A mechanistic cutting force model with consideration of the intrinsic and geometric size effects decoupled

In machining processes, the specific cutting energy increases nonlinearly as the uncut chip thickness decreases. This phenomenon is called the size effect and can be classified into two types by its cause—geometric and intrinsic. The geometric size effect is caused by the decrease of the effective rake angle with the decrease of the uncut chip thickness when the tool has a finite radius of the cutting edge. The intrinsic size effect results from the nature of the material, in which the resistance against plastic deformation (flow stress) increases as the length scale of the material deformed decreases. In order to improve the prediction accuracy of a cutting force model in micro-machining, it is important to understand each of these size effects and reflect them into the cutting force model accurately. In this regard, this study develops an experimental method to decouple the geometric and intrinsic size effects and models them individually. Based on this, a mechanistic cutting force model including the geometric and intrinsic size effects in separate terms is constructed and compared to the existing models which do not consider them separately.