothermal lines contour the liquidus surface (see Fig. 3). Isothermal Sections Phase equilibria at constant temperatures are plotted in the form of isothermal sections (see Fig. 4). Temperature – Composition Sections Non-pseudobinary T-x sections (or vertical sections, isopleths, polythermal sections) show the phase fields where generally the tie lines are not in the same plane as the section. The notation employed for the latter (see Fig. 5) is the same as that used for binary and pseudobinary phase diagrams. Thermodynamics Experimental ternary data are reported in some system reports and reference to thermodynamic modelling is made. Notes on Materials Properties and Applications Noteworthy physical and chemical materials properties and application areas are briefly reported if they were given in the original constitutional and phase diagram literature. Miscellaneous In this section noteworthy features are reported which are not described in preceding paragraphs. These include graphical data not covered by the general report format, such as lattice spacing – composition data, p-T-x diagrams, etc. Landolt-Börnstein MSIT® New Series IV/11A2 XIV Introduction e bl a reactiontemperatureof 261°C monovariantequilibrium stdown to lowtemperatures secondternaryeutecticreaction Bi) g e5+ ( Bi-A 1 Ag) 26 ((cid:156) l m u m ctic reactionternary maxiature) Ag-Tl-Bi 294e(max)2L (Ag) + TlBi(cid:156)3 L + TlBi (Ag) + (Tl)(h)289U(cid:156)31 (Ag) + (Tl)(h) + TlBi289e(min)34L (Ag) + (Tl)(h)(cid:156) 207e(max)6L (Ag) + TlBi(cid:156)23 L (Ag)+(Bi)+TlBi197E(cid:156)231 Bi(Ag)+(Bi)+Tl23 L (Ag)+TlBi+TlBi188E(cid:156)3232 (Ag)+TlBi+TlBi323 (Tl)(h) TlBi + (Tl)(r),(Ag)144D(cid:156)31 (Ag)+(Tl)(r)+TlBi3 equation of eutectoidreaction at 144°C uteper first binary e(highest tem Tl-Bi 303e1 (Tl)(h)+TlBi(cid:156)3 202e7 (Bi)+TlBi(cid:156)23 192e8 TlBi+TlBi(cid:156)323 44e9h) TlBi+(Tl)(r)(cid:156)3 cheme l l l 1 Tl)( on s ( cti ond binaryectic reaction Ag-Tl 291e3l (Ag)+(Tl)(h)(cid:156) 234d1(Tl)(h) (Tl)(r),(Ag)(cid:156) Figure 2: Typical rea ecut se MSIT® Landolt-Börnstein New Series IV/11A2 Intro d u c t i o n XV C Data / Grid: at.% Axes: at.% δ p 1 700 20 80 500°C isotherm, temperature is usualy in °C primaryγ-crystallization γ 500 40 400°C 60 liquidus groove to decreasing temperatures binary invariant 40 0 reaction 300 estimated 400°C isotherm e 2 U e ternary invariant 60 140 reaction 00 β(h) 3 80 400 α 300 E 400 500 700 20 limit of known region A 20 40 60 80 B Fig. 3: Hypothetical liquidus surface showing notation employed C Data / Grid: mass% Axes: mass% phase field notation estimated phase boundary γ 20 80 γ+β(h) 40 60 phase boundary three phase field (partially estimated) experimental points L+γ (occasionally reported) 60 40 tie line L+γ+β(h) 80 L β(h) 20 L+β(h) L+α limit of known region α Al 20 40 60 80 B Fig. 4: Hypothetical isothermal section showing notation employed Landolt-Börnstein MSIT® New Series IV/11A2 XVI Introduction 750 L phase field notation C 500 ° e, ur at er p m Te L+α 32.5% L+β(h) concentration of abscissa element 250 L+α+β(h) β(h) temperature, °C β(h) - high temperature 188 modification α β(r) - room temperature modification α+β(h) β(r) alloy composition in at.% 0 A 80.00 60 40 20 A 0.00 B 0.00 B 80.00 C 20.00 Al, at.% C 20.00 Fig. 5: Hypothetical vertical section showing notation employed References The publications which form the bases of the assessments are listed in the following manner: [1974Hay] Hayashi, M., Azakami, T., Kamed, M., “Effects of Third Elements on the Activity of Lead in Liquid Copper Base Alloys” (in Japanese), Nippon Kogyo Kaishi, 90, 51-56 (1974) (Experimental, Thermodyn., 16) This paper, for example, whose title is given in English, is actually written in Japanese. It was published in 1974 on pages 51- 56, volume 90 of Nippon Kogyo Kaishi, the Journal of the Mining and Metallurgical Institute of Japan. It reports on experimental work that leads to thermodynamic data and it refers to 16 cross- references. Additional