Analysis of Microstructures and Defects of the Thixoformed Cu rotor for High Efficiency Electrical Motors

반응고 성형법에 의해 제조된 고효율 전동기용 Cu-Rotor의 미세조직 및 결함 분석

Rotor in small-medium induction motor has been usually manufactured by aluminum diecasting. In order to improve efficiency of induction motors, however, it is desirable that pure aluminum is replaced by high electrical conductivity copper alloy. For this purpose, a rotor is thixoformed with Cu-Ca alloy. Thermomechanical processing(TMP) is carried out to modify the semi-solid microstructure of the alloy and final microstructures and filling defects of thixoformed Cu- rotors are investigated. The characteristics of thixoformed Cu-rotor such as motor efficiency and torque are compared with those of Al rotor.