Influence of Ultrasonic Burnishing Technique on Surface Quality and Change in the Dimensions of Metal Shafts

This paper presents ultrasonic burnishing as a mechanical surface treatment for improving the quality of rotating shafts. Ultrasonic burnishing is a modern method for finishing workpieces to produce a good surface quality. This process improves the surface quality and increases the surface hardness of the workpiece, and the surface roughness of the workpiece improves. As a result, wear resistance and fatigue life increase. Furthermore, these improvements are achieved without expensive equipment or long processing times. In this paper the influence of the ultraburnishing technique on the change in diameter and its effects on the out-of-roundness of rotating shafts are investigated. This paper also takes a look at the magnitudes of the improvement of the surface roughness as a result of using ultrasonic burnishing. Three different materials, aluminium, 34-CrNiMo6 tempering steel, and S355J2 structural steel, are examined. The results showed that ultrasonic burnishing is a treatment that improves the quality of components. Ultrasonic burnishing also has a reducing effect on the final diameter and out-of-roundness and increases the hardness of the workpiece. It can also be stated that the material of the workpiece does not have a significant effect on the magnitude of the reduced surface roughness values. 1. Introduction The ultrasonic method investigated in this paper is mainly used for finishing metal surfaces. The method is based on forging at an ultrasonic frequency. The ultrasonic transducers convert high-frequency electrical power into ultrasonic vibration which leads to the finishing head of the ultrasonic tool to forge the surface of the material with the desired impact rate of up to over 20,000 impacts per second. The finishing head is hard metal and is placed at a right angle to the work piece. The finishing head is attached to a spring system which provides a constant contact force. The spring can be compressed to the desired extent, leading to higher contact forces as the deflection increases [1–4]. Other mechanical surface treatments such as the burnishing ball technique have been widely used to improve the physical-mechanical properties of metallic components [1]. As a consequence of plastic deformations, compressive residual stress states, work hardening, microstructural alterations, and a favourable roughness are produced, improving fatigue strength and wear resistance [1]. This mechanism is performed by a rolling element that moves over the toolpaths on the surface, applying a regular compression force at the same time. According to