Improving the surface hardness of zirconia toughened alumina (ZTA) composites by surface treatment with a boehmite sol

Yuanlong Li, Hyoun Ee Kim, Young-Hag Koh

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13 Citations (Scopus)


This paper reports a novel way of enhancing the hardness of a zirconia-toughened alumina (ZTA) composite with a zirconia content of 20 vol% by surface treatments with a boehmite sol. More specifically, a ZTA composite was first prepared by heat-treating a mixture of alumina and zirconia powders containing Cr 2O 3 and SrAl 11CrO 19, as a reinforcement at 1400 °C for 1 h, and then infiltrating them with the boehmite sol, followed by heat-treatment at 1650 °C for 1 h to densify them. This treatment led to a significant increase in the surface hardness of the ZTA composite, which was attributed mainly to an increase in the volume fraction of an alumina phase with greater hardness, whereas the flexural strength and fracture toughness decreased slightly. The Vickers hardness, flexural strength and fracture toughness were 17.1 ± 2.5 GPa, 738 ± 88 MPa and 4.2 ± 0.11 MPa m 1/2, respectively.

Original languageEnglish
Pages (from-to)2889-2892
Number of pages4
JournalCeramics International
Issue number4
Publication statusPublished - 2012 May 1



  • Alumina
  • C. Mechanical properties
  • E. Biomedical applications
  • Zirconia-toughened alumina

ASJC Scopus subject areas

  • Ceramics and Composites
  • Process Chemistry and Technology
  • Electronic, Optical and Magnetic Materials
  • Surfaces, Coatings and Films
  • Materials Chemistry

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