Microstructuring of Surfaces by Two-stage Vibration-assisted Turning

Microstructuring is one suitable method to improve the tribological properties of surfaces. It leads to a reduction in friction and wear, especially in highly loaded tribological contacts. There are several machining techniques to generate microstructures, such as laser beam removal, cold forming, etching or fly-cutting. This paper describes a new method to produce microstructured surfaces more economically, based on a two- staged vibration-assisted turning process. During the first step, a specific microstructure is realized by ultrasonic vibration assistance of the turning tool in the direction perpendicular to the workpiece surface. In the subsequent step, the peaks of the obtained microstructured surface are removed by precision turning without vibration. This results in a plateau-shaped and microdimpled surface. The two-staged vibration- assisted turning process offers the advantage that no additional process is required after finishing because the microstructuring process is already part of the finishing operation. The investigated process can easily be integrated into large batch production, e. g., for tribological optimization of powertrain components.