Advanced Materials Research Vol. 1188

Abstract: Al₂₅Ni₂₅W₂₅Cr₂₀V₅ refractory high entropy alloy (RHEAs) was synthesised by mechanical alloying (MA) and its characterization study and mechanical behaviour of this prepared refractory high entropy alloy was investigated in this research work. After 18 hr of mechanical alloying, fine grained microstructure was obtained and homogeneous distribution of all metal elements was achieved. Crystallite size, lattice strain and phase analysis of prepared RHEAs powders were calculated through X-ray diffraction (XRD) techniques. Morphological study of prepared RHEAs powders was investigated through scanning electron microscopy (SEM). Aluminium, Nickel, Tungsten, Chromium and vanadium elements presented in the prepared RHEAs were identified through Energy dispersive spectrum analysis (EDAX). After milling, powders were compacted and sintered at two temperatures such as 600°C and 800°C. Density, porosity and Vickers micro hardness measurements were taken after sintered at 600°C and 800°C. The results indicate that the sintering environment and conditions will affect the mechanical properties of developed Al₂₅Ni₂₅W₂₅Cr₂₀V₅ refractory high entropy alloy.

Abstract: In the previous many years, several attempts have been made to enhance the effectiveness of the Spark erosion machining process. This review clearly mentioned all the work outputs of Vibration Assisted Electric Discharge Machining at a glance. One of these non-traditional machining techniques, called electric discharge machining (EDM), produces higher surface finishes, high levels of precision, and machinability. Ultrasonic vibrations are used in many industrial processes, such as material removal operations for form generation on material surfaces. Lately, there has been an increasing trend toward using ultrasonic vibration to enhance process performance. Ultrasonic vibration finds noteworthy application in industrial processes such as spark erosion machining, where vibration is enhanced by using ultrasonic waves as a medium. The electrode's ultrasonic vibration modifies the discharge gap and improves the chip removal capability, making it a very effective technique for raising EDM efficiency. An overview of the literature on the application of ultrasonic vibrations in electric discharge machining is presented in this article. Review work has been done on how ultrasonic vibrations can be applied, their ability to affect performance metrics, how to predict and optimise processes, and how to use them with advanced materials that can be difficult to cut. Future requirements for research have been highlighted to increase the ability and potential for the technique of electric discharge machining based on an evaluation of the present state of ultrasonic-assisted electric discharge machining.

Abstract: In this research work, Ni rich superelastic Nickel-Titanium(NiTinol) alloy rods were joined using a fully automated direct-driven rotary friction welding machine at 1900 rpm. Samples were subjected to heat treatment after the removal of flash bead. Corrosion behavior of the NiTinol samples were carried out using weight loss method and Potentiodynamic Polarization (PDP) technique using 3.5% NaCl and 1N HCl solution in interval of 12h, 24h, 36h, and 48h at different temperature conditions such as 25°C, 35°C, 45°C, and 55°C respectively. Research has been carried out to find the corrosion characteristics for both annealed and cryogenically treated samples. Research findings revealed that, in weight loss method the impact of corrosion has no effect in the welded zone. In PDP method, the corrosion rate is found to be less and insignificant compared to any other alloys. Hence, the material proved as anti-corrosive in nature. This fact is due to the formation of Titanium oxides (TiO₂) and Titanium nitrides passive layers which hinders the rate of corrosion. However, more corrosion resistance was seen in cryogenically treated welded samples compared to the other samples.

Abstract: This study aims to optimize the corrosion resistance and mechanical properties of angle steel used in transmission towers. It systematically explores the influence of C, Mn, Nb, V, Ti strengthening elements and Cr, Ni corrosion resistant elements on the comprehensive performance of 420 MPa weathering steel. Seven sets of experimental steels were prepared using vacuum melting combined with controlled rolling process. The mechanism of alloy elements on microstructure evolution, mechanical properties, and corrosion behavior was studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), and electrochemical testing. The results showed that the experimental steels exhibited a dual phase structure of ferrite and pearlite, and the strength was significantly improved by the precipitation strengthening of V element through carbonitride (yield strength reached 420-441.5 MPa). The synergistic regulation of C-Mn can effectively optimize the carbon equivalent to balance weldability. In the cyclic infiltration test simulating acid rain environment, the alloy ratio of Cr≥0.45% and Ni≥0.15% can reduce the relative corrosion rate to below 50% of conventional Q420 angle steel. Microscopic analysis reveals that the content of α-FeOOH in the dense rust layer formed on the surface of weathering steel is over 95%, significantly higher than the 49.4% of conventional steel. This stable rust layer effectively improves the corrosion resistance by suppressing the anodic dissolution process. This study provides theoretical basis and process parameters for the composition design of weathering angle steel for transmission towers.

