Effect of α/β phase ratio on microstructure and mechanical properties of silicon nitride ceramics

Hirokazu Kawaoka, Tomohiko Adachi, Tohru Sekino, Yong Ho Choa, Lian Gao, Koichi Niihara

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Highly densed silicon nitride ceramics with various α/β phase ratios were produced by pulse electric current sintering process. The β-phase content of Si3N4 in sintered materials varied from 20 to 100 wt% depending on the sintering condition. The microstructure was observed by scanning electron microscopy and investigated by image analysis. Young's modulus, hardness, fracture toughness, and strength were strongly dependent on the α/β phase ratio. The fracture toughness increased from 4.6 MPa m1/2 for 20-wt% β-phase content to 8.2 MPa m1/2 for 95-wt% β-phase content, and the fracture strength showed a maximum value of about 1.6 GPa at 60-to-80-wt% β-phase content.

Original languageEnglish
Pages (from-to)2264-2270
Number of pages7
JournalJournal of Materials Research
Volume16
Issue number8
DOIs
Publication statusPublished - 2001 Aug 1

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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