conventions used in citing are: # to indicate the source of accepted phase diagrams * to indicate key papers that significantly contributed to the understanding of the system. Standard reference works given in the list “General References” are cited using their abbreviations and are not included in the reference list of each individual system. MSIT® Landolt-Börnstein New Series IV/11A2 Int r o d u c t i o n XVII General References [C.A.] Chemical Abstarts - pathways to published research in the world's journal and patent literature - http://www.cas.org/ [Curr.Cont.] Current Contents - bibliographic multidisciplinary current awareness Web resource - http://www.isinet.com/products/cap/ccc/ [E] Elliott, R.P., Constitution of Binary Alloys, First Supplement, McGraw-Hill, New York (1965) [G] Gmelin Handbook of Inorganic Chemistry, 8th ed., Springer-Verlag, Berlin [H] Hansen, M. and Anderko, K., Constitution of Binary Alloys, McGraw-Hill, New York (1958) [L-B] Landolt-Boernstein, Numerical Data and Functional Relationships in Science and Technology (New Series). Group 3 (Crystal and Solid State Physics), Vol. 6, Eckerlin, P., Kandler, H. and Stegherr, A., Structure Data of Elements and Intermetallic Phases (1971); Vol. 7, Pies, W. and Weiss, A., Crystal Structure of Inorganic Compounds, Part c, Key Elements: N, P, As, Sb, Bi, C (1979); Group 4: Macroscopic and Technical Properties of Matter, Vol. 5, Predel, B., Phase Equilibria, Crystallographic and Thermodynamic Data of Binary Alloys, Subvol. a: Ac-Au ... Au-Zr (1991); Springer-Verlag, Berlin. [Mas] Massalski, T.B. (Ed.), Binary Alloy Phase Diagrams, ASM, Metals Park, Ohio (1986) [Mas2] Massalski, T.B. (Ed.), Binary Alloy Phase Diagrams, 2nd edition, ASM International, Metals Park, Ohio (1990) [P] Pearson, W.B., A Handbook of Lattice Spacings and Structures of Metals and Alloys, Pergamon Press, New York, Vol. 1 (1958), Vol. 2 (1967) [S] Shunk, F.A., Constitution of Binary Alloys, Second Supplement, McGraw-Hill, New York (1969) [V-C] Villars, P. and Calvert, L.D., Pearson's Handbook of Crystallographic Data for Intermetallic Phases, ASM, Metals Park, Ohio (1985) [V-C2] Villars, P. and Calvert, L.D., Pearson's Handbook of Crystallographic Data for Intermetallic Phases, 2nd edition, ASM, Metals Park, Ohio (1991) Landolt-Börnstein MSIT® New Series IV/11A2 Al–Cu–Fe 1 Aluminium – Copper – Iron Cui Ping Wang, Xing Jun Liu, Liming Zhang, Kiyohito Ishida Literature Data Critical evaluation of constitutional data in the Al-Cu-Fe system has been done by [1991Leg] covering the then known literature. The present evaluation updates and amends this work within the same evaluation program. The investigations on the phase equilibria in the Al-rich portion have been carried out by [1924Fue, 1925Got, 1928Arc, 1928Gwy, 1932Yam, 1933Rol, 1934Fue, 1939Bra2, 1939Nis, 1940Fin, 1940Hun, 1940Shi, 1940Wie, 1941Bro, 1948Sha, 1950Phr, 1952Han, 1954Phi, 1984Ben, 1992Gay1, 1992Gay2, 1992Zak, 1993Fau1, 1993Fau2, 2000Yok1, 2000Yok2, 2000Yok3, 2001Ros], and two reviews have been presented by [1961Phi] and [1976Mon]. The Cu-rich equilibria have been studied by [1938Nis, 1939Bra1, 1941Yut] and [1952Haw] and the Fe-rich equilibria by [1939Bra1]. The effect of small amount of Fe on the phase equilibria in the Al-Cu alloys was reported by [2001Liu], and that of Cu on site occupancy and diffusion behavior in the Al-Fe alloys was studied by [1997And, 2002Ban] and [1998Akd], respectively. [1997Oht] determined the liquid/solid equilibria in the Cu-Fe side on the basis of thermodynamic calculation and diffusion couple technique, and the extensive investigation of [1997Oht] was continued by [1998Wan], in which solid/solid equilibria and an order-disorder transition of the bcc phase are included. More recently, [2002Zha, 2003Zha1, 2003Zha2, 2003Zha3, 2003Zha4] carried out detailed experimental investigations of the phase equilibria in the Al-rich portion around the icosahedral quasicrystalline phase region on the basis of the techniques of