a method of making a rotor is provided . the method includes mixing aluminum and carbon nanotubes ; forming the mixture into an aluminum - carbon nanotube composite conductor bar ; providing a laminated steel stack having a plurality of longitudinal slots ; placing a plurality of the conductor bars in the longitudinal slots , first and second ends of the plurality of conductor bars extending out of the longitudinal slots ; placing the laminated steel stack with the plurality of conductor bars in a casting mold having cavities for a pair of end rings wherein the first and second ends of the plurality of conductor bars extend into the cavities ; and filling the cavities with aluminum , aluminum alloys , an aluminum composite , or combinations thereof . rotors made from aluminum - carbon nanotube composite are also described .