To obtain a light metallic material having excellent wear resistance and strength even if being a relatively large one, that the increase of a friction coefficient can be attained and optimum as the stock for a break rotor by forming it of a porous body composed of a hard material and also having pores and allowing it to contain a metallic material whose m.p. is equal to or above the specified temp.

This material is the one contg. a metallic material whose m.p. is ≥1,000°C. As the metallic material, the one having a granular or fibrous shape is used, and in the case of the granular metallic material, the average grain size is preferably controlled to ≤150 μm. As the metallic material, one or more kinds selected from a group composed of Ni, Ni-Al, Ti, Ti-Ni, Fe and Cu are given, and, the metallic material preferably has the electronegativity close to that of light metal composing a composite base material. The hard material is composed of a ceramic sintered body, and the one contg. at least one kind among TiO2, SiC and Al2O3 is preferable. Slurry is poured into a vessel 6 provided with a filtering part 4 and a dehydrating suction port 5 to form a dehydrated body 8, which is sintered to obtain a porous preliminarily formed body.