differential thermal analysis, magnetothermal analysis, scanning electron microscopy and X-ray diffraction. [2003Mie] presented a thermodynamic assessment for the phase equilibria in the Cu-Fe side portion. The different fields of crystallization are proposed by [1939Bra2] and [1971Pre], but in [1939Bra2] the phase (cid:45) is missing and in [1971Pre] the compositions given are not in good agreement with their published 1 diagram. General studies about the system have been proposed by [1935Bos, 1936Bra, 1940Bra, 1955Tur, 1956Spe, 1969LeM, 1972Miu, 1972Pro, 1973Kow, 1975Wac, 1978Pan1, 1981Bre] and [1987Str]. In particular, in the past decade, enormous investigations on crystal structure and physical and mechanical properties of icosahedral quasicrystalline phase have been performed by [1991Aud1, 1991Aud2, 1991Bes, 1991Che1, 1991Che2, 1991Fau, 1991Jan, 1991Men, 1991Lei, 1991Liu1, 1991Liu2, 1991Qui, 1991Wu, 1991Zha, 1992Che1, 1992Che2, 1992Eib, 1992Mat, 1992Nas, 1993Ban, 1993Bes, 1993Lee, 1993Men, 1993Was, 1994Bes, 1994Fre1, 1994Fre2, 1994Law, 1994Lef, 1995Div, 1996Qui, 1997Div, 1997Ham, 1997Pop, 1997Ros, 1997She, 1998Dun, 1998Ma, 2000Bou, 2000Dun, 2000Gre1, 2000Gre2, 2000Jon, 2000Nak, 2000Sha, 2000Ste, 2000Uch, 2001Bar, 2001Cai, 2001Gui, 2001Jon, 2001Sur, 2001Guo, 2002Hir, 2002Gre, 2002Kra, 2002Sha]. Binary Systems The Al-Cu binary system was reviewed by [1985Mur], and has been adopted from [1994Mur] with modification of [1998Liu], where it is found that earlier reported phase (cid:7) does not exist, and the earlier 0 reported two-phase equilibrium ((cid:11) +(cid:11) ) was determined as second order reaction (cid:11) -(cid:11) in the composition 0 1 1 0 range of 62-68 at.% Cu. The Al-Fe and Cu-Fe binary systems have been accepted from [1993Kat] and [2001Tur], respectively. Solid Phases Data on all solid phases are given in Table 1. The existence of a stable single icosahedral quasicrystalline phase ((cid:45)) has been reported for the first time by [1987Tsa1] and [1987Tsa2] and later on by a series of i research groups [1988Bou, 1988Hir, 1988Ish, 1988Tsa, 1989Dev, 1989Don, 1989Eba]. The formation range of the icosahedral phase found by [1987Tsa1] is close to the composition range of a ternary phase discovered by [1939Bra2] and referred to as (cid:53) phase (about 20 to 26 at.% Cu and 12 to 13 at.% Fe) the Landolt-Börnstein MSIT® New Series IV/11A2 2 Al–Cu–Fe structure of which was left unidentified. [1990Cal] has demonstrated that the (cid:53) phase is indeed the icosahedral phase. Following [1990Fau1, 1991Fau], the composition range of the icosahedral phase is around Fe Cu Al . [1939Bra2, 1989Don, 1990Fau1, 2000Yok1, 2000Yok2] and [2003Zha1] agree 12.5 25.5 62 that the icosahedral (cid:45) phase formation proceeds following a peritectic reaction. i There is also a general agreement that the Al-Cu-Fe icosahedral phase corresponds to an F type structure which can be seen as an ordered F superstructure of the primitive six dimensional (6D) hypercubic lattice [1988Ish, 1989Dev, 1989Eba] and exists as a single phase stable at 800°C. At lower temperatures (about 600°C) the structure strongly depends on the composition of the alloy. For compositions around Fe Cu Al the icosahedral phase is perfect, without phasons and without any modification even after 12.5 25.5 62 annealing for 4 days at 500°C. For compositions different but close to this domain, either a modulated structure appears [1991Aud1] or even a transformation towards periodic phases (rhombohedral) [1990Den]. Further investigations of crystall structure with an emphasis of phase transition and thermal stability of Al-Cu-Fe quasicrystalline in bulk and layer states have been carried out by many groups on the basis of experiment and theory [1991Aud1, 1991Aud2, 1991Bes, 1991Che, 1991Dub, 1991Eib, 1991Fau, 1991Jan, 1991Lei, 1991Liu1, 1991Liu2, 1991Men, 1991Wu, 1991Zha, 1992Che1, 1992Che2, 1992Eib, 1992Hay, 1992Lu, 1992Mat, 1992Nas, 1993Ban, 1993Lee, 1993Men, 1993Nas, 1993Was, 1994Bes, 1994Fre1, 1994Fre2, 1994Law, 1994Lef, 1995Div, 1996Log, 1996Qui, 1997Div, 1997Ham, 1997Pop, 1997Ros, 1997She, 1998Dun, 1998Ma, 1999Rot, 2000Bou, 2000Dun, 2000Gre1, 2000Gre2, 2000Jon, 2000Nak, 2000Sha, 2000Ste, 2000Uch, 2001Cai, 2001Gui, 2001Guo, 2001Qia, 2002Gre, 2002Kra, 2002Sha]. Large grains with an average size of 0.2 mm were obtained by [1987Tsa2] and [1990Cal]. Further replacement of Cu by Al in (Fe Cu Al )alloys was said to reveal a three-phase structure of (Al)+ 15 20-x 65+x FeAl +FeCu Al [1988Tsa]. 