Papers by Keyword: Characterization

Abstract: The processing of metallic materials alone has a huge impact on resource utilization, emission, and waste generation. With the emergent ecological concerns, there is a solid thrust towards sustainable materials development. Sustainable metal matrix composites are designed to minimize environmental impacts by reducing resource consumption and energy usage and curbing waste generation. Now a days, the automotive sector is making significant strides towards a more ecological product chain by adopting sustainable reinforcements such as basalt fibres, red mud reinforcements, fly ash, cenosphere particles etc. into matrix material which significantly influence the mechanical properties. With this perspective, the present work is aimed to investigate the hardness, tensile, flexural, impact and wear characteristics of 7075 reinforced with different combinations of B4C, egg shell particles along with fly ash. The results revealed that the best mechanical and wear are measured at 3 % boron carbide, 3 % Egg shell powder and 2 % fly ash reinforced AA-7075 composite among the other developed composites. The results thus suggested that the incorporation of sustainable reinforcements along with ceramic reinforcements offer enhanced material characteristics, cost savings and environmental advantages.

Abstract: The need to obtain a uniformly distributed reinforced particulate on AA6063 aluminium alloy for improved mechanical, corrosion and structural properties has necessitated this study. A well synthesised biocompactable particulate of rice hulls/periwinkle shells under varying matrix of 85Al-9.0RHA-6.0PSA, 85Al-7.5RHA-7.5PSA, and 85Al-6.0RHA-9.0PSA was developed and compared with the control for manufacturing application. The microstructural evolution was observed using SEM/EDS quantification. The intermetallic assessment was done using X-ray Diffractometer (XRD). The diameter of indentation was used to measured the microhardness respnses. The corrosion rate and polarization resistance was examined using Liner polarization resistance technique and open circult potential route under simulated 3.65% NaCl. From the results, 85Al-9RHA-6PSA composite sample exhibited slightly lower Cr, lower j_corr, and higher Pr of 0.3562 mm/year, 3.066E-05 A/cm² and 139.33 Ω, respectively against the control sample. An indication of a significant passive characteristics. The 85Al-9RHA-6PSA composite sample also exhibited few dimples, shrinkage cavities and micropores. With composite alloys, good crystalline were observed inform of Al₁₆Co₇Zr₆Al₁₅Co₄ and Al_0.52Co_0.48Al₁₆Co₇Zr_6. The hardness properties improvement from 54.8 to 63.8% provides a significant effect of solid strengthening performance of the hulls/shells as a biocompactability infringement of structural alloy.

Abstract: Copper sulphide (Cu₂S) is an indirect gap p-type semiconductor belonging to I-VI group. The wet chemical route was used to synthesize manganese (Mn) doped copper sulphide nanoparticles with a decrease in particle size by increasing the concentration of manganese element. These nanoparticles were analyzed by using the various characterization techniques like ultraviolet-visible (UV) absorption spectroscopy, photoluminescence (PL) spectroscopy and transmission electron microscopy (TEM). The dip coating method was used to prepare Mn doped Cu₂S thin films on fluorine doped tin oxide (FTO) glass slides with varying the dip time. These thin films were heat treated in air atmosphere at 420°C for 20 minutes and investigated by using the various analysis techniques like scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive analysis by X-rays (EDAX) and mapping. The detailed explanation of obtained experimental results is discussed in this paper.

