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Processing and Microstructure of Mullite‐Zirconia Composites Prepared from Sol‐Gel Powders
Author(s) -
YUAN QIMING,
TAN JIAQI,
SHEN JIYAO,
ZHU XUANHUI,
YANG ZHENGFANG
Publication year - 1986
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.1151-2916.1986.tb07423.x
Subject(s) - mullite , materials science , sintering , cubic zirconia , microstructure , tetragonal crystal system , stoichiometry , sol gel , ceramic , grinding , composite material , mineralogy , chemical engineering , phase (matter) , chemistry , nanotechnology , organic chemistry , engineering
A high‐purity stoichiometric mullite precursor was obtained by hydrolysis of the alkoxides Al(OC 3 H 7 ) 3 and Si(OC 2 H 2 ) 4 . Fully sintered mullite ceramics can be prepared from sol‐gel powders by sintering them at 1600°C for 4 h in air with the addition of 15 to 20 Vol% ZrO 2 or 1 to 3 mol% Y 2 O 3 or both. Introduction of 1 to 3 mol% Y 2 O 3 aids the retention of tetragonal ZrO 2 ; the volume fraction of t ‐ZrO 2 retained increases with increasing Y 2 O 3 content. The maximum t ‐ZrO 2 retained reaches 34% in a matrix of synthetic mullite with 3 mol% Y 2 O 3 , but most of this t ‐ZrO 2 does not undergo stress‐induced transformation during grinding.