Using Harris Hawk algorithm for experimental study on the hole dilation mechanism during Micro-machining (μM) of Graphene nanoplatelets/Carbon fiber (GnP/C) reinforced polymeric composite

Abstract

This article highlights the hole generation mechanism in the Graphene nanoplatelets/Carbon fiber (GnP/C) reinforced polymeric composite. The lower conductivity of conventional carbon fiber reinforced polymer (CFRP) composites restricts the μEDM (Micro Electrical discharge machining) test. This limitation is overwhelmed by adding highly conductive GnP powder in the CFR (epoxy) polymer composites. The generation of the drilled hole is possible through the increase in the electrical conductivity of the samples. During μEDM, in order to examine the quality of machined holes in terms of hole dilation (HD), different process constraints such as voltage (80, 120, 160 V), pulse on time (30, 40, 50 s), and weight percentage of GnP (0.25, 1, 1.75%) are evaluated (HD). The hole dilation was significantly influenced by GnP concentration and voltage alteration during the micromachining process. Analysis of Variance (ANOVA) results confirmed that the GnP concentration (67.51%) was the most prominent factor affecting hole dilation. The high-resolution microscopy test was performed to investigate the hole machined surface and damages occur during the micromachining test. The variation in the thermal nature of carbon fabric and resin generates internal stress between the composite material, which results in micro-cracks developed in the laminates. The varying parameters were controlled and optimized through a recently developed nature-inspired metaheuristics algorithm based on the conduct of Harris Hawk (HH). The optimal parametric condition for the hole dilation is voltage (level 1–80 volt), pulse duration (level 1–30 μs), and GnP concentration% (Level 1–0.25). The findings of the validation test demonstrate the application potential of the proposed Harris Hawk algorithm.