Open AccessReactions of uranium and the platinide elements. III. The uranium-iridium system
Author(s) -
John J. Park,
Lyle R. Mullen
Publication year - 1968
Publication title -
journal of research of the national bureau of standards. section a. physics and chemistry
Language(s) - English
Resource type - Journals
eISSN - 2376-5704
pISSN - 0022-4332
DOI - 10.6028/jres.072a.003
Subject(s) - iridium , uranium , allotropy , eutectic system , intermetallic , melting point , materials science , phase diagram , crystallography , chemistry , metallurgy , phase (matter) , alloy , biochemistry , organic chemistry , composite material , catalysis
The phase diagram of the uranium-iridium system was constructed from data obtained by thermal analysis, metallographic examination, and x-ray diffraction. The system is characterized by five intermetallic compounds: U 3 Ir, formed peritectically near 945 °C and decomposing eutectoidally near 758 °C; U 3 Ir 2 , formed peritectically near 1121 °C; UIr, melting congruently at about 1470 °C; UIr 2 , formed peritectically above 1850 °C; and UIr 3 , having a congruent melting point above 1950 °C. U 3 Ir 2 has a solid state transition near 898 °C. One eutectic occurs at 914 °C at about 15 atom percent (a/o) iridium between uranium and U 3 Ir; a second occurs between UIr and UIr 2 near 1450 °C; and a third occurs between UIr 3 and iridium at about 1950 °C The solid solubility of iridium in gamma-uranium is about 5.5 a/o and of uranium in iridium is under 3 a/o. Iridium lowers the gamma-beta uranium transformation to about 681 °C and the beta-alpha transformation to about 565 °C.