A successful sol-gel process to encapsulate molybdenum di-silicide MoSi2 particles with a closed and thermally stable Al2O3 layer using aluminium tri-sec-butoxide as a precursor is presented. The processing conditions such as precursor selection and temperature were optimized through analysing the interaction of the MoSi2 particles with the sol. The application of the sol-gel based coating was followed by calcining the coated particles at temperatures between 900 and 1200 °C in Ar. The shell composition and the mechanical stability of the microcapsule were analysed by means of X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. Upon calcining at 1200 °C in Ar, the MoSi2 core remains intact as it is, covered by an α - alumina shell with a thickness of about 0.6 μm. The stability tests proved that the encapsulate particles are about five times more oxidation resistant than the uncoated MoSi2 particles.

Original languageEnglish
Pages (from-to)2728-2734
JournalJournal of the European Ceramic Society
Volume38
Issue number7
DOIs
Publication statusPublished - 2018

    Research areas

  • Alumina shell, MoSi, Self-healing thermal barrier coatings, Sol-gel

ID: 42510493