Extension of empirical specific cutting force model for the process of fine chip-removing milling
Type of publication:
Article in Journal
Title of journal:
The International Journal of Advanced Manufacturing Technology
Volume 88, Issue 9–12
Specific cutting force is a frequently used parameter to classify and describe the energetic environment of mechanical machining operations. It defines the ratio of cutting forces and theoretical chip section during machining. This definition makes it possible to create general technological models for precise process planning. Classical models of cutting forces already indicate that specific cutting force cannot be modelled using a single low-level analytical function due to the marked presence of size effect. The problem is amplified in the case of micro-chip forming, where the relative scale of elastic and plastic deformations in the machined material differ from those experienced in conventional cutting conditions. Previous research proved that boundaries of specific cutting forces can be defined by values of exact uncut chip thicknesses, in which case the sections of specific cutting force may indicate different types of material deforming processes. The aim of current research presented in this paper is to extend the empirical model of specific cutting force for fine chip-removing cutting processes by identifying a new boundary section of uncut chip thickness. Therefore, a new boundary chip thickness was defined based on data obtained with reference to experimental cutting force. New boundary chip thickness follows the so-far proven tendencies of already known section borders and this enables the extension of the validity range of classical approaches presented by specific cutting force models beyond macro-scaled chip forming to micro-scaled chip forming processes. The extension of the model considers the effect of cutting parameters, primarily that of feed rate.