3 2 7 Pseudobinary Systems and Temperature – Composition Sections The section Al Fe-Al Cu was reported by [1928Arc] as a pseudobinary system, however, this section is not 3 2 exactly pseudobinary [1928Arc, 1990Fau2]. Some pseudobinary phase diagrams along the composition lines of the Cu Al - Fe Cu Al , Fe Cu Al - Fe Cu Al , Fe Cu Al - Fe Cu Al and 35 65 20 15 65 1.5 30 68.5 1.5 40 58.5 3 30 67 3 40 57 Fe Cu Al - Fe Cu Al were determined by [2000Yok1, 2000Yok2], which show that the primary 5 30 65 5 40 55 crystal from the melt is the (cid:27) phase, and then (cid:45) phase is formed by a peritectic reaction. [2000Yok1 and i 2000Yok2] only focused on the two-phase (L+(cid:45)) region, and did not give detailed information. In addition, i it was found that some phase equilibria do not follow the phase equilibria rules. More recently, [2003Zha2] reported a series of vertical phase diagrams, including the pseudobinary systems along the Fe Al -Cu Al (Fig. 1), Cu Al - Fe Cu Al (Fig. 2), Cu Al - Fe Cu Al 22.8 77.2 57.5 42.5 10 90 20 30 50 37.5 62.5 20 21 59 (Fig. 3), Fe Al - Fe Cu Al (Fig. 4) and the vertical section diagrams with 25 at.% Cu, 5 at.% 14.5 85.5 3.5 50 46.5 Fe, 7.5 at.% Fe, 10 at.% Fe, and 12 at.% Fe (Figs. 5-9). In the investigations of [2002Zha, 2003Zha2], the phase equilibria of the (cid:45) phase and other related phases are precisely described, and the icosahedral phase i is formed via a peritectic reaction (L+(cid:27)+(cid:7)(cid:156)(cid:45)) at 882°C, the shrinkage of the phase field with decreasing i temperature gives an indication of the compositional influence on the stability of the icosahedral phase. [1939Bra1, 1939Bra2, 1971Pre] reported the existence of slightly distorted structures of the (cid:27) phase. In Fig.1 [2003Zha2] shows them as two phases, labeled as (cid:27) and (cid:27) , based on of the results of [1939Bra1, 1 2 1939Bra2 and 1971Pre]. However, none of the authors [1939Bra1, 1939Bra2, 1971Pre, 2003Zha1, 2003Zha2, 2003Zha3] studied these structures in details. [2003Zha2] did not distinguish between (cid:19) and (cid:19) except for the vertical section shown in Fig. 3, where 1 2 these two phases are distinguished. This is mainly concluded from their existence in the binary Al-Cu system and supported by a few DTA and MTA measurements. According to this section a ternary reaction corresponding to the (cid:19) and (cid:19) transition occurs at a temperature between ~595 and 565°C, involving liquid 1 2 phase. Below this temperature only (cid:19) should exist. However, [2003Zha1, 2003Zha2, 2003Zha3] did not 2 consider this fact in the reaction scheme and in other vertical sections and used (cid:19) as notation in all figures. Further investigations would be required to clarify phase equilibria involving different modifications of the (cid:27) phase, as well as the (cid:19) and (cid:19) phases. 1 2 MSIT® Landolt-Börnstein New Series IV/11A2 Al–Cu–Fe 3 It should be noted that the vertical sections presented here from [2003Zha2] are not always coherent with the accepted binary systems. [1998Wan] presented the calculated vertical section diagrams of 5, 10, and 15 mass% Al with a consideration of the ordered structure of the bcc phase ((cid:5)(cid:13)Fe), as shown in Figs. 10-12, which indicate that the B2 ordered phase ((cid:7)) is not formed in the 5 mass% Al vertical sections. However, the metastable and stable A2/B2 ordering reaction (((cid:5)(cid:13)Fe)/(cid:7)) appears in the 10 and 15 mass% Al vertical