PURPOSE: To obtain a high strength composite material by forming a boundary layer of B and Al mixture oxide on a boundary between a fiber containing a specified quantity of Al2O3 and a molten Al so as to improve wetting and binding between the fiber and Al.
CONSTITUTION: A composite material is formed by using a fiber containing ≥30 wt.% Al2O3 as a reinforcing material and Al or an Al alloy as a matrix. In this case, to a boundary between the fiber and the molten Al or the Al alloy, a boundary layer of B/Al mixture oxide is formed. The boundary layer is formed by applying alumina-fiber coating to a material consisting of B, B2O3, boron oxide precursor, B added Al alloy, etc. Ammonium pentaborate, ammonium biborate, orthoboric acid, etc., are used for a boron oxide precusor. These precusors form B2O3 by thermal decomposition after coating. By this method, an alumina fiber-reinforced Al or Al alloy matrix composite material, in which wettability and binding between the reinforcing material and the matrix are improved, is obtained.
CHIYANAKIYA MISURA
KAARU BEFUAAZU
