Effects of milling parameters on the microstructural and thermal properties of nanocrystalline lanthanum hexaboride powders


Ağaoğulları D., Balci O., Öveçoğlu M. L., Duman İ.

JOURNAL OF THE AUSTRALIAN CERAMIC SOCIETY, cilt.54, sa.1, ss.177-190, 2018 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 54 Sayı: 1
  • Basım Tarihi: 2018
  • Doi Numarası: 10.1007/s41779-017-0139-2
  • Dergi Adı: JOURNAL OF THE AUSTRALIAN CERAMIC SOCIETY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.177-190
  • İstanbul Teknik Üniversitesi Adresli: Evet

Özet

This study reports the effects of some milling parameters (duration, ball-to-powder weight ratio (BPR), process control agent (PCA)) on the fabrication of nanocrystalline LaB6 powders via a combined process of mechanochemical synthesis (MCS) and acid leaching, starting from La2O3-B2O3-Mg powder blends. MCS was carried out in a high-energy ball mill (SPEX (TM) 8000D Mixer/Mill, at 1200 rpm) using hardened steel vial and balls under Ar atmosphere. As-synthesized products were leached out with 4 M HCl from unwanted MgO phase and probable Fe impurities. When a BPR of 18:1 was used, 5 h of MCS and leaching yielded LaB6 powders with an average particle size of 100 nm, containing a very small amount of FeB49 phase. Pure LaB6 powders were obtained with an average particle size of 53 nm after 12 h of MCS of the 0.5 wt% PCA added La2O3-B2O3-Mg powder blends with a BPR of 10:1 and after leaching.