PURPOSE: To easily manufacture a locally composite and reinforced product having optional component concn. by charging a combined compact, which is obtd. by sintering the combined particles, into recessed part formed by recessing the necessary position in metal product body, and welding these.

CONSTITUTION: The metal product body of aluminum, etc., formed with the recessed part, where the reinforcement is required, is obtd. with aluminum casting, etc. On the other hand, different kinds of particles, such as metal particles of aluminum particles, etc., and ceramic particles of Zr2O3, etc., are brought to collide with each other with mechanical alloying and oxide film on the surface is removed and these are mutually stuck to obtain the combined particles. Successively, these combined particles are sintered to make the combined co pacts. These combined compacts are formed by suitably changing the component concn. Successively, these compacts are sharged into the above recessed part and remelted with high density energy of TIG, etc., and welded to the above metal product body. By this method, the desired local composite and reinforcement can be easily obtd. without using molten metal squeezing method.