The unregulated burning of agricultural waste post-harvest remains a persistent, inadequately addressed environmental issue that substantially contributes to air pollution, greenhouse gas emissions, and the depletion of valuable biomass. This research involves the extraction of natural fibers from the banana crop agro-waste. Nowadays, natural fibers have attracted attention in the engineering sector due to their renewability, biodegradability, recyclability, and abundance. These fibers possess certain limitations, including poor thermal conductivity, high moisture absorption, and weaker fiber-matrix adhesion. To address these issues, researchers have employed various surface modification methods, including saline, alkaline, and sodium bicarbonate treatments. In the current study, banana fibers were subjected to an innovative, eco-friendly treatment process using Sapindus mukorossi and citric acid as environmentally friendly alternatives to conventional chemical treatments. The treatment was applied for varying durations of 25, 50, 75, 100, and 125 h. Traditional chemical treatments are known to have adverse effects on both human health and the environment, making this natural approach a sustainable option. The efficacy of the eco-friendly treated fibers was analyzed using Fourier transform infrared spectroscopy, thermogravimetric analysis, and lignocellulosic composition. The study revealed improvements in both structural and thermal properties as the treatment time increased. The non-cellulosic content was entirely eliminated post-treatment, hemicellulose was reduced by 50%, and lignin was decreased by 12.5% following 125 h of treatment. The surface morphology of the fibers was examined using scanning electron microscopy. The treated fibers demonstrate enhanced structural stability and surface characteristics, indicating strong potential for sustainable composite manufacturing and lightweight engineering applications.

Abstract Miniature features such as micro-channels and micro-holes can be easily fabricated on intricate and fragile materials namely glass, superalloys, composite, and steel by using a hybrid and advanced machining process like electrochemical discharge machining (ECDM). Recently, various researchers have done further hybridization of ECDM process with the incorporation of ultrasonic, magnetic, vibration, rotary etc for further improvement in the process. This study investigates the influence of laser assistance on the powder-mixed electrochemical discharge machining (PMECDM) process to enhance its performance. The results indicated that incorporating a laser beam during the ECDM process led to improvements in key output parameters such as material removal rate (MRR), hole taper, and overcut. Assistance of low power LASER beam rises the electrolyte temperature, which in turn improves the machining performance. A comparison and experimental study were carried out between LA-ECDM and PMECDM. The machining of carbon fiber reinforced polymer (CFRP) composites was carried out by considering process parameters such as electrolyte concentration, duty cycle, tool travel rate (TTR), and tool rotation speed. Studies have shown that increasing the duty cycle and electrolyte concentration leads to higher values of output responses such as MRR, hole taper, and overcut. Moreover, these output responses were found to decrease with an increase in the TTR. Additionally, overcut and hole taper tend to rise with higher duty cycle and electrolyte concentration, while both are reduced as the TTR increases. In comparison to the PMECDM process, the LA-ECDM method resulted in enhancements of 16%, 11%, and 7% in MRR, taper, and overcut, respectively. The optimal parametric setting such as 90% duty cycle, 1 mm min −1 TTR, 360 RPM, and 25% electrolyte concentration was obtained through TOPSIS-Entropy optimization technique for output characteristics. LA-ECDM exhibited better dimensional accuracy, circularity, and surface integrity as seen by SEM images. Furthermore, SEM analysis revealed the formation of a stable and thin gas film during the LA-ECDM process, which contributed to a smoother surface finish and consistent fiber cutting along the machined area.

This study explores the use of mixed electrolyte of Citric acid (lemon solution)-NaCl as an eco-friendly alternative for Ultrasonic Assisted Rotary Electrochemical Discharge Machining (UA-RECDM) of borosilicate glass. Experiments were performed by varying citric acid concentration in the range of 10–50

This study presents a novel implementation of ultrasonic-assisted rotary electrochemical discharge machining for precision micromachining of borosilicate glass by integrating ultrasonic tool vibration, workpiece rotation, and silicon carbide abrasive-assisted electrolytes. The influence of varying silicon carbide concentrations (0.5-2.0 wt.

