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Cu-C and Al-Cu-C phase diagrams and thermodynamic properties of c in the alloys from 1550 deg. C to 2300 deg. C.

Authors
Oden-LL; Gokcen-NA
Source
Metall Trans B 1992 Aug; 23(4):453-458
NIOSHTIC No.
10011361
Abstract
The Cu-C and Al-Cu-C phase diagrams were determined at 1550 C to 2300 C by chemical and X-ray diffraction analyses of alloys saturated with carbon within sealed graphite crucibles. Isothermal sections for the ternary system were determined at intervals of 150 C over the range of temperatures investigated. The univariant points in atomic percent on the 1700 C, 1850 C, and 2000 C isotherms are 70.7Al-28.9Cu-0.4C, 74.4Al-24.0Cu-1.6C, and 78.3Al-17.0Cu-4.7C, respectively, as determined by metallographic examination of rapidly cooled alloys. Graphite and Al4C3 (decomposition temperature 2156 C) were the only solid phases observed at these temperatures. The excess partial Gibbs energy for dissolved carbon in the liquid Al-Cu-C solutions in equilibrium with C, as calculated from the experimental solubilities, is G c e = - RT lnx =y 2[176,860 - 55.42T - (224,200 - 110.84T)x] +z 2[237,000 - 48.61T] +yz[320,510 - 36.77T + (30,180 + 35.10T)z + (51,570 - 74.13T)yz + (246,400 - 88.04T)yz 2 - 60,000], J/g atom where R is the gas constant,T is the temperature in K, andx, y, andz are the atomic fractions of C, Al, and Cu, respectively. The equation also is a good approximation for liquid solutions in equilibrium with A14C3.
Keywords
Metal-compounds; Metallic-compounds; Metallic-minerals; Metallurgical-processes; Temperature-effects; Aluminum-compounds
CODEN
MTTBCR
CAS No.
7782-42-5; 7429-90-5
Publication Date
19920801
Document Type
OP; Journal Article
Fiscal Year
1992
NTIS Accession No.
NTIS Price
Identifying No.
OP 189-92
Issue of Publication
4
ISSN
0360-2141
NIOSH Division
ALRC
Source Name
Metallurgical Transactions. B. Process Metallurgy
State
OR
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