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Sintering and Microstructure Formation of β‐Silicon Carbide
Author(s) -
STUTZ DORIS H.,
PROCHAZKA SVANTE,
LORENZ JOSEF
Publication year - 1985
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.1151-2916.1985.tb15812.x
Subject(s) - sintering , microstructure , materials science , redistribution (election) , annealing (glass) , silicon carbide , pressureless sintering , metallurgy , grain growth , carbide , politics , political science , law
The effect of additions of B, Al, and B + Al on the pressureless sintering of β‐Sic was examined. The influence of the sintering atmosphere and heating schedule on densification behavior, polytype transformation, and microstructure development was also studied. High densities were obtained at 1940°C by the simultaneous addition of B and Al. The decrease in the sintering temperature is attributed to the presence of a liquid phase which results in the formation of platelets (up to 200 # in size) of an α‐polytype, predominantly 4H and 6H. Polytype transformation and exaggerated grain growth could be prevented by annealing the compact at 1650° to 18500°C for 0.5 to 1 h. This procedure results in a better redistribution of the sintering aids, giving a fine‐grained microstructure, constituted primarily of the cubic 3C polytype.