Drilling Studies on Sustainable Lightweight Hybrid Polymer Matrix High Performance Nanocomposites

Worldwide, engineers are exploring the possibility of using polymer composites in their quest for lightweight materials. In an effort to create polymer composites that are less harmful to the environment, the use of biodegradable polymers has been investigated in recent years. Injection molding was used to create a biodegradable polymer composite containing 20 wt.% vetiver fibers (VFs) and 2 wt.% nano-silica (nSiO2) obtained from pearl millet. Parts for unmanned aerial vehicles, interior cabin panels, seating structures, and secondary structural components were made of this composite. Desirability analysis was used to examine and optimize machining (drilling) studies that were designed according to Taguchi's design (L9 orthogonal array). Surface roughness (Ra) and delamination factor (DF) were taken as outputs, while spindle speed (SS) ranging from 1000 to 3000 rpm, feed rate (FR) from 15 to 45 mm/min, and drill diameter (DD) from 6 to 10 mm were used as inputs. The developed regression models are further optimized using a non-traditional meta-heuristic technique, frog leaping algorithm (FLA), which is inspired by frog jumping. According to the results, the DD is the second most important factor affecting DF and Ra, after the FR, whereas SS has a very little impact. Increased delamination at the margins of holes and poor surface quality are results of increased thrust force caused by a higher FR, which in turn promotes fiber-matrix debonding, crack propagation, and interfacial pull-out.