Surface Generation in Ultra Precision Single Point Diamond Turning of Aluminum

INTRODUCTION Ultra precision single point diamond turning is a very promising tool based manufacturing technology because of its reliability, productivity and wide range of applications. However, with the reduction in cutting dimensions compared to traditional precision machining, the process physics differs substantially. This is largely because of size effects and increased surface finish expectations. In this study, an effort will be made to better understand the effect that material micro-structure plays on the machining process and to explain the physics of surface generation in ultra precision machining of aluminum alloys. In machining studies the surface roughness is observed to decrease with a decrease in the undeformed chip thickness (feed) but it is consistently higher than the theoretically predicted value. To explain and understand this fly-cutting tests have been performed with various undeformed chip thicknesses. The cutting tools were studied under the SEM before and after machining to ensure that the tool wear was minimal. Chips were also studied under an SEM and a strong presence of ploughing action (Serrated chip) was observed near the valley where the undeformed chip thickness is very small.