Effect of UV rays heating on the mechanical and drilling properties of epoxy hybrid composites: An investigation

This research investigates the optimization of natural fiber-reinforced polymer matrix composites (PMCs) for drilling applications, addressing the inherent anisotropy of these materials. A range of natural fibers, such as jute, banana, flax, kenaf, paddy straw, Grewia serrulatta, cotton, human hair, and sisal, were used to fabricate PMCs, and their mechanical properties (flexural and tensile strength) were assessed. To enhance mechanical stability, copper (Cu) particles were incorporated into all composites. Drilling experiments are designed using L16 Orthogonal Array, were performed with UV-assisted heating to study the effects of composite type, drilling speed, feed rate, and machining zone temperature on the drilling process. The drilling process parameters are optimized through Preference Ranking Organization Method for Enrichment Evaluations II (PROMETHEE II) technique. Among the use of different fibers, Grewia serrulatta produces the highest flexural and tensile strengths of 850 MPa and 550 MPa, respectively, than other fibers, as well as third and fourth highest flexural strength obtained with Flax and sisal Grewia fibers, respectively. The flax fiber produces 741 MPa flexural strength which is 58% higher than jute fiber, and Grewia fiber creates 650 MPa flexural strength which is 32.1% higher than the jute fiber strength. Based on PROMETHEE II, kenaf fiber composite, 25 rpm drilling speed, 70 mm/min flow rate and 40°C, is suggested obtaining the better quality hole. According to the analysis of variance of preferences values, type of composite and feed rate of drilling machine contribute the quality of hole around 51.65% and 15.80%, respectively. Furthermore, scanning electron microscope image studies are conducted on the exterior of drilled work piece to recognize the effect of heating and fibers impact on drilling quality.