An investigation on high speed drilling of glass fibre reinforced plastic (GFRP)

Abstract

High speed machining is now recognised as one of the key manufacturing technologies for higher productivity and throughput. An experimental investigation has been performed on GFRP using carbide drill with different drill geometries, namely standard twist drill, double cone drill, Zhirov-point drill and multifacet drill. A series of experiments are conducted using wide range of cutting parameters namely, speed and feed rate. Thrust force and surface roughness are measured and studied in the test trials. The analysis of variance (ANOVA) technique is employed to investigate the cutting characteristics of different drilling geometries. Relation between spindle speed and feed rate on thrust force and surface roughness is established. It is found that Zhirov point drill and multifacet drill could be used at high spindle speed which generates less thrust force. Surface finish of the drilled hole could be achieved to 2-6.1 μm with Zhirov drill. The investigation reveals the use of special geometry drills which improve the hole quality in GFRP composites drilled at high spindle speed.