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Inverse Segregation of MgO and MgAI 2 O 4 in Fusion‐Cast Bodies
Author(s) -
RIBBE P. H.,
ALPER A. M.
Publication year - 1964
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1964.tb14384.x
Subject(s) - spinel , eutectic system , materials science , periclase , metallurgy , solidus , casting , inverse , fusion , thermodynamics , composite material , microstructure , alloy , linguistics , geometry , philosophy , physics , mathematics
Rapidly cooled castings formed from certain liquids in the system Mg0‐MgA1204 are observed to have an enrichment of the low‐melting spinel in the early solidified skin of the casting. Periclase, the high‐melting phase, is concentrated in the core of the casting. Following the metallurgical literature, an explanation for this nonequilibrium phenomenon, known as inverse segregation , is advanced which involves volume contraction upon solidification and flow‐back of residual, spinel‐rich liquids along interdendritic channels to the contraction volumes. The dependence of phase segregation on cooling history is discussed. Inverse segregation is negligible near the eutectic and extreme near the 70 wt% MgO concentration.