| 摘要 |
PROBLEM TO BE SOLVED: To ensure superior fracture toughness by firing a composite material obtd. by impregnating polycarbosilane as a matrix material into a three- dimensional fabric of Tyranno(R) fibers as a fibrous material. SOLUTION: A matrix material consisting of polycarbosilane and a coupling agent such as γ-glycidoxypropyltrimethoxysilane is sprinkled on a three- dimensional fabric of Tyranno(R) fibers cut to about 50×25×6mm by about 15-20g per one piece of the fabric and the fabric is put in an autoclave. Heating and evacuation are started and gaseous Ar is introduced in a prescribed vacuum state. At the time when the internal temp. attains to about 300 deg.C, gaseous Ar is introduced to about 100atm and the autoclave is kept at about 300 deg.C for about 1hr and allowed to cool all night. The resultant impregnated fabric is teken out, put in a heating furnace and sintered by heating to about 1,200 deg.C in an atmosphere of gaseous Ar to obtain the objective fiber reinforced ceramic composite material. When gaseous N2 is used at the time of sintering, Si3 N4 is deposited on the surface of the composite material and the strength is enhanced. |
