Wear Study of Coated Mills during Circumferential Milling of Carbon Fiber-Reinforced Composites and Their Influence on the Sustainable Quality of the Machined Surface

Abstract

Composite materials made of fiber-reinforced plastic laminates are highly susceptible to surface damage caused by wear during contour milling, especially with inappropriate tool and cutting material properties. Improper choice of tools and cutting conditions lead to delamination between applied layers, thermal damage of materials in the polymer matrix, and reduction of the edge quality of cutting tools. The study was devoted to circumferential milling of twill-bonded CFRP (carbon-fiber-reinforced polymer) sheets with a focus on cutting forces and tool flank face wear, including their effect on the machined surface structure, roughness, and topography of the laminate. The main objective of the study is to investigate the feasibility of applying conventional coated tools, which are not primarily designed for milling CFRP, in comparison to a dedicated DLC (diamond-like carbon) coated tool, due to economic and distribution availability and the possibility of providing suitable cutting conditions during milling. The study provides results confirming the possibility of using conventional tools for machining CFRP and provides relevant experimental results that can be implemented for optimal tool selection, tool life criteria, cutting conditions, and machining strategies including low energy consumption. The best values of the investigated parameters were obtained when using the ECSSF (instrument designation) tool with DLC coating.