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      https://www.ias.ac.in/article/fulltext/boms/017/02/0095-0103

    • Keywords

       

      Alumina; sol-gel

    • Abstract

       

      The processing of alumina ceramics using the sol-gel technique was investigated. Alumina sols were prepared by precipitation-peptization of aluminium hydroxide obtained from aluminium nitrate and aluminium oxyhydroxide obtained from aluminium isopropoxide. Sols cast on Teflon substrate were gelled by controlled dehydration at near-ambient temperature. Gels were converted to ceramics through processes of drying, calcination and sintering in the temperature range 773–1473 K. Ceramics derived from both the sols retained a porosity of 35–45% even after sintering at 1273 K. However, at 1473 K densification was drastically enhanced and bodies could be sintered to about 90–93% of theoretical density (TD) and was accompanied by theϑ-to-α transformation. The progress of the reactions occurring at various stages of the process was studied using pycnometry, TG-DSC, XRD, SEM, MIP and TEM techniques.

    • Author Affiliations

       

      S Ramanathan1 R Bhat1 D D Upadhyaya1 S K Roy1

      1. Metallurgy Division, Bhabha Atomic Research Centre, Bombay - 400 085, India
    • Dates

       
  • Bulletin of Materials Science | News

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