Premium
Improvement of Mechanical and Electrical Properties of Scandia‐Doped Zirconia Ceramics by Post‐Sintering with Hot Isostatic Pressing
Author(s) -
Hirano Masanori,
Inagaki Michio,
Mizutani Yasunobu,
Nomura Kazuhiro,
Kawai Masayuki,
Nakamura Yasuhisa
Publication year - 2000
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2000.tb01600.x
Subject(s) - materials science , hot isostatic pressing , cubic zirconia , sintering , ceramic , electrical resistivity and conductivity , grain size , doping , tetragonal crystal system , composite material , hot pressing , metallurgy , mineralogy , phase (matter) , chemistry , engineering , organic chemistry , optoelectronics , electrical engineering
Significant improvement in the fracture strength, accompanied by an enhancement in the electrical conductivity, of zirconia polycrystals that were doped with 3–7 mol% Sc 2 O 3 was obtained by sintering at 1300°C for 1 h in air, followed by hot isostatic pressing (HIP) at 196 MPa at 1300° and 1450°C for 1.5 h in an argon‐gas atmosphere. Dense bodies (with an average grain size of <0.5 μm) that were doped with 3.5 mol% of Sc 2 O 3 showed the highest average fracture strength up to 1770 MPa and an electrical conductivity of 0.08 S/cm at 1000°C. The present zirconia ceramics, which consisted of submicrometer‐sized grains of tetragonal phases and were stabilized with 5 and 6 mol% of Sc 2 O 3 , exhibited high strength (1330 and 1140 MPa, respectively) and good conductivity (0.15 and 0.18 S/cm, respectively); values for both properties were greater than those previously reported. The present HIPed zirconia ceramics, which have excellent properties, are candidates for an electrolyte of planar‐type solid oxide fuel cells.