Method of manufacturing cooling pipe for powertrain of electric vehicle and cooling pipe manufactured thereby

A method of manufacturing a cooling pipe for a powertrain of an electric vehicle, the method comprising:

• preparing a powdered composite material by ball-milling aluminum alloy particles and carbon nanotube particles;
• preparing a multilayer billet containing the powdered composite material, wherein the multilayer billet comprises:
• a can-shaped first billet serving as a second shell layer,
• a second billet disposed inside the can-shaped first billet and serving as a first shell layer, and
• a third billet disposed inside the second billet and serving as a core layer,
• wherein the first billet is made of aluminum,
• wherein the second billet and the third billet comprise the powdered composite material, and
• wherein the second billet comprises 0.09 to 10 parts by volume of the carbon nanotube particles with respect to 100 parts by volume of the aluminum alloy particles, and the third billet comprises 0.08 part by volume of the carbon nanotube particles with respect to 100 parts by volume of the aluminum alloy particles;
• and
• extruding the multilayer billet to prepare a pipe-shaped extrusion.