TY - JOUR
T1 - α-SiAION ceramics densified with mixed oxide sintering additives
AU - Mandal, Hasan
AU - Oberacker, R.
PY - 2000
Y1 - 2000
N2 - Densification and stabilization of α-sialon ceramics were investigated by using oxides of large cations (Sr2+, La3+, Ce3+, Nd3+) and their equi-molar mixtures with CaO or Yb2O3. All multi-cation and single cation (only Nd3+ and Ce3+) doped samples could be densified to nearly full density even by pressureless sintering. X-ray diffraction of the samples densified with single cations revealed that the oc-sialon structure could accomodate Nd3+ or Ce3+ cations. In Sr- and La- systems, however, S- (-SrO:I.3Al2O3:0.7Si2N2O) and N- (La3Si8O4N) phases were found to be stable rather than a-sialon. In case of multi-cations, a-sialon was observed only as a matrix phase. EDX measurements proved that Ce-, La- and Sr- cations could be accomodated into the a-sialon structure with the presence of calcium or ytterbium. SEM studies revealed that almost glass free grain boundaries could be obtained by careful design of starting compositions. ©2000 Trans Tech Publications,.
AB - Densification and stabilization of α-sialon ceramics were investigated by using oxides of large cations (Sr2+, La3+, Ce3+, Nd3+) and their equi-molar mixtures with CaO or Yb2O3. All multi-cation and single cation (only Nd3+ and Ce3+) doped samples could be densified to nearly full density even by pressureless sintering. X-ray diffraction of the samples densified with single cations revealed that the oc-sialon structure could accomodate Nd3+ or Ce3+ cations. In Sr- and La- systems, however, S- (-SrO:I.3Al2O3:0.7Si2N2O) and N- (La3Si8O4N) phases were found to be stable rather than a-sialon. In case of multi-cations, a-sialon was observed only as a matrix phase. EDX measurements proved that Ce-, La- and Sr- cations could be accomodated into the a-sialon structure with the presence of calcium or ytterbium. SEM studies revealed that almost glass free grain boundaries could be obtained by careful design of starting compositions. ©2000 Trans Tech Publications,.
KW - Densification
KW - New α-siaions
KW - Phase transformation
KW - Siaion
UR - https://www.mendeley.com/catalogue/8ada868f-d967-3396-b33e-04daf29cb87e/
U2 - 10.4028/www.scientific.net/msf.325-326.207
DO - 10.4028/www.scientific.net/msf.325-326.207
M3 - Article
SN - 0255-5476
VL - 325-326
SP - 207
EP - 212
JO - Materials Science Forum
JF - Materials Science Forum
ER -