Effect of support plates on the micro-drilled hole form quality in CFRP laminates

Abstract

Abstract Hole diameter, roundness error, and fiber overlap determine the form quality of a drilled hole on a fiber reinforced composite material. Using support plates is one of the methods to ensure hole form quality. In this study, the effects of support plates on hole form quality in the micro-drilling of CFRP laminates have been investigated. A comprehensive experimental study was carried out under variable cutting speeds and feeds. Three different setups were employed to inspect the effects of the support plates. In the first setup, bare CFRP laminates were drilled. In the second setup, aluminum entry board and phenolic backing board were used. In the third setup, brass entry board and wooden backing board were preferred to inspect the effect of different support plate materials. A large number of holes was drilled per experiment to be able to identify the tool wear effect on the process outputs. Diameter, roundness error, and fiber overlap were measured by using the hole images. Finally, variations of diameter, roundness error, and fiber overlap were evaluated for each setup. It was concluded that support plates improved the process outputs and made the process less sensitive to a change of process variables and tool wear.