A New Vibration Device Applied for Two-Dimensional Ultrasonic Polishing of Biomaterials

For the research of the performance of two-dimensional ultrasonic polishing (TDUP) on the biomaterials, a new vibration device was designed. Meanwhile, our aim is to study the mechanism of multiangle polishing to cope with the complex structure of biomaterials. The device is composed of piezoelectric rings, asymmetric transformer, ultrasonic generator, and so on. The structural dimension parameters were optimized by finite element analysis, and especially the groove size on the transformer was discussed in detail. Two kinds of experiments had been conducted to test the performance of the proposed device, including impedance analysis experiments and amplitudes measurement experiments. Furthermore, a mechanical model to explain the principle of the multiangle polishing was set up, which could assist to analyze the influence of different polishing angles in terms of machining. Finally, the machining experiments and multiangle polishing experiments were carried out to verify the effectiveness of the device. Compared with traditional mechanical polishing, the surface roughness is reduced from 235 nm to 140 nm. The results of multiangle polishing experiments indicate that the surface quality of biomaterials will be prominently affected by different polishing angles. In addition, the polishing mechanism will transform owing to the inversion of the normal velocity during the polishing process with the angle increasing. The surface morphology will also be affected. It has been proven that the experimental results agree with the model well.