Fundamental Analysis of Process Performance in Conventional and Ultrasonic-Assisted Ultra-Precision Turning of Graphite Materials using Single Crystal Diamond Tools

In ultra-precision turning of graphite for air bearing applications, single crystal diamond (SCD) tools exhibit significant potential for achieving the low surface roughness required for functional bearing surfaces. However, uncontrolled crack propagation and breakout behavior remain major challenges in graphite turning. Ultrasonic-assisted turning mitigates these issues by reducing tool-workpiece contact time by 80 %, enabling more controlled stress conditions, enhanced cutting stability and overall performance. This study compares conventional and ultrasonic-assisted turning processes, evaluating process performance based on surface roughness values. The findings show suitable parameters and strategies, offering valuable insights for improving surface quality in ultra-precision turning of graphite.