Drilling Characteristics of Sisal Fiber-Reinforced Epoxy and Polypropylene Composites

Natural fiber composites have attracted global attention due to their lightweight, low-carbon footprint characteristics as well as good mechanical properties. Due to these distinct advantages, the application spectrum of these composites has grown at an unprecedented rate. These composites are used for making a wide variety of sophisticated engineering products; therefore, certain degree of machining operations is necessary for assembly purposes. Drilling is an indispensable machining operation that is frequently performed for making of holes to facilitate assembly of several components into an intricate part. In the present research endeavor, the drilling behavior of unidirectional sisal-epoxy and sisal-polypropylene composite laminates has been experimentally investigated. Chip formation characteristics in the context of both thermoset and thermoplastic natural fiber composite laminates have been discussed. Further, the analysis of drilling force signals has been reported and the mapping of drilling forces has been proposed. Influence of drill geometry, feed, and spindle speed on drilling forces and a comparative analysis of damage characteristics of drilled hole have also been reported. From the current research work, it has been established that the tooling requirement for drilling of composite laminates under investigation is substantially different.