The method of ultrasonical combined machining micro-structures of is advanced.The micro-machining mechanism and characteristics of ultrasonical combined machining are analyzed.Several kind cathodes with different sections are manufactured by combined electro-discharge micro-machining.The micro-machining system is built and improved.The micro-structures are manufactured by electrical combined ultrasonical machining.It is proved that ultrasonical machining is an effective way for the micro-structures of hard ...