Spray freeze granulation of sub-micrometer α-alumina using ultrasonication

Research output: Contribution to journalArticlepeer-review


  • Shaghayegh Ghanizadeh
  • Prabhu Ramanujam
  • Bala Vaidhyanathan
  • Jon Binner

External organisations

  • Loughborough University


Granulation is a key factor towards improvement of the flowability of fine ceramic powders to make them suitable for industrial dry pressing. Controlled granulation of fine alumina particles with a primary particle size of ~150 nm was carried out using spray freeze drying, which led to the production of flowable granules with high crushability. The fracture surface of uniaxially die-pressed green bodies made from granules with density values of ≥50% of theoretical showed a uniform microstructure. Sintering experiments were performed using conventional single- and two-stage radiant heating methods followed by density and grain size measurement and characterisation of the final dense compacts to study the efficiency of two-stage sintering in grain growth elimination. The results have been compared with those of alumina bodies prepared using similar suspension by slip casting route.


Original languageEnglish
Pages (from-to)455-462
JournalJournal of Ceramic Science and Technology
Issue number4
Publication statusPublished - 22 Nov 2017


  • alumina , granulation , spray freeze drying , two-stage sintering