20 research outputs found
Identification and recovery of rare earth elements from electronic waste: Material characterization and recovery strategies
No full textThe sustained growth of the electronic and electrical industries necessitates not only efficient energy utilization throughout all manufacturing stages but also the recycling of end-of-life electric and electronic components. However, rapid advancements, miniaturization, and added value have led to a significant accumulation of e-waste, posing environmental concerns. Rare Earth Elements (REE) are considered critical raw materials that face a risk of global supply shortage due to their highly desirable performance-enhancing properties such as corrosion resistance. This study focuses on identification and exploring the recycling possibilities of different types of electronic waste for Rare Earth Materials. The electronic waste is first disassembled and categorized, after which material characterization techniques are employed to identify Rare Earth Elements (REEs). X-Ray Diffraction, X-ray fluorescence spectroscopy, Scanning Electron Microscopy, and Energy-dispersive X-ray spectroscopy are utilized for this identification. Subsequently, an in-depth review of existing literature is conducted to ascertain the most appropriate method for recovering these REEs. Neodymium and Dysprosium are among the REEs identified in the electronic waste samples.</p
EBSD characterization of Ag<sub>3</sub>Sn phase transformation in Sn–Ag lead-free solder alloys:a comparative study before and after heat treatment
No full textThe phase transformation and microstructural evolution of Sn–Ag solder alloys under heat treatment, with a focus on the Ag3Sn phase, were investigated to address the need for reliable lead-free solder alternatives in electronic packaging. Initially, the solder alloy exhibited a fine eutectic structure with well-dispersed Ag3Sn particles and a polycrystalline grain structure devoid of any strong crystallographic texture. Following heat treatment, significant microstructural changes were observed, including the coarsening of the Ag3Sn phase and the development of a preferred grain orientation, suggesting recrystallization and grain growth. XRD analysis revealed a decrease in the intensity of the Sn phase peaks and an increase in the coarseness of the Ag3Sn peaks post-heat treatment, indicating phase evolution and redistribution of silver within the alloy. The EBSD results supported the SEM findings, showing elongation and growth of grains and a shift in texture. These changes imply that heat treatment can significantly alter the mechanical properties of Sn–Ag solders, particularly affecting creep resistance and hardness due to the evolution of anisotropic mechanical properties. The study provides essential insights into the selection and optimization of solder materials for high-reliability applications in the electronics industry
Characterization Studies on Graphene-Aluminium Nano Composites for Aerospace Launch Vehicle External Fuel Tank Structural Application
No full textFrom the aspect of exploring the alternative lightweight composite material for the aerospace launch vehicle external fuel tank structural components, the current research work studies three different grades of Aluminium alloy reinforced with varying graphene weight percentages that are processed through powder metallurgy (P/M) route. The prepared green compacts composite ingots are subjected to microwave processing (Sintering), hot extruded, and solution treated (T6). The developed Nano-graphene reinforced composite is studied further for the strength−microstructural integrity. The nature of the graphene reinforcement and its chemical existence within the composite is further studied, and it is found that hot extruded solution treated (HEST) composite exhibited low levels of carbide (Al4C3) formations, as composites processed by microwaves. Further, the samples of different grades reinforced with varying graphene percentages are subjected to mechanical characterisation tests such as the tensile test and hardness. It is found that 2 wt% graphene reinforced composites exhibited enhanced yield strength and ultimate tensile strength. Microstructural studies and fracture morphology are studied, and it is proven that composite processed via the microwave method has exhibited good ductile behaviour and promising failure mechanisms at higher load levels
Microstructural and mechanical behaviours of Y-TZP prepared via slip-casting and fused deposition modelling (FDM)
No full textThis paper reports the microstructural characteristics and mechanical properties of yttria-stabilized zirconia prepared via fused deposition modelling and slip casting. X-Ray Diffraction peaks indicated that yttria-stabilized zirconia crystallized in tetragonal structure for both slip casted(SC) and fused deposition modelled(FDM) samples. Further, scanning electron microscopy of slip casted sample showcased closely packed structure with fine grains and an average grain size of ∼65 nm whilst fused deposition modelled samples showcased non-homogeneous pores with ∼20 nm grain size. Average relative density of slip casted samples was ∼99.4 % while that of fused deposition modelled sample exhibited ∼96.2 %. The Vickers Hardness of slip casted (∼15.26 ± 0.4 GPa) was ∼10 % higher than the fused deposition modelled samples (∼13.79 ± 0.3 GPa). Likewise, indentation fracture toughness of slip casted (5.78 ± 0.5 MPa m1/2) was 14 % higher than fused deposition modelled samples which could have been due to the change in grain size as well as porosity of the ceramics. Compressive strength of the fused deposition modelled samples was 32 % less than slip casted samples (∼510 ± 10 MPa) due to its non-homogenous pores which led to weakening van der Waals force of attraction
An Experimental Investigation into the Enhancement of Surface Quality of Inconel 718 Through Axial Ultrasonic Vibration-Assisted Grinding in Dry and MQL Environments
No full textUltrasonic vibration-assisted grinding (UVAG) has proven to be beneficial for grinding difficult-to-machine materials. This work attempts to enhance the grinding performance of Inconel 718 through a comprehensive study of UVAG characteristics. Grinding experiments were performed in both dry and Minimum Quantity Lubrication (MQL) environments, and assessment of the grinding forces, specific energy, residual stress, and surface topography was done. A substantial reduction of both surface roughness and grinding force components was observed in UVAG compared to conventional grinding (CG). Utilizing UVAG with MQL at the maximum vibration amplitude led to a 64% reduction in tangential grinding force and a 51% decrease in roughness parameter, Ra, when compared to CG conducted in a dry environment. The high-frequency indentations of the abrasives in UVAG generated compressive residual stresses on the ground surface. Surface parameters pointed to uniform texture and SEM images showed widening of abrasive grain tracks on the workpiece surface during UVAG. The utilization of UVAG under MQL produced a synergistic impact and resulted in the lowest grinding forces, specific energy, and optimal surface quality among all the grinding conditions investigated. Overall analysis of the results indicated that the axial configuration of the vibration set-up is favorable for UVAG, and the high-frequency periodic separation-cutting characteristic of the process improves lubricating efficiency and grinding performance