Natural fiber-reinforced biocomposites have gained the attention of researchers in the fields of household, aerospace, and automobile due to their low density, biodegradability, and recyclability. Regardless of these advantages, biocomposites possess certain limitations, such as moisture absorption, weak fiber-matrix adhesion, and poor flammability. To address this issue, fiber surfaces were modified in the present research investigation with a novel electroless copper coating process. Copper-coated fibers were reinforced with poly-lactic acid using an injection molding process, and the influence of coating on the overall performance of the biocomposites was examined via water absorption, flammability, and mechanical properties. After copper coating, the water absorption and rate of burning were improved by 77.5 % and 75 %, respectively. The mechanical properties of biocomposites were enhanced by 18 %, 15.7 %, and 24.3 % for tensile, flexural, and impact strength, respectively. Furthermore, the tensile modulus and flexural modulus of coated biocomposites were enhanced by 11.1 % and 9 %, respectively. The elemental composition, phase identification, chemical structure, and crystalline characteristics of coated fibers were observed with the help of EDS mapping, FTIR, and XRD analysis. EDS mapping observed the presence of copper on the surface of the coated fibers, whereas the scanning electron microscopy of biocomposites observed fiber clusters, fiber pull-outs, and fiber and matrix breakages.

In the recent duration, the research community was attracted towards environmental protection and health-related issues of working human operators through green and sustainable manufacturing. Electrochemical discharge machining (ECDM) was proven to be a potential contender to machine any type of material regardless of its characteristics because of its versatile applications in micro electro-mechanical systems, laboratory-on-chip devices, micro-fluidic devices, and the aerospace industry. Researchers had improved the performance of the ECDM process using different techniques, but the environmental aspects of the process were the least reported. The research paper highlighted the environmental aspects of the ECDM process in terms of fume mass concentration, morphological analysis of fume particles, particle size, and chemical composition of airborne particles. Fume mass concentration (FMC) was evaluated by changing the concentration of the electrolyte and the duty cycle. The obtained FMC varied from 28.7 to 109 mg m− 3 with a change in the concentration of the electrolyte from 20 to 50 μ m. Metallic, toxic, and carcinogenic elements, namely copper, nickel, aluminum, titanium, magnesium, carbon, silicon, chromium, and others, were found during energy dispersive spectroscopy (EDS) analysis, which might have affected the health of human operators.

Electrochemical Discharge Machining (ECDM) is broadly accepted for the machining of both conductive and non-conductive materials. However, the tool wear during machining significantly affects the process accuracy. An attempt has been made to explore the behavior of the tool variables, such as tool rotation, tool feed rate, tool immersion depth, and cryogenic-treated tool on tribological parameters, viz., axial tool wear during ECDM of carbon fiber-reinforced polymer composite. Experiments are conducted using a tool rotation of 500-700rpm, a tool travel rate of 200-400 mu m/min, and a tool immersion depth of 1-2mm, with deep cryogenic-treated and non-treated tool electrodes. The tool wear dominantly decreases with increases in tool rotation, tool feed rate, and tool immersion depth during machining. The surface characteristics of the tool and the machined hole were investigated using scanning electron microscopy (SEM). SEM micrographs clearly illustrate a significant reduction in axial tool wear, with deep cryogenic-treated electrodes exhibiting 90 mu m of axial wear compared to 1640 mu m for untreated electrodes, reflecting an improvement of approximately 95%. Additionally, machining accuracy is enhanced, as indicated by an 11% reduction in both overcut (from 350 mu m to 310 mu m) and taper (from 44 mu m to 39 mu m) in the machined hole. These improvements highlight the effectiveness of deep cryogenic treatment in enhancing tool performance and precision. From a tribological perspective, the improved wear resistance of the cryogenically treated tool electrode reduces frictional losses, leading to enhanced machining accuracy and prolonged tool life. Therefore, a deep cryogenic-treated tool electrode with parametric conditions of a tool rotation speed of 700rpm, a tool travel rate of 400 mu m/min, and a tool immersion depth of 2mm is highly recommended for the micro-machining of carbon-reinforced polymer composite.

Composites made of carbon fiber reinforced polymer (CFRP) are an advanced category of materials recognized for their outstanding attributes, including low density and high load-bearing capability. Due to these characteristics, CFRP composites find extensive applications in industries like biomedical, sports, aerospace, and automotive. However, machining CFRP using electrochemical discharge machining (ECDM) presents challenges, including delamination, excessive overcut, and low material removal rate (MRR). To address these issues, powder-mixed electrolyte processes, such as powder-mixed electrochemical discharge machining (PMECDM), have gained popularity. PMECDM has been shown to enhance machining outcomes for CFRP, leading to improved MRR, reduced overcut, and better surface quality. Experiments were conducted using an L16 orthogonal array, considering four key input parameters like concentration of electrolyte, tool rotational speed, Tool Travel rate (TTR), and duty cycle. Results indicated that PMECDM outperformed conventional ECDM, with MRR improving by 15% and overcut decreasing by 8%. To optimize machining parameters for the best output characteristics, the TOPSIS-Entropy method was employed. The optimal settings for maximizing MRR and minimizing overcut were identified as 35% electrolyte concentration, 480 RPM tool rotation, 90% duty cycle, and a tool feed rate of 1.0 mm min(-1). Additionally, SEM examination of the hole wall surfaces and machined holes confirmed that PMECDM machining produced CFRP composites with a smoother and cleaner surface finish.

