A least three eutectics, one peritectic, and one ternary compound (11 cao.7 Al2o3.Caf2) characterize the metallurgically important system caf2-cao-al2o3 under one-third atmosphere helium. Primary phases of common fluxes used in the electroslag remelting process include caf2, 11 cao.7 Al2o3.Caf2 (probably in solid solution with 12 cao.7 Al2o3) cao, and cao.Al2o3. Nearly all of these fluxes crystallize to the three eutectics whose compositions (weight- percent) and temperatures were determined as (1) 43 caf2-40 cao-17 al2o3, 1,193 deg +/-5 deg. C; (2) 51 caf2-19 cao-30 al2o3, 1,352 deg +/-7 deg c; and (3) 69 caf2-6 cao-25 also3, 1,377 deg. +/-4 Deg. C. Small postulated phase fields of 3 cao.Al2o3 and cao.Al2o3 are due to reactions with caf2. A two-liquid region and a stable compound (3 cao.3 Al2o3.Caf2) were not detected, in contrast to sealed capsule experiments described in the literature. The system in air would probably show slight modifications from the present results owing to phase hydrolysis.
High Temperature Sci., V. 5, No. 6, December 1973, PP. 414-422