Premium
Phase stability (at 1000°C) of hollow t‐ZrO 2 fibers costabilized by lanthana and yttria
Author(s) -
Pang Xu,
Xi Chang,
Wang Tianchi
Publication year - 2020
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13490
Subject(s) - materials science , yttria stabilized zirconia , yttrium , composite material , cubic zirconia , thermal stability , tetragonal crystal system , scanning electron microscope , phase (matter) , monoclinic crystal system , thermal conductivity , fiber , lanthanum , chemical engineering , ceramic , crystal structure , metallurgy , crystallography , inorganic chemistry , chemistry , organic chemistry , engineering , oxide
Yttrium‐stabilized ZrO 2 (YSZ) hollow fibers derived from a ceiba template present a 25%–53% reduction in thermal conductivity compared with traditional YSZ solid fibers. However, after prolonged preservation at 1000°C, tetragonal ZrO 2 (t‐ZrO 2 ) can easily transform to monoclinic ZrO 2 (m‐ZrO 2 ), which destroys the hollow structure of the YSZ fibers and results in loss of the structural advantages for heat insulation. To overcome this, in this study, biomorphic lanthana and yttrium costabilized zirconia (LaYSZ) fibers with a hollow structure are fabricated by doping appropriate amounts of lanthanum in the raw materials of YSZ fibers. X‐ray diffraction, scanning electron microscopy, and thermal conductivity measurements are utilized to confirm the phase‐stability superiority of LaYSZ fibers to that of YSZ fibers under harsh conditions. After preservation at 1000°C for 150 hours, the m‐ZrO 2 content in the LaYSZ hollow fibers increases from 0 to 3.4 mol%, whereas that in the YSZ fibers increases from 0 to 10.25 mol%. Furthermore, owing to their better phase stability at 1000°C, the morphologies and heat‐insulating properties of LaYSZ fibers are more improved in several aspects compared with YSZ fibers.