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In Situ Processing of Silicon Carbide Layer Structures
Author(s) -
Padture Nitin P.,
Pender David C.,
Wuttiphan Sataporn,
Lawn Brian R.
Publication year - 1995
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.1151-2916.1995.tb09104.x
Subject(s) - materials science , microstructure , silicon carbide , layer (electronics) , ceramic , sintering , composite material , bilayer , phase (matter) , equiaxed crystals , silicon , metallurgy , chemistry , genetics , organic chemistry , membrane , biology
A novel route to low‐cost processing of silicon carbide (SiC) layer structures is desribed. The processing involves pressureless liquid‐phase cosintering of compacted power layers of SiC, containing alumina (Al 2 O 3 ) and yttria (Y 2 O 3 sintering additives to yield and yttrium aluminum garnet (YAG) second phase. By adjusting the β:α SiC phase ratios in the individual starting powders, alternate layers with distinctively different microstructures are produced: (i) “homogeneous” microstructures, with fine equiaxed SiC grains, designed for high strength; and (ii) “heterogeneous: microstructures with coarse and elongate SiC grains, designed for high toughness. By virtue of the common SiC and YAG phases, the interlayer interfaces are chemically compatible and strongly bonded. Exploratory Hertzian indetation tests across a bilayer interface confirm the capacity of the tough heterogeneous layer to inhibit potentially dangerous cracks propagating through the homogeneous layer. The potential for application of this novel processing approach to other layer architectures and other ceramic systems is considered.