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Pressureless Sintering of Si 3 N 4 Ceramic Using AlN and Rare‐Earth Oxides
Author(s) -
Huang ZhenKun,
Rosenflanz Anatoly,
Chen IWei
Publication year - 1997
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.1151-2916.1997.tb02972.x
Subject(s) - materials science , pressureless sintering , ceramic , sintering , toughness , phase (matter) , grain boundary , fracture toughness , composite material , solid solution , rare earth , flexural strength , metallurgy , mineralogy , microstructure , chemistry , organic chemistry
Using intermediate, liquid‐forming compositions in the (Y,La) 2 O 3 ‐AlN system as additives, fully dense Si 3 N 4 ceramics with high strength at high temperature have been obtained by pressureless sintering. The ceramics contain rod‐shaped β‐Si 3 N 4 with M′ or K′ solid solutions as grain‐boundary phases. The strength of these ceramics is 1150 MPa at 1200°C, and the room‐temperature toughness is maintained at }7 MPa·m 1/2 . Phase relations that are pertinent to the new additive compositions are delineated to rationalize their beneficial effects on sinterability and mechanical properties.