Carbon fibre reinforced polymer (CFRP) has an outstanding characteristics such as high strength, low weight, and high resistance to the temperature, and it exhibits various applications in the field of aerospace, automotive, sporting goods, defence and marine products. For CFRP, drilling of the holes remains the most common secondary machining operation. Despite its widespread use, difficulties such as burring, poor surface quality, poor geometrical features and delamination continue to limit its use. Ultrasonic assisted rotary Electrochemical discharge machining (UR-ECDM) appears as a novel machining technology for drilling holes in composite materials. The present study focusses on the simulation as well as the experimental study of the CFRP in terms of material removal, circularity error (CE), and surface roughness (SR). The multi-spark finite element model is developed to analyze the machinability of the CFRP. The plots of the temperature distribution within the CFRP are utilized to predict the material removal which is further validated using the experimental results. A fair consensus has been noticed between the simulation and experimental results. The effect of various input parameters on response characteristics is also discussed. Results demonstrated that UR-ECDM process can be used to drill holes in CFRP with excellent geometrical features.

In the present research investigation, a novel natural treatment process using Sapindus mukorossi and citric acid was developed for surface modification of fibers to replace conventional chemical treatments. For comparative analysis, banana and bagasse fibers were treated with natural and chemical treatment processes prior to being fed into injection molding with polylactic acid for biocomposite fabrication. A life cycle assessment was conducted to evaluate the environmental impacts of treatment processes using the ReCiPe midpoint (H) methodology. The functional unit was "per kg" of the manufactured biocomposite, and the boundary was chosen to be cradle-to-gate. The major impact category results revealed that chemical treatment generates the highest emission (7.623E-01 kg CO2-Eq), while natural treatment decreases the emission to a minimum of 5.3 % and a maximum of 87 %. The effects of treatment processes on biocomposites were examined using Fourier transform infrared spectroscopy, thermogravimetric analysis, water absorption, and mechanical characterization. In comparison to chemically treated fiber reinforced biocomposites, naturally treated fiber biocomposites improved their tensile and flexural properties by 11.8 % and 6 %, respectively, while their water absorption increased by 58 % and 62.2 %, respectively. Moreover, naturally treated banana fiber biocomposites observed the maximum tensile properties (strength: 43 +/- 2.08 MPa, modulus: 3.69 +/- 0.18 GPa) and flexural properties (strength: 86.8 +/- 3.73 MPa, modulus: 5.56 +/- 0.29 GPa). Scanning electron microscopy was also used to investigate the surface properties of biocomposites.

The emergence of electrochemical discharge machining (ECDM) has demonstrated as promising method for creating micro-holes in tough and brittle materials like glass. This technique employs localized Joule heating of material to facilitate its controlled removal. Nonetheless, there are still several critical issues that need to be tackled during drilling of micro-holes. These are limited machining depth (MD), pronounced hole taperness (HT), susceptibility to thermal cracks, heat-affected zone (HAZ), reduced material removal rate (MRR), poor surface finish, and compromised hole circularity. The utilization of different tool geometries provides the scope to cater these problems by altering gas film thickness and spark consistencies. The present article investigates the impact of different tool electrode’s geometry on machined glass hole’s characteristics using cognitive ECDM process that senses tool touch with the material. The different tool’s shapes like pointed, tapered, cylindrical and drill are utilized for investigation. The machining characteristics studied are MRR, MD, HT, thermal cracks, HAZ, SR, hole size, and hole circularity. Additionally, the effect of tungsten carbide (WC) and stainless steel material on MRR, MD, HT, SR, hole size, and TWR is studied.

