OPTIMIZATION OF MECHANICAL AND ELECTRICAL -PROPERTIES OF TIN SI3N4 MATERIAL BY AGGLOMERATES-MICROSTRUCTURE-CONTROL (PART 2) - AGGLOMERATE SIZE EFFECT/

Agglomerates of Si3N4 and TiN were co-sintered to fabricate a TiN/Si3N 4 ceramic displayed a duplex microstructure. The agglomerate s-microst ructure-controlled material (A) showed electrical conductivity at a lo wer TIN content (9.8 vol%) than the theoretical value of a material wi th a nonuniform microstructure. This is because the ratio of R-TiN (ra dius of TiN agglomerates) to R-SN (radius of Si3N4 agglomerates) was 8 , causing TiN agglomerates to be arranged around large Si3N4 agglomera tes. It is concluded that the lower critical volume % for conductivity of this material resulted from the formation of a network of TiN sphe rical agglomerates with a smaller amount of additive.