This research focuses on a comprehensive exploration of the experimental and mechanical aspects of the electrical discharge machining (EDM) process, specifically targeting the machining characteristics of AA2014/Si₃N₄/Mg/cenosphere hybrid composites. The aim is to optimize the process parameters for enhanced machining performance through a combination of testing, optimization, and modelling methodologies. The study examines the effects of key EDM variables—peak current, pulse on time, and pulse off time—on critical output responses: surface roughness (Ra), electrode wear rate (EWR), and material removal rate (MRR). Leveraging an L9 Taguchi orthogonal array experimental design, the impact of controllable factors on these responses is analysed. An integrated approach utilizing MATLAB’s logic toolbox and Mamdani’s technique is employed to model the EDM process, and a multiple-response performance index is calculated using fuzzy logic theory, enabling multiobjective optimizations. Furthermore, a mechanical behaviour evaluation of AA2014/Si₃N₄/Mg/cenosphere hybrid composites is performed through mechanical testing, with a comparison between experimental machining results and predicted values. Scanning electron microscopy (SEM) images reveal the presence of filler reinforcements within the base alloy, displaying an improved microstructure and uniform reinforcement dispersion. An X-ray diffraction (XRD) analysis confirms the major elemental constituents—aluminium, silicon, and magnesium—in the hybrid composites. A microstructural analysis of the hybrid metal matrix composites (MMCs) prepared for EDM showcases closely packed reinforcement structures, circular ash-coloured spots indicating silicon and nitrates, and a fine dispersion of cenosphere reinforcement particles. The study’s outcomes demonstrate a promising application potential for these hybrid composites in various fields.

In this investigation, biodegradable composites were fabricated with polycaprolactone (PCL) matrix reinforced with pine cone powder (15%, 30%, and 45% by weight) and compatibilized with graphite powder (0%, 5%, 10%, and 15% by weight) in polycaprolactone matrix by compression molding technique. The samples were prepared as per ASTM standard and tested for dimensional stability, biodegradability, and fracture energy with scanning electron micrographs. Water-absorption and thickness-swelling were performed to examine the dimensional stability and tests were performed at 23 °C and 50% humidity. Results revealed that the composites with 15 wt % of pine cone powder (PCP) have shown higher dimensional stability as compared to other composites. Bio-composites containing 15–45 wt % of PCP with low graphite content have shown higher disintegration rate than neat PCL. Fracture energy for crack initiation in bio-composites was increased by 68% with 30% PCP. Scanning electron microscopy (SEM) of the composites have shown evenly-distributed PCP particles throughout PCL-matrix at significantly high-degrees or quantities of reinforcing.

The need to develop radar absorbing materials (RAMs) that meet the structural requirement of defense applications is growing swiftly, due to the extensive use of electromagnetic waves in Radar. With the major developments and extensive use of Radar in military applications, the role of Radar absorbing, light weight and high strength structures has become a prime objective for researcher working on the development of RAMs. Various composites have been developed by using reinforcements which are dielectric, such as carbon nanotubes (CNT), magnetic materials like ferrites, that have been extensively used for reinforcement when developing RAMs. Ferromagnetic materials have a high density and can only achieve a narrow bandwidth of absorption. CNT have very good electrical, mechanical and thermal properties and can achieve high dielectric losses but their complex synthesis process is a barrier to commercial applications. Research on reinforcing multi-walled carbon nanotubes (MWCNT) with ferrites and metal oxides can also be extended to the study of thermoplastic polymers like polyether ether ketone and polyaryletherketone, which are gaining prominence in aeronautical applications, owing to their superior mechanical and low moisture absorbing properties. Further research can be carried out on reinforcing metal oxides, as metal oxides, when reinforced with MWCNT enhance the dielectric properties which improve the reflection losses as reported in a few studies.

The organic polymer known as Polypyrrole (Ppy) is synthesized when pyrrole monomers are polymerized. Excellent thermal stability, superior electrical conductivity, and environmental stability are all characteristics of Polypyrrole. Chemical oxidative polymerization was used to synthesize Ppy using Ferric chloride (FeCl₃) as an oxidizing agent and surfactant CTAB in aqueous solution. Oxidant (FeCl₃) to pyrrole varied in different molar ratios (2, 3, 4 and 5). It was found that increasing this ratio up to 4 increases PPy's conductivity. XRD, FTIR, and SEM were used to characterize Ppy. The conductive nature of Ppy was studied by I–V characteristics. The best conductive polymer is studied for the NH₃ gas response.