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Two new types of electrically-assisted forming(EAF) processes of AZ31B magnesium alloy sheets,i.e., electrically-assisted blanking(EAB) and electrically-assisted sheet upset-extruding(EASUE), are proposed in this paper. During EAB, pulsed current(PC) decreases blanking load and improves blanked surface quality,and higher frequency has a more effective improvement; when the frequency reaches 600 Hz, the whole punched hole fracture is improved to smooth zone. Moreover, EAB does not influence the microstructure and does not induce obvious annealing, and this process is advantageous to the materials that cannot change microstructure.During EASUE, PC can reduce extrusion load and enhance extrusion height, and higher frequency also has a more effective improvement. Both processes indicate that introducing PC can effectively improve the part quality and have an application prospection. 相似文献
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提出一种新的高功率因数的开关变换器,该变换器采用单级结构,单一占空比PWM控制模式,完成功率因校正和输出电压调节双重功能;并对该变换器的工作过程进行了详细分析;最后给出该变换器在电子镇流器电路中的应用。 相似文献