New tool life criterion for delamination free milling of CFRP

摘要

Delamination occurs in edge trimming of CFRP on the surface plies due to lack of support and is known to depend on feed rate, cutting speed, and tool wear. Burr tools have complex geometries with ill-defined cutting edges and surfaces, and the traditional method of wear measurement is not readily applicable to them. This paper presents and discusses an alternative method for defining tool life for tools with complex geometries, and the application of this method to burr tools is demonstrated. The approach relies on the effect of tool deterioration, rather than the physical wear itself, to define a tool life criterion and a tool life equation. In this study, an indirect technique is used to quantify the tool wear based on delamination. The damage caused by delamination on the composite material undergoing edge trimming operation is quantified in terms of delamination depth and frequency of occurrence per given length. A proper tool life criterion is then defined based on acceptable industry practices, and an empirical tool life equation was developed as a function of cutting speed and feed rate. The new tool life equation was validated by experiments.