skip to main content

Title: Effect of pores on the fracture toughness of TiB{sub 2} / Si3N4 composites

Porosity was significantly increased in proportion to the amount of TiB{sub 2} particles, which were added to silicon nitride ceramics. The existence of TiN, detected by X-ray diffraction analysis and electron probe micro analysis, indicates that these pores were produced by the reaction between TiB{sub 2} particles and silicon nitride ceramics. The crack propagation was deflected at the interface between Si{sub 3}N{sub 4} matrix and TiB{sub 2} particles by the influence of residual stress, which was caused by the difference of thermal expansion coefficients. Also, it is worthy of notice that the crack propagation was restrained by the presence of pores. These phenomena significantly improved the fracture toughness up to 9.5 MPa{circ}m{sup 1/2} for the composite containing 10 vol% TiB{sub 2} particles. Other mechanical properties were also evaluated.
Authors:
; ;  [1]
  1. Noritake Co., Limited, Aichi (Japan)
Publication Date:
OSTI Identifier:
518610
Report Number(s):
CONF-960367--
TRN: 97:003394-0041
Resource Type:
Conference
Resource Relation:
Conference: Workshop on mass and charge transport in ceramics, Nagoya (Japan), 15-16 Mar 1996; Other Information: PBD: 1996; Related Information: Is Part Of Ceramic transactions: Mass and charge transport in ceramics. Volume 71; Koumoto, Kunihito; Sheppard, L.M.; Matsubara, Hideaki [eds.]; PB: 643 p.
Publisher:
American Ceramic Society, Westerville, OH (United States)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; TITANIUM BORIDES; PORE STRUCTURE; FRACTURE PROPERTIES; SILICON NITRIDES; CRACK PROPAGATION; THERMAL EXPANSION; X-RAY DIFFRACTION