Characteristics of ultrasonic bending of metal plates using a longitudinal vibration die and punch

The characteristics of ultrasonic vibration bending of pure aluminium and anticorrosive aluminium plates of 2.0-3.0-mm thickness using a 19-kHz longitudinal vibration punch and a 27-kHz vibration die are studied. Using an ultrasonic vibration punch or die, the spring-back angle decreases to zero under sufficient vibration amplitude of a die or a punch, the bending angle increases, and bending surface conditions are improved. The hardness of the specimen and elongation of the bending surface decrease, and the roughness of the bending surface is decreased by vibration. The radius of curvature of the bending part doubles compared to the bending part without vibration. The required vibration amplitude for these vibration effects varies due to the material and thickness of the specimen and the total vibration characteristics of the combined die and punch