Evolution on phase composition and properties of alumina-based ceramics fabricated from high-titania special-grade natural bauxite micropowder

Riqing Du, Lvping Fu, Huazhi Gu, Siu Wing Or, Ao Huang, Renxiang Lv, Qiong Luo

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

In this study, Al2O3-based ceramics were fabricated with natural bauxite powder as the raw material. The phase compositions evolution behavior during the heat treatment and its influence on the properties of fabricated ceramics were investigated. With increasing heat treatment temperature, the sintering degree of high-titania special-grade bauxite became better. The samples showed decreased porosity, increased bulk density, Vickers hardness, fracture toughness and flexural strength. However, when the heat temperature increased to 1650 °C, decomposition of tieillite occurs in sample, leading to increased Al2O3 and TiO2 content in the liquid phase. Corundum and mullite grains with anisotropic growth appeared in the samples, leading to a decrease in the density, the Vickers hardness and flexural strength of samples decreased consequently. However, those anisotropic grains could prolong the crack propagation path and improve the fracture toughness of the material.

Original languageEnglish
JournalCeramics International
DOIs
Publication statusAccepted/In press - 2021

Keywords

  • AlO-Based ceramics
  • Natural bauxite
  • Phase compositions
  • Properties

ASJC Scopus subject areas

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

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