The significance of uniformity and surface quality is highlighted by recent advancements in the fabrication of holes on glass materials, particularly for industrial applications of the electrochemical discharge drilling (ECDD) process. Nevertheless, the problem of inadequate electrolyte in the hydrodynamic area prevents the process of drilling which further results into a high hole tapering and poor depth. The present research explores the application of magnetic-assisted electrochemical discharge drilling (M-ECDD) to produce holes on a glass material using a closed-loop system of adaptive tool feed method, implemented to prevent the tool contacts with the glass material. The comparative analysis of the hole taperness (HT), machining depth (MD), surface roughness (SR), and material removal rate (MRR) is carried out with and without magnetic effect. Moreover, the effect of various input parameters on hole characteristics is studied. It is observed that the magnetic field regulates bubble formation and detachment, improving the ECDD process. Lorentz forces affect bubble behavior and film stability, resulting in magnetohydrodynamic (MHD) convection which forces the electrolyte to travel at higher depths, improving electrolyte circulation and discharge frequency. An improvement of 14.86

Regardless of the materials' intrinsic characteristics, electrochemical discharge drilling (ECDD) effectively micro-machines various materials. The present article optimizes the ultrasonic assisted rotary ECDD (UR-ECDD) process for maximizing the material removal rate (MRR), while minimizing the hole overcut (HOC) and circularity error (CE). The micro-holes are produced using a Taguchi's L16 array and multi-criteria optimization is carried out using grey relational based analysis (GRA). MRR, HOC and CE serve as a response parameter while tool vibration, tool feed rate, working material rotation, applied voltage and electrolyte concentration are control variables. UR-ECDD results in the improvement of 14.8% in MRR, 15.4% in HOC and 17.2% in CE when compared to the ECDD process. The optimized control variables based on GRA are derived as A4C3B4D1E4 (6 µm, 80 rpm, 0.9 mm/min, 35 V, 25 wt%). Tool vibration emerged as the most significant control variable. The GRG's predicted results at optimum conditions provide a satisfactory alignment with the experimental results. Machine learning-based algorithms are also used to predict the responses using Random Forest and Gradient Boost approaches. Comparative results indicated that the Random Forest predicts the responses with reduced error in comparison to the Gradient Boost method. The validation of the dataset exhibits a similar trend confirming the efficacy of prediction.

Metal matrix composites (MMC's) are now playing an indispensable role in today's manufacturing scenarios, in industries, where, the components require the high strength and reduced weight. These materials are crucial in applications involving, automobile manufacturing, aerospace engineering, and various industrial sectors. The study investigates the fabrication of hybrid nanocomposites of Aluminum 6063 with TiO2 and ZrO2 nanoparticles (NPs) as reinforcements, fabricated by stir casting. The experimental results demonstrated significant enhancements in impact energy absorption, Vickers hardness, and strength with raising the reinforcement content. Reduced wear rates (WR) and coefficient of friction (COF) are observed that attributed to improved dispersion and surface interactions induced by NPs. The study concludes that TiO2 and ZrO2 NPs synergistically enhanced the mechanical and tribological characteristics of Al6063, offering potential applications in industries requiring durable and high-performance materials. The findings indicate that the incorporation of NPs into Al6063-matrices is a viable method for enhancing tribomechanical characteristics. Applications that require materials with enhanced durability, resilience, and hardness, including aviation structures, automobile parts, and sports products, might discover this of considerable appeal.

Natural fibre reinforced polymer composites (N-FRP) have gained popularity in recent years as an alternative to regular polymer composites, owing to growing environmental concerns. Natural fibers are becoming increasingly popular due to their outstanding properties such as flexibility, strength, compatibility with living creatures, and impact resistance. A notable application of natural fibers is in the medical industry, with the goal of producing cost-effective, sustainable, and long-lasting products. Combining different fibers in the matrix can improve a material's mechanical characteristics in a hybrid method where one type of fibre can compensate for the deficiencies of another. Since the volume of fibers greatly affect the mechanical characteristics of hybrid composite materials, our present study is to investigate the effect of volume fraction of jute and sisal fibers on tensile strength of hybrid composite followed by machining using rotary electrochemical discharge-based machining (R-ECDM) process. The holes are fabricated at different electrolyte concentration and rotation of the tool. The hole overcut (HOC), Circularity error (CE) and surface roughness (SR) of the machined hole is analyzed to study the impact of input process parameter. ECDM applies the principle of thermal heating and chemical etching to remove the material and effectively applied for non-conductive brittle materials. The article's originality lies in the combined characterization study of hybridized N-FRP and its machining using RECDM. The tensile strength of composites improves as the volume of fibers increases due to the influence of individual fibre strengths. The proposed machining method is analyzed for machinability study of the N-FRP hybrid composites. The rotational effect improves the HOC, CE and surface roughness of the machined hole due to enhanced circulation of the electrolyte. The input parameters significantly affect the input parameters since all response parameters increases with the increase of electrolyte concentration and at higher level of tool rotation.

