Effect of TiO₂ and TiB₂ on Pressureless Sintering of B₄C

Abstract:

This paper presents results of experiments on pressureless sintering of boron carbide (B₄C) with addition of titânia (TiO₂) and titanium diboride (TiB₂). The TiB₂ powder was added as a second phase and the TiO₂ powder for reactive sintering and in-situ formation of TiB₂. The final concentrations of TiB₂ in the composites were 0 to 10 vol%. Sintering was performed at 2050 °C/30min in argon atmosphere. TiO₂ was completely transformed into TiB₂ with fine equiaxed grains distributed homogeneously. Composites obtained by in-situ reaction showed a densification increase with the concentration increase, while the composites with TiB₂ powder mixture showed low densification in all compositions. Relative Density of the composite with 10 vol% of TiB₂ obtained in-situ was 91% (TD) compared to 86 % for B₄C only. Vickers hardness was about 29 GPa.

• Periodical: Materials Science Forum (Volumes 727-728)
• Pages: 1022-1027
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.727-728.1022
• Online since: August 2012
• Authors: Rosa Maria da Rocha, Francisco Cristóvão Lourenço de Melo
• Keywords: B₄C, Composite, Covalent Ceramics, Sintering, TiB₂

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