Design and fabrication of a skew-typed longitudinal-torsional composite ultrasonic vibrator for titanium wire drawing

In this paper, a new longitudinal-torsional (LT) hybrid vibrator driven by two longitudinal ultrasonic transducers is proposed for ultrasonic-assisted wire drawing. The two identical transducers were vertically installed on the two side surfaces of a transformer, however, with an offset distance (Δx) and stagger angle (α) between their axes. Therefore, the transformer could synthesize and amplify the vibration of the two transducers to produce an LT composite vibration. Harmonic and transient simulations were performed in ANSYS to investigate the dynamic characteristics and frequency-dependent sensitivity of the vibrator. Δx and α between the transducers were subsequently optimized to maximize the output amplitude. Based on the finite element analysis (FEA) results, a prototype was manufactured with an electrical circuit developed for impedance matching. The vibrator generates an LT composite vibration with a measured longitudinal amplitude of about 20 μ m when driven by a voltage of 400 V_p-p , 19.597 kHz. The result is consistent with the FEA prediction, which indicates a new method of combining two different forms of ultrasonic vibration.