To produce partially compounded light metallic parts, even if being a relatively large one, capable of exhibiting excellent wear resistance and strength, furthermore capable of attaining the increase of μ, moreover capable of smoothly maintaining surface properties over a long period and optimum as the stock for a break rotor in particular and to provide a preliminarily molded body for producing this partially compounded light metallic parts.

The preliminarily molded body is the one used for producing partially compounded light metallic parts in which at least the part of the sliding face is compounded, which is composed of a hard material and also is a porous body having pores, and the hard material is obtd. by sintering the raw materials contg. (1) TiO2 particles, (2) ceramics short fibers and/or whiskers and (3) SiC particles having 20 to 100 μm average particle size.