sections, respectively; and the miscibility gap of the B2 phase ((cid:7)) also appears in 15 mass% Al vertical section. Invariant Equilibria Two partial reaction schemes in the Cu-rich and Al-rich corners were proposed by [1938Nis] (Fig. 13), and [1954Phi, 2003Zha3], respectively. In the Al-rich corner [2003Zha3] presented a detailed Scheil reaction scheme including solid state reactions, where 13 four-phase equilibria, three three-phase eutectic equilibria, four three-phase peritectic equilibria, and two three-phase eutectoid reactions are included (Fig. 14). In the Cu-rich portion the invariant reactions related to the (cid:7) phase are revised, as shown in Fig. 13, because 0 [1998Liu] reported that no (cid:7) phase exists at high temperature in the Al-Cu system. The reaction at 1048°C, 0 given as L+T(cid:156)((cid:11)Fe)+Cu Al by [1938Nis], where the phase T was considered to be a ternary compound, is 3 not compatible as a transition type reaction with the other equilibria, but should be a peritectic type L+((cid:5)(cid:13)Fe)+((cid:11)Fe)(cid:156)Cu Al. 3 The invariant reactions are listed in Table 2. Liquidus Surface Polythermal projections of the liquidus surface are proposed in Figs. 15 and 16 for the Cu- and Al- rich corners, respectively. Figure 17 shows combined projection of liquidus surface with tie lines of the four-phase equilibria based on the works of [1991Leg] and [2003Zha1]. The ternary phase (cid:45) , close to (cid:45), 4 i is omitted in these figures. A partial liquidus surface diagram in the Al-rich portion and the formation temperature of (cid:45) phase is presented by [2000Yok1, 2000Yok2], which is in basic agreement with that i reported by [2003Zha1], who constructed the liquidus surface in the Al-rich portion, as shown in Fig. 16, where 12 four-phase equilibria with the liquid phase exist. Isothermal Sections Figure 18 shows the Al-rich part of the isothermal section at room temperature obtained by [1991Fau] by combining experimental results of [1990Cal] with previous literature data in the range of compositions around the icosahedral (cid:45) phase, in which (cid:45) is not shown. Furthermore, [1992Gay1 and [1992Gay2] i 4 determined the isothermal phase diagrams at temperatures from 550-800°C in the Al-rich region using scanning electron microscopy and energy dispersive spectroscopy. This study indicates that the B2 ordered phase ((cid:7)) has considerably greater solubility of Cu than previously reported, extending from AlFe to the composition of about Fe Cu Al . A schematic section at 680°C in the vicinity of the icosahedral region 5 45 50 was determined by [1993Gra] with a combination of the results of [1992Gay1, 1939Bra1]. The results of [1993Gra] show that at 680°C, three crystalline phases surround the icosahedral region: the monoclinic (cid:27) phase, the ordered simple cubic ((cid:7)) phase and ordered tetragonal (cid:45) phase. [2001Ros] constructed the 2 isothermal section at 850°C. [1997Oht] has studied the solid/liquid equilibria in the Cu-Fe portion using diffusion couple method. [1998Wan] performed the experimental determination and thermodynamic calculation of the phase equilibria in the Cu-Fe side portion with a special attention for A2/B2 ordering transition. There exists an order-disorder A2/B2 transition in this system, and a stable B2 phase ((cid:7)) is formed over a wide range of compositions from the Al-Fe binary system to the Al-Cu binary system at 800-1000°C (Figs. 19-24). It is interesting to note that a miscibility gap of the bcc phase ((cid:7)) was divided into A2+A2 (((cid:5)(cid:13)Fe)+Cu Al), A2+B2 (Cu Al+(cid:7)) and B2+B2 (((cid:7)(1)+ ((cid:7)(2)) two-phase regions. [2003Zha3] 3 3 determined isothermal sections at 800, 700, 645, 620, 617, 600, 592 and 560°C using SEM/EDS methods together with structural investigations, as shown in Figs. 25-32, in which the (cid:45) icosahedral quasicrystalline i Landolt-Börnstein MSIT® New Series IV/11A2

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