Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

IRON-GADOLINIUM PHASE DIAGRAM

Technical Report ·
OSTI ID:4806809

Data from the investigation of the iron-gadolinium phase diagram revealed a single eutectic system with very limited terminal solubility and three intermediate phases. The eutectic point occurs at about 85 percent gadolinium, and the eutectic isotherm, which occurs at 850 deg C, extends from the compound Fe/sub 2/Gd to 99-plus percent gadolinium. Very little solubility of the solid phases in each other was observed. The three intermediate phases, Fesub 9/Gd, Fe/ sub 3/Gd, and Fe/sub 2/Gd, melt incongruently at peritectic isotherms at 1320, 1l50, and 1080 deg C, respectively. The crystalline systems of the three phases were determined as follows: Fe/sub 9/Gd, hexagonal; Fe/sub 3/Gd, hexagonal or rhombohedral; and Fe/sub 2/Gd, face-centered cubic. No lowering or raising of the alphagamma iron transformation at 9l0 deg C, the gamma-delta iron transformation at 1388 deg C, or the gadolinium transformation at l262 deg C was observed. The principal methods used in determining the iron--gadolinium phase diagram were melting-point determinations, thermal analyses, metallographic examination, and x-ray diffraction analyses. Melting, heat treating, and thermal analyses were conducted in a vacuum or under a helium atmosphere because of the avidity with which oxygen combines with gadolinium at elevated temperatures. A few hardness values were determined, but they had no part in the derivation of the phase diagram. No other mechanical properties were determined. (auth)

Research Organization:
Bureau of Mines. Albany Metallurgy Research Center, Ore.
NSA Number:
NSA-16-012086
OSTI ID:
4806809
Report Number(s):
BM-RI-5925
Country of Publication:
Country unknown/Code not available
Language:
English