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Fabrication and microstructure characterization of continuously porous Si2N2O–Si3N4 ceramics

2006; Elsevier BV; Volume: 61; Issue: 11-12 Linguagem: Inglês

10.1016/j.matlet.2006.08.043

1873-4979

Byong‐Taek Lee, Rajat Kanti Paul, Chi‐Woo Lee, Hai-Doo Kim,

Magnesium Oxide Properties and Applications

Abstract The microstructure of continuously porous Si 2 N 2 O–Si 3 N 4 ceramics fabricated for use in environmental filters by a multi-pass extrusion process was investigated using SEM, XRD and TEM techniques. The matrix regions of the nitrided Si 2 N 2 O–Si 3 N 4 porous bodies were composed of many Si 3 N 4 particles and short Si 2 N 2 O fibers. However, in the continuously porous regions, many network type Si 2 N 2 O fibers, 200–420 nm in diameter, with a high aspect ratio were observed. After post-sintering of the nitrided bodies at 1800 °C, the diameter of the fibers increased to about 2–3 μm, while their length was shortened. The values of bending strength, relative density and hardness of the post-sintered Si 2 N 2 O–Si 3 N 4 bodies were about 117.6 MPa, 73.6% and 616 Hv, respectively.