Surface-roughness Improvement in Ultrasonically Assisted Turning

Ultrasonically assisted machining is a hybrid technique based on superimposition of ultrasonic vibration on a movement of a cutting tool. Such vibration with relatively small amplitude – below 20 microns – changes dramatically the response of a machined material to a cutting process. As a result, a significant – in excess of 80% in turning of aerospace superalloys –reduction of average cutting forces is observed together with improvement of surface roughness. The paper presents results of analysis of the effect of ultrasonically assisted turning (UAT) on surface roughness (using a broad range of parameters) for a broad range of metals and alloys – from copper, aluminium and stainless steel to Ni- and Ti-based alloys. The effect of machining parameters for both conventional turning and UAT was investigated to provide an optimum range for each material and its relation to surface roughness.