Abstract: Additive Manufacturing technologies revolutionize the production of 3D components by selectively depositing material layers, facilitating intricate geometries and cavities with minimal material waste. Among these techniques, Plasma Metal Deposition (PMD) stands out as a powder-based method offering promising applications, particularly in the aerospace sector.In this study, five specimens manufactured via PMD have been investigated, employing a base material of Grade 2 titanium and a welding material comprising a powder blend of grade 1 titanium and 30% B₄C particles. The incorporation of boron carbide aims to further augment the already commendable properties of titanium, catering to the stringent requirements of the aerospace industry.Attention is directed towards key manufacturing parameters such as the transferred arc and torch travel speed, while maintaining fixed parameters including pilot arc, current, and torch-substrate height. The primary objective of this research is to comprehensively explore the PMD technique, scrutinizing potential thermodynamic reactions during the welding process between titanium and boron carbide. Concurrently, thorough characterization of the specimens will be conducted to elucidate their properties.This project seeks to optimize the PMD manufacturing process and enhance the performance characteristics of the produced parts, thereby addressing critical needs in the aerospace sector. By unravelling the intricacies of thermodynamic interactions and material properties, we aim to pave the way for advancements in additive manufacturing methodologies and the production of high-performance titanium components for aerospace applications

Abstract: The development of non-enzymatic glucose biosensor has been the concern of many researchers mainly because enzymes based sensor despite having excellent sensitivity and selectivity, has the limitations such as poor stability, complicated enzyme immobilization, critical operating conditions such as optimum temperature and reproducibility. This study developed a cheap biocompatible non-enzymatic glucose biosensor based on silver nanoparticle (AgNPs) stabilized with sodium tripolyphosphate (NaTPP) cross-linked chitosan. Direct electron transfer and electro-catalytic activity of the AgNPs modified glassy carbon electrode (AgNPGCE) was investigated using potentiometric and amperometric techniques. AgNPs was prepared and characterized by Fourier transform Infra-red spectroscopy (FTIR), X-ray diffractometry (XRD) and Scanning electron microscopy (SEM). The crystalline size of the AgNPs was revealed with XRD. However, the SEM micrograph of AgNPs revealed the spherical shape with a non-uniform granular shape attributed to bio-mediated ionic gelation process. The FTIR spectra of AgNPs shown peaks at 1054 – 1645 cm^-1 suggesting the presence of phosphonate linkages between ammonium, -NH₃⁺ of chitosan and -PO₃^2- moieties of NaTPP during cross linking process. Electro-catalytic oxidation of glucose at the AgNPGCE surface and the mechanism involved in glucose oxidation was revealed via cyclic voltammetry. The AgNPGCE showed a better electrochemical response towards glucose. This glucose sensor showed high sensitivity at +0.54 V. A low detection limit of 1.22 µM (the confident level κ = 3), and wide linear range of 2 to 24 µM with a correlation coefficient of 0.9987 were obtained. The calculated parameters revealed that AgNPGCE had shown better overall electrochemical performance and response than enzymatic biosensor.

Abstract: The application of membrane technology in the separation process has led to the technology's present rapid development. Nylon 6.6 polyamide membrane has hydrophilic properties and has advantages such as low fouling tendency and resistance to high temperatures. This research aims to determine the effect of pectin on the characteristics of nylon 6.6 membranes. In this study, the membrane was made from nylon 6.6 using the phase inversion technique. Modification was carried out by adding pectin at variations of 0, 0.25, 0.5, and 0.75% by weight. The IR structure characterization results of the nylon6.6-pectin membrane show the same peak for the-NH group and the OH, C-H, amide I, amide II, amide III, CH₂, and C-C groups. Membrane contact angle measurements P0, P0.25, P0.5, and P0.75 were 59.37°, 67.70°, 63.48°, and 58.00° respectively, indicating hydrophilic properties. Meanwhile, the degree of swelling after the membrane was soaked in distilled water for 24 hours showed values of 55.32%, 44.44%, 60.38%, and 63.16% for membranes P0, P0.25, P0.5, and P0.75. The P0.75 membrane has the lowest contact angle which is increasingly hydrophilic and the highest swelling value which indicates the highest absorption level compared to other variations.

