Abstract: Disclosed are a method of manufacturing a billet used in plastic working for producing a composite member and a billet manufactured by the method. The method includes (A) ball-milling powders of two more materials to prepare a composite powder and (B) preparing a multi-layered billet containing the composite powder. The multi-layered billet includes a core layer and two or more shell layers. The shell layers except for the outermost shell layer are made of the composite powder. The outermost shell layer is made of a pure metal or metal alloy. The composite powders contained in the core layer and each of the shell layers have different compositions. The method has an advantage of manufacturing a plastic working billet being capable of overcoming the limitation of a single-material billet and enabling production of a characteristic-specific composite member such as a clad member.

Abstract: Disclosed are a method of manufacturing an aluminum alloy clad section, and an aluminum alloy clad section manufactured by the method. The method includes preparing a composite powder by ball-milling aluminum powder and carbon nanotubes, preparing a billet from the composite powder, and subjecting the billet to direct extrusion using an extrusion die. The method is simple in procedure and uses simple equipment because it is based on direct extrusion which is suitable for mass production. Thus, the method is capable of producing a lightweight high-strength functional aluminum alloy clad section having a competitive advantage in terms of price over conventional aluminum alloy clad sections.

Abstract: The present invention provides a method of manufacturing a single-walled-carbon-nanotube-reinforced metal matrix complex material. The method includes (a) manufacturing a complex powder by performing ball milling of a metal powder and a single-walled carbon nanotube powder, and (b) manufacturing a metal-carbon-nanotube complex material by spark-plasma-sintering (SPS) the complex powder manufactured during step (a). According to the method of manufacturing the single-walled-carbon-nanotube-reinforced metal matrix complex material according to the present invention, in order to manufacture material parts requiring high strength and abrasion resistance, the single-walled carbon nanotube powder is added to various metal matrixes and ball milling is performed, thus manufacturing a complex powder having uniform dispersity.