An Investigation of the Process Parameters Choice Criterion for Cutting Force Coefficient Identifications in Slot Milling

Milling force prediction is crucial for assessing the state of machining processing and improving piece quality. Most of the prediction models are depended on cutting force coefficients for the milling force. However, there is no accepted choice criterion for cutting force coefficient identifications test, especially how to choose appropriate process parameters. The exact impact of process parameters on the identifications has hardly reported before in slot milling. In this study, a milling force test system was set up, and the spindle speed, tool diameters, milling depth, number of tool teeth, and machining characteristics of the workpiece were taken as test factors in the slot-milling. It is revealed that the identifications of the cutting force coefficient decrease with the increase of the tool speed, but are correlated with the tool diameter positively. While the dynamic cutting force increases with intensified milling depth, a larger milling depth may lead to an expansion of the contact area between the tool and the workpiece. Also, more workpiece material is removed simultaneously, and the milling depth and the number of tool teeth have almost no effect on the identifications. In addition, it is also found that materials with better milling performance, such as aluminum alloy, exhibit larger identification errors, which may be related to the "sticky knife" phenomenon during the process, compared with difficult-to-machine materials. The findings can provide a good reference for cutting force coefficient identification test.