Abstract: The filtration of hexavalent chromium (Cr(VI)) presents a significant challenge in water treatment due to its toxicity and environmental impact. This study is oriented towards the development of a zeolite-based membrane for the removal of Cr(VI) ions. Flat supports are made from clay with a particle size between 160 and 250 µm and then characterized by different techniques namely FTIR, XRD, and point of zero charge (pHpzc). The clay support creates a porous structure, ideal for adsorbing Cr(VI) ions, while the LTA-type zeolite membrane offers selective permeability, through its narrow pore size, tuning the volume down on Cr(VI). Filtration experiments were conducted under a pressure of 1.0 bar, initial Cr(VI) concentration of 10^-4 M and pH = 5.4 to evaluate the efficiency and performance of the composite membrane. Results demonstrate significant reduction in Cr(VI) concentration, with a 30% and 50% retention on the clay support and the LTA-zeolite membrane respectively. The proposed methodology has the potential to create advanced water treatment systems that can effectively remove Cr(VI) pollutants from aqueous solutions, thereby challenging important environmental issues.

Abstract: This study investigates the corrosion inhibition performance of Anthocleista grandiflora leaf (AGL) extract on carbon steel in seawater, considering the effects of temperature, immersion time, and inhibitor concentration. Predictive modeling, adsorption behavior, and the kinetics and thermodynamics of the inhibition process were examined. The weight loss technique,characterization techniques combined with response surface methodology (RSM), revealed that the AGL extract follows the Langmuir adsorption model, exhibiting physical adsorption with ΔG values between −16.24 to −15.49kJ/mol, indicating spontaneous and endothermic inhibition. The thermodynamic parameters entropy (−198.87 to −52.58 J/mol), enthalpy (20.42 to 53.42 kJ/mol), and activation energy (13.68 to 56.32 kJ/mol further support this. The corrosion reaction follows first-order kinetics, with the half-life decreasing as the rate constant and extract concentration increase.The SEM images revealed that the AGL extract formed a protective surface layer on the mild steel, effectively preventing pitting. This protective effect became more pronounced as the concentration of the extract increased. RSM optimization identified optimal conditions for maximum inhibition efficiency (98.70%) and corrosion rate (0.058 mm/y) at 800 ppm, 303 K, and 45 days, with a prediction accuracy of 95%, making it suitable for application in the oil and gas industry.

Abstract: Aluminum Bronze bushing sleeves or sleeve bearings are used in the various parts of vehicles like camshaft bushing, suspensions, shock absorber, gears and strut bushes for anti-wear, anti-friction and for bearings high tensile loads. This research presents a comprehensive study on the development of Aluminum bronze bushing sleeves using horizontal centrifugal casting method. The effect of centrifugal casting parameters i.e. molds rotation speed, melt temperature, alloy composition and heat treatment optimizes mechanical properties and also microstructure of developed bushing sleeves. These bushing sleeves with desired composition have been developed by using induction furnace to reduce its import and to save foreign exchange. Different samples were casted by using horizontal centrifugal casting machine by varying parameters like rotation speed of mold and pouring temperature of melt in order to get good quality bushing sleeve. The addition of trace elements like Manganese, Iron, nickel and Zinc optimize the mechanical properties of bushing sleeves for particular application in elevating and depressing mechanism of heavy vehicles. The developed material was characterized by using different characterization techniques like Spectroscopy (OES), wet analysis, mechanical testing, optical microscope and Scanning Electron Microscope (SEM).

Abstract: The purpose of the work is to quantify and predict the influence of inhomogeneity of local properties on the overall behavior of the selected casting aluminum wheel and knuckle in different loading cases. Smooth and notched tensile specimens and torsion specimens are extracted from different positions in the wheel and knuckle and tested. The dependences of the flow stress, the fracture strain, and the S-N curve on position for specimen extraction are evaluated. Metallographic investigations are performed to reveal the relations between microstructure/microdefects and the mentioned properties. A damage model based on a triaxiality-dependent fracture strain is calibrated and used to simulate the specimens and component tests. The simulations of static wheel tests and knuckle fatigue tests are performed with position-dependent material parameters. The prediction of the component tests is compared with the experimental results.