Previous attempts at drilling of fibrous composites have been challenging due to the limited mechanical properties and presence of severe delamination damage at the top and bottom surfaces of the drilled hole. With the recent introduction of hybrid carbon/glass fiber reinforced polymer (HFRP) composites in both research literature and industrial applications, the need for evaluating their drillability is inevitable prior to their final usage. This is mainly because of the unique properties of HFRP composites as compared to the single-type FRP composites. Therefore, this paper aims to present a research initiative that will elucidate the high-range parametric effects of drilling control factors on delamination damage and surface quality. Taguchi methodology and statistical analysis of variance were applied to determine the performance of the drilling process. Experimental results revealed that delamination damage and surface quality values were strongly influenced by the feed and special tool geometries rather than the spindle rotational speed. Changes in the feed are likely to contribute to increase in the thrust force and strain rate on the workpiece. Confirmation tests have shown the closeness of the calculated values via a regression model and additive rule with the experimental values. This indicates that the regression model from the response surface can be employed to estimate delamination damage and surface roughness during drilling of HFRP composite.

This article describes an experimental investigation on end milling of glass fiber reinforced polymer (GFRP) composites using uncoated tungsten carbide tool. A series of experiments were carried out to evaluate the machinability of GFRP composites in terms of tool wear, tool useful life, machining quality, and machining forces. Machinability data were evaluated in the form of Taylor's equation in order to predict the tool performance while machining this composite material. The useful life of the cutting tool was found to be well described by the Taylor's equations. The cutting speed was identified as the key parameter in influencing the tool life followed by feed rate and fiber orientation. Machining force variations were constantly monitored during end milling tests, which are mainly attributed to the growth of tool wear and fiber orientation.