Size Effect in Micro Machining of Steel Depending on the Material State

In machining of steel changes of the surface and boundary layer are induced through mechanical and thermal loads. The controlled generation of these material modifications, which determine the functional properties of components, is still an iterative process based on experience. An enhanced knowledge on the generation of these modifications can only be gained through fundamental investigations. Therefore, this paper investigates mechanical loads in micro machining of 42CrMoS4 by precision turning with focus on the size effect, occurring due to the ratio of undeformed chip thickness to cutting edge radius. Resulting material modifications are examined and discussed regarding the induced loads.