Effect of Sintering Temperature and Yttrium Composition on the Densification, Microstructure and Mechanical Properties of Spark Plasma Sintered Silicon Nitride Ceramics with Al2O3 and Y2O3 Additives

Ntombikazi Jojo, Mxolisi Brendon Shongwe, Lerato Criscelda Tshabalala, Peter Apata Olubambi

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

Three types of silicon nitride ceramics powder blends were sintered by spark plasma sintering at different temperatures and pressures. The relative densities, microstructures, hardness and toughness of the material were investigated with the sintering behaviour. It was observed that the relative density depends on the sintering temperature, the sintering pressure and the yttrium composition. The densification of the sintered ceramics increased with increasing sintering temperature, application of step pressure and yttrium composition, facilitating necking of grains. This in turn affected the microstructure and the mechanical properties of the materials in a manner that the highly dense material induced full compacted particle deformation observed in the microstructures and also high mechanical properties of as high as 1841 HV and 8,87 MPa·√m with the relative density of 99%.

Original languageEnglish
Pages (from-to)2689-2699
Number of pages11
JournalSilicon
Volume11
Issue number6
DOIs
Publication statusPublished - 1 Dec 2019

Keywords

  • Densification
  • Hardness
  • Microstructure
  • Spark plasma sintering
  • Toughness

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

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