Premium
Processing, Microstructure, and Strength of Alumina–YAG Eutectic Polycrystals
Author(s) -
Mah TaiIl,
Parthasarathy Triplicane A.,
Kerans Ronald J.
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.tb01518.x
Subject(s) - eutectic system , materials science , microstructure , equiaxed crystals , yttrium , crystallite , grain size , metallurgy , composite material , grain boundary , fracture toughness , oxide
Dense polycrystalline eutectics of alumina and yttrium aluminum garnet (YAG) were fabricated by hot‐pressing powders of pulverized arc‐melted buttons at homologous temperatures of 0.9 T eu –0.93 T eu (where T eu is the eutectic temperature). The eutectic microstructure of the arc‐melted buttons was retained after densification, although the grain boundaries were decorated with equiaxed grains of alumina and YAG ∼1–5 μm in size; possible causes for their formation have been discussed. A comparison of the measured strength of the polycrystalline eutectics (274 ± 61 MPa) with grain size and fracture toughness suggests that the strength‐limiting flaws are significantly smaller than the mean grain size and larger than the mean eutectic spacing.