PURPOSE: To efficiently obtain a product excellent in joining strength between a metal matrix composite and a metallic sheet even in the case of large-sized product, long-size product, or product of complicated shape by forming a porous formed body, which is incorporated to a clad material and into which molten light metal is allowed to infiltrate, by using a specific material.
CONSTITUTION: A porous formed body containing inorganic reinforcement, fine pieces of metal fluoride, and metal(M) excellent in wettability to molten light metal is formed. This formed body is abutted on a metallic sheet for forming a clad material, and, in the above state, at least a part of the formed body is brought into contact with molten light metal and this molten metal is allowed to infiltrate into the formed body practically without pressurization. Since respective oxide films on a molten metal surface and a metal surface can be removed by metal fluoride by the above method, the wettability of the molten metal to the reinforcement and the metallic sheet can be easily produced and also metallic elements in the molten metal are allowed to diffuse and infiltrate sufficiently into the surface of the metal sheet. Moreover, the molten metal can be allowed to infiltrate sufficiently into the formed body via the metal (M) owing to the presence of the metal(M), and further, heat is generated by the reaction with the molten metal, by which the wettability of the molten metal to the reinforcement and the metal sheet can be improved to a greater extent.