The current demand for composites reinforced with renewable fibers is greater than it has ever been. In comparison to glass fibers, natural fibers yield the advantages of lesser density and cost. Although comparable specific properties exist between glass and natural fibers, the latter shows lower strength. However, with the copper coating and chemical treatment of natural fibers, the strength of the composites can be increased nowadays. The current research investigation focuses on the life cycle assessment of the raw, chemically treated, and copper coated fiber reinforced bagasse and banana composites to compare the emissions on the environment of these samples to prove their applicability. The study includes all the processes, from the extraction of fibers to the formation of composites, i.e., from cradle to gate, and detailed inventory. The ReCiPe H midpoint method has been utilized in SimaPro software to quantify the emissions. The results indicate that the maximum global warming emission is due to the energy consumption used during the manufacturing of these composites. Electricity contribution for chemically treated and copper coated composites in global warming contribution is slightly greater than that of raw composites i.e., 73.275 % in C- BG/P, 73.06 % in Cu- BG/P, 73.65 % in C- BN/P and 74.28 % in Cu- BN/P which is comparatively higher than 63.8 % in R- BG/P and 64.97 % in R- BN/P. The next major contributions come from polylactic acid for all the three samples of bagasse fiber reinforced PLA composite and banana fiber reinforced PLA composite. The raw samples also show improved fiber strength compared to chemical and copper coated samples.

Friction stir spot welding (FSSW) is a prominent solid-state adhesion process. In the recent past, several investigations are performed for the property enhancement of FSSW welded joints especially on the mechanical and metallurgical characterization. In this work, an attempt has been made to analyze the effect of environmental conditions on the output quality characteristics of SiC reinforced Al6061-T6 welded joints, fabricated at optimal parametric setting. For this, welded joints are preserved at sub-zero temperature of −18 ± 2 °C for 90, 180, 270 and 360 days. Output quality characteristics in terms of tensile-shear and micro-hardness test in combination with microstructure analyses using SEM, EDS Mapping, and XRD analysis are emphasized. It is revealed that during sub-zero cooling, weld strength and micro-hardness of weldments increased over time. Additionally, a decrease in crystal size and increase in dislocation density are observed with increase in cooling period of weld joint, which eventually made suitable for extreme applications.

To machine "difficult-to-cut" materials including ceramics, glass, and silicon wafers, a hybrid and widely recognized process known as electrochemical discharge machining (ECDM) is used. It employs the working principle of electrochemical machining (ECM) and electric-discharge machining (EDM) processes to remove the material by combining chemical etching with thermal melting. The materials machined using ECDM exhibits enormous implementations in the field of MEMS and lab-on-chip. Different facets of the ECDM process have been researched in an effort to escalate its effectiveness ever since it was originally shown. The present chapter discusses the critical research potentials of the ECDM process that was documented in the past decades. Additionally, it covers the impact of several input process factors, including electrical, electrolyte, and tool electrode, on ECDM performance. A summarized report on ECDM hybridization, and variants are also given in a lucid manner. It also identifies future directions that might enhance the ECDM process's overall machining performance. It is concluded that with the help of gas film dynamics controlled by variables such as electrolyte characteristics and tool motions, ECDM can machine non-conductive materials with precision. Pulsed voltage, suggested electrolytes (NaOH, KOH), and regulated tool properties (material, shape, and rotation) are important factors. Spherical tool electrodes help minimize overcut and taper comparative to other tools while machining depth and geometrical accuracies can be further improved by implementing hybridization such as magnetic assistance & ultrasonic assistance.

Natural fiber composites have gained popularity among researchers due to their recyclability, biodegradability and potential to replace synthetic composites. Hence, to enhance the strength and stiffness of biocomposites all possible combinations of fibers were studied through hybridization. In the present investigation banana fibers were hybridised with bio-waste bagasse/PLA biocomposites using extrusion-injection moulding process. The overall fiber concentration for the study was fixed at 20%, and PLA as 80%. While the ratio of fiber composition of bagasse/banana fibers for the biocomposites were considered as 100/0, 75/25, 50/50, 25/75 and 0/100. The thermal, mechanical and water absorption properties of fabricated hybrid biocomposites were studied. Thermal properties in terms of thermogravimetric analysis were examined and thermal stability of biocomposites improved after hybridization. Moreover, tensile, and flexural strength of hybrid biocomposites were improved by 21% and 14.4%. Similarly, tensile, and flexural modulus were increased by 47.6% and 16%, respectively. The fiber orientation and dispersion within the developed hybrid biocomposites were also examined and fiber twisting, breakage and cluster formation were also observed. Scanning electron microscopy (SEM) invested fiber pull-outs, fiber breakage, matrix breakage and fiber-matrix adhesion throughout the surface of biocomposites. On the other hand, water absorption properties of hybrid biocomposites were conducted and water absorption percentage for twelve days were concluded in this study.