Design and implementation of the ultrasonic cold forging technology process for improving surface mechanical properties of 6XB2C cold-worked alloy steel tool

Ultrasonic cold forging technology is a mechanical process used to improve surface characteristics of materials by continual striking of the tool in a reciprocating motion. In this study, the proper geometrical shapes of the booster and the horn (collectively called “the concentrator”) were obtained through numerous simulations based on the frequencies produced, the power of an ultrasonic generator (about 20 kHz), and the mechanical vibrations transferred parallel to the axis of the ultrasonic head (transducer, booster, horn, and tool). Furthermore, a pneumatic system was designed using a simulated ultrasonic cold forging technology in order to supply the static load and to prevent tool backlash in the retracting motion. Post-ultrasonic cold forging technology mechanical tests revealed an improved hardness by 17% to a depth of 150 μm and an enhanced smoothness from an initial value of 0.6–0.132 μm in the compressed layers of the surface as a result of using the ultrasonic cold forging technology process.