Ultrasonic-assisted technologies have enhanced the existing limits of conventional cutting processes of brittle metal-based materials. Superimposing the infeed with an adapted ultrasonic vibration enables the reduction of the machining forces. This, in turn, leads to an diminished tool wear and longer tool life. Furthermore, an increase in removal rates can be achieved. This paper presents cutting tests on granite, which have been performed to evaluate the applicability of the ultrasonic assistance for the machining of stone. Contrary to the state of the art, this study focused on carbide metal and polycrystalline diamond cutting tools with geometrically defined cutting edges. The ultrasonic frequency was maintained at 20 kHz. Different oscillation amplitudes up to 25 µm were applied to reduce process forces in comparison to the conventional machining. The observation and, subsequently, measurement of the wear behavior of the tools according to the process parameters were carried out by using a stereomicroscope and a 3D measurement system.
The pressure to be innovative puts especially high demands on the cutting process with regard to production costs and resource efficiency. Hence, the early recognition of potential for improvement and it's implementation is of significant importance. High strength materials require innovative process and machining concepts that are in principle energy and resource efficient (Treppe 2011).
In addition to the continuous development of materials, increasing quality demands and changing economic conditions require a steady advancement of the cutting processes. If an optimization is insufficient or pushes a previously used cutting process to its limit, hybrid manufacturing technologies offer an important approach for enhancement.
In the metal processing industry, machine tools are therefore increasingly supplemented by additional manufacturing technologies. Furthermore, different hybrid-based concepts are investigated. While laser-assisted cutting causes a heating of the workpiece and therefore a strength reduction in the structure, the mechanism of ultrasonic-assisted cutting is based on an optimized chip-formation and the correlating reduction of friction and heat. Consequently, the ultrasonic assistance diminishes the necessitated cutting energy and hence enables an efficient cutting process (Neugebauer et al. 2009 and Zäh & Löhe 2012).
