To obtain a preform of a reinforcing material for a metal-base composite material capable of forming a homogeneous composite maternal free from segregation of an alloying element and capable of maintaining grain refining effect by increasing strength with TiO2 as an inorg. binder.
A reinforcing material in the form of particles, whiskers, fibers, etc., is uniformly mixed with about 0.5-20wt.% anatase type TiO2 particles as an inorg. binder and the resultant mixture is dry-pressed in a prescribed shape and heated to about 1,250°C in the air with a resistance heating furnace, etc., to form the objective preform. The surface of this preform 1 is coated with a suspension of TiO2 as an infiltrating aid. The preform 1 is then put on the bottom 2 of a steel crucible 3 having an opening with the TiO2 coated surface upward, Mg 4 is melted by heating to about 730°C with the heater of a furnace 6 and a mixture of CO2 with 0.3% SF6 is fed as protective gas from a pipe 8. The molten Mg 4 is allowed to infiltrate into the preform 1 and the objective metal-base composite material is obtd.
KANEDA HIROMITSU
SANO YOSHINOBU