Abstract: For conducting a comprehensive analysis of phenols and their diversity from Phyllostachys glauca McClure leaves (PML) and Pleioblastus argenteostriatus leaves (PAL), this study employed widely targeted metabolomics. The results of widely targeted metabolomics analysis indicate flavonoids and phenolic acids totally accounted for 85.26% are the predominant phenols in bamboo leaves measured. Multivariate statistical methods reveal 187 flavonoids, 97 phenolic acids, and 28 lignans are significantly upregulated in PAL. Consequently, PAL demonstrates a greater potential for the utilization of phenols. Additionally, twenty differential phenols were identified that can effectively distinguish PML and PAL. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis reveals the biosynthetic pathways of the annotated differential phenols. This research offers a reference for the development and use of phenols in two bamboo leaves, potentially enhancing their application in the industries of food, healthcare product, drug etc. It is also a comprehensive report for the phenols in bamboo leaves.

Abstract: Paracetamol is a popular analgesic and antipyretic medication. Paracetamol, on the other hand, is hepatotoxic to the body because it interferes with the peroxidase enzyme by trapping radicals that induce the cyclooxygenase reaction; thus, it should not be administered to children under the age of three or to adults for more than ten days. This necessitates the development of safer and more effective alternatives to paracetamol to address the demand for analgesic and antipyretic medications in children and adults. The substance 1,3-bis(p-hydroxyphenyl)urea was discovered to have double the potency of paracetamol as an analgesic and antipyretic, and less hepatotoxic effects than paracetamol; hence, it has the potential to decrease domestic demand for paracetamol. The objective of this study was to optimize the synthesis of 1,3-bis(p-hydroxyphenyl)urea by investigating the effects of temperature and the molar ratio of para-aminophenol to urea on the yield and quality of the product. The synthesis was conducted in two stages: an initial pre-reflux stage lasting 30 minutes, followed by a reflux stage of 60 minutes. Experimental results demonstrated that the optimal synthesis conditions were achieved at a para-aminophenol to urea molar ratio of 2:5, yielding a 66.67% product.

Abstract: The exponential growth of electronic waste (e-waste), particularly from discarded SIM cards, has raised significant environmental concerns due to the presence of valuable metals such as copper (Cu). This study investigates the recovery of copper from SIM card waste through hydrometallurgical methods, focusing on the effects of pH and reaction time on the precipitation of Cu(OH)₂. The SIM card waste was leached using nitric acid, followed by copper precipitation through the addition of sodium hydroxide at various pH levels (11, 12, 13, and 14). The solid precipitates were analyzed using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) to determine their morphology and functional group composition. The results indicate that optimal conditions for copper precipitation were achieved at a pH of 11, yielding the highest purity and the lowest Cu concentration in the filtrate. SEM analysis revealed that Cu(OH)₂ particles formed distinct crystal structures that varied with pH, while FTIR confirmed the presence of Cu-OH functional groups, indicating successful copper recovery. This study highlights the potential of hydrometallurgical processes for environmentally friendly copper recovery from e-waste, providing insights into optimizing industrial-scale applications.

Abstract: Rapid population increase coupled with industrialization has led to rise in global energy demand leading to skyrocketing of energy prices. Diversification in energy resources is essential to reduce overdependence on certain resources. Agricultural wastes remain a promising energy resource to be exploited. Laboratory experimental analysis is time consuming and costly. This fueled the adoption of modelling as an alternative to laboratory analysis. Different models such as computational fluid dynamics (CFD), artificial neural network (ANN), and ANFIS fuzzy logic have been used by various researchers. Buckingham pie theorem together with MATLAB was used in this research to evaluate the properties and combustion characteristics of assorted agricultural wastes. The properties modelled were; porosity, density, shatter resistance, higher heating values, burnout time, burning rate, ignition time and efficiency. The factors that affect each of the properties negatively and positively were determined from the models. The significance of each property and characteristics were articulated. The limitations and assumptions of the models were also highlighted. It is recommended that further research incorporating artificial intelligence in the models needs to be exploited aid in reduction of experimental analysis costs and time. Other agricultural wastes which have not been characterized for need to exploited. This will further reduce overdependence on conventional resources such as fossil fuels which are not only getting depleted at an alarming rate but also led to environmental degradation.

Abstract: The effective recycling of industrial waste is a globally significant issue. In this study, a geopolymer binder was synthesized using an alkaline activator derived from brown coal gangue and blast furnace slag, along with silica fume as an industrial waste material. Also, the properties of these geopolymer binders are examined using them as a briquette binder. At temperatures above 700°C, roasted brown coal gangue is more active than the initial state. The optimum dosage of alkaline activator is 10M NaOH, silica fume/NaOH ratio of 3, specific gravity of 1.42, and the addition of binder of 6%. The main polymerization products of the alkali activated brown coal gangue geopolymer samples are N-A-S-H gel and amorphous aluminosilicate gel, while the main polymerization products of the alkali activated brown coal gangue -blast furnace slag geopolymer samples are N-A-S-H gel, C-(A)-S-H gel and amorphous aluminosilicate gel. Blast furnace slag is added during the preparation of briquette binder by brown coal gangue geopolymer, which increase the mechanical strength of the geopolymer binder and the optimum dosage is 30%. This study demonstrates a high-value and sustainable pathway for co-utilizing multiple industrial by-products.