Premium
A New SiC‐Whisker‐Reinforced Lithium Aluminosilicate Composite
Author(s) -
Xue Liang A.,
Chen IWei
Publication year - 1993
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.1151-2916.1993.tb04016.x
Subject(s) - materials science , mullite , composite material , flexural strength , aluminosilicate , composite number , sintering , whisker , creep , superplasticity , fracture toughness , ceramic , whiskers , ceramic matrix composite , microstructure , biochemistry , chemistry , catalysis
The glass‐ceramic matrix of the well‐known lithium aluminosilicate (LAS)/SiC composite is usually formulated near the spodumene composition. We report here a new composition which is rich in alumina (78 wt%) and lean in silica (21 wt%) and lithia (1 wt%). This formulation offers a new option of converting the glass‐ceramic matrix to a mullite/alumina matrix upon annealing above 1400°C, and hence better creep resistance and other high‐temperature mechanical properties. Using a transient‐phase processing method that we developed previously for the superplastic forming of mullite, we are able to hot‐press a composite containing 30 vol% SiC whiskers at ∼1350°C to achieve full density. Flexural strength measurements up to 1400°C have confirmed the improved high‐temperature strength and creep resistance over conventional LAS. The fracture toughness is also higher than that of LAS. The results suggest that the new composition may be chosen as a better candidate matrix for SiC‐fiber‐reinforced composites.