Author/Authors :
D. Buc?evac، نويسنده , , S. Bos?kovic´، نويسنده , , B. Matovic´، نويسنده , , Lj. Z? ivkovic´، نويسنده , ,
M. Vlajic´، نويسنده , , Vladimir Krstic، نويسنده ,
Abstract :
Microstructure development and fracture toughness
of Si3N4 composites were studied in the presence of seeds
and Al2O3 + Y2O3 as sintering aids. The elongated b-Si3N4
seeds were introduced into two different a-Si3N4 matrix
powders; one was the ultra fine powder matrix and the other
was the coarse powder matrix. The amount of seeds varied
from 0 to 6 wt%. The grain growth inhibition and the mechanism
of toughening were discussed and correlated with
microstructure. The maximum fracture toughness of
9.0 MPa m1/2 was obtained for ultra fine powder with 5 wt%
seeds hot pressed at 1,700 C for 6 h.
