Sialon-based ceramic composite materials containing 0-20 wt.% Si3N4 wh
iskers were hot pressed and their mechanical properties and microstruc
tural characterization were investigated. The specimens were subjected
to ball-on-reciprocating plate type wear tests at temperatures betwee
n room temperature and 1073 K. A gas blast type erosion tester was emp
loyed to examine erosion behavior of the composite at room temperature
and 773 K. Si3N4 whiskers caused formation of large elongated grains
in the microstructure. The specimen with the higher content of Si3N4 w
hiskers exhibited higher fracture toughness and lower flexural strengt
h resulting from the larger grain size. Wear test results showed that
a higher wear rate was obtained as whisker content and test temperatur
e increased. Scanning electron microscopy observation on the wear trac
k of specimens containing 0 and 20 wt.% Si3N4 whiskers tested at 1073
K revealed that the one with 20 wt.% of Si3N4 whiskers had deeper groo
ves inside the track than that with 0 wt.% Si3N4 whiskers. Erosion tes
t results showed a tendency similar to that of the wear test results.
The higher the test temperature and the more whiskers the specimen con
tained, the higher the erosion rate. (C) 1997 Elsevier Science S.A.