PURPOSE: To obtain a material excellent in wear resistance at high temp. and used for partially reinforcing a piston for an internal-combustion engine, etc., by forming a preform made of a blend of short Al2O3 fibers with TiO2 whiskers, impregnating a molten Al alloy into the preform and carrying out squeeze casting.
CONSTITUTION: A molten Al alloy is impregnated into a preform made of a blend of short Al2O3, fibers with TiO2 whiskers and squeeze casting is carried out to obtain the objective composite material in which a dense hard part contg. a Ti-Al intermetallic compd. accounts for 30-80% (by area) of the fine structure measured with an optical microscope of 100 magnifications. The Ti-Al intermetallic compd. is one or more among Ti2Al, TiAl and TiAl3. The Vickers microhardness Hv of the hard part is 140-250. The volume fraction of the short Al2O3 fibers and that of the TiO2 whiskers in the preform for producing the composite alloy are preferably regulated to 8-15% and 5-12%, respectively.
HIYAMA TAKASHI
ARITA KAZUJI
FUKUNAGA HIDEHARU
JAPAN RES DEV CORP