Effect of T6 and T8 Ageing on the Mechanical and Microstructural Properties of Graphene-Reinforced AA2219 Composites for Hydrogen Storage Tank Inner Liner Applications
No full textThis study examines the mechanical and microstructural properties of graphene-reinforced AA2219 composites developed for hydrogen storage tank inner liner applications. A novel processing route combining high-energy ball milling, ultrasonic-assisted stir casting, and squeeze casting was used to achieve homogeneous dispersion of 0.5 wt.% graphene nanoplatelets and minimise agglomeration. The composites were subjected to T6 and T8 ageing treatments to optimize their properties. Microstructural analysis revealed refined grains, uniform Al2Cu precipitate distribution, and stable graphene retention. Mechanical testing showed that the as-cast composite exhibited a UTS of 308.6 MPa with 13.68% elongation. After T6 treatment, the UTS increased to 353.6 MPa with an elongation of 11.24%. T8 treatment further improved the UTS to 371.5 MPa, with an elongation of 8.54%. Hardness improved by 46%, from 89.6 HV (as-cast) to 131.3 HV (T8). Fractography analysis indicated a shift from brittle to ductile fracture modes after heat treatment. The purpose of this work is to develop lightweight, high-strength composites for hydrogen storage applications. The novelty of this study lies in the integrated processing approach, which ensures uniform graphene dispersion and superior mechanical performance. The results demonstrate the suitability of these composites for advanced aerospace propulsion systems
Behavioral Economics of religion and worship
No full text
The author has attempt to provide a
seminal view on rationalizing the way in which individual conceptualize the
worship and trace onto how the behavioral economic theory explain the
theoretical implication behind morality, religion, culture , habit, and suggest
how the existence of incomplete information in the religious market determine
the value of it.
Everything
is a product in Economics. The ways in which the consumer use it and achieve
the utility, satisfaction determine the market of it. In this perspective god
and the activities related to self-realization is also considered as one of the
product which has to be realized through specific methods of explained in Vedas
and Upanishads. People at present generation are interested to find out what is
the meaning of god and where it is exist. If god exists why and how it favors
somebody to become milliners and billionaires and left aside the others on the
roadside even without enough food for survival. What is the uniform meaning of
god and how it can be realized through subjective, experimental and scientific
ways? How and why some consumers follow a particular religion while other
consumers are prefers to the next best. What makes individual consumers
satisfied in worshiping a particular god and how it works to realize one’s self
and relation it has with the morality? How the science of behavioral Economics
interprets the act of search for godness by some consumers using some specific
religious while some others not even bothered about it. What are the core
implications of all the religions in the practice of understanding god or self
realization?
There
are very limited attempts are available in the academic literature highlighting
the Economics implications of search for goddess and self
realization and the Economics morality behind the various methods
adopted by numerous religions in realization of self, omniscience. It is in
this context this conceptual paper is attempted to fill this gap in research.
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Effect of Recast Layer on the Strength Properties of the Spark Electric Discharge Machined Aluminium Alloy Composites
No full textThe objectives of this research work are to determine the influence of effect of spark electric discharge machine on the recast layer and indeed the strength properties of the AA 6061-Graphene composites. The green compacts were subjected to microwave sintering at 550 °C for 30 minutes. The sintered samples are then hot extruded at 300 °C to flat plates and air cooled later. The extruded samples are subjected to mechanical characterization for density, hardness and tensile strength. Further, spark EDM process is used to machine the extruded samples. The SEDM processed samples with the aluminium alloys 6061-Gr composites compared with the as extruded condition. The hardness studies on the samples are carried out using Rockwell hardness testing machine with B scale as per standards, Tensile strength studies are carried out in Instron Universal Testing Machine with a standard strain rate of 0.75 mm/min. Recast layer of the SEDM samples is studied using HR-SEM and the thickness of the recast layer is recorded. The influence of the recast layer thickness on the tensile strength the extruded composite is studied. The surface roughness and material removal rate (MRR) of the extruded composites after the SEDM process also studied in correlation with the strength properties.</jats:p
Small-angle neutron scattering analysis in Sn-Ag Lead-free solder alloys:A focus on the Ag<sub>3</sub>Sn intermetallic phase
No full textThis study addresses the critical need for lead-free solder alternatives in electronic manufacturing by investigating the microstructural characteristics of Sn-Ag solder alloys, focusing on the Ag3Sn intermetallic phase. Utilizing Small-Angle Neutron Scattering (SANS), the study explored the phase interface and grain structure within Sn-Ag alloy to identify attributes that influence mechanical stability and performance. The research was structured around a comprehensive SANS analysis, complemented by Electron Backscatter Diffraction (EBSD) to expose the morphology and orientation of crystalline phases within the material. The investigation revealed distinct scattering patterns indicative of a multi-phase structure with a homogeneous distribution of fine Ag3Sn precipitates within a β-Sn matrix. EBSD data confirmed these findings, showing a wide range of grain sizes and a random orientation distribution that matches theoretical models for polycrystalline materials. Notably, the SANS data uncovered a specific size distribution of the Ag3Sn phase, which was characterized by a sharp interface contrast against the β-Sn matrix, pivotal for understanding the solder's mechanical properties. Interpretation of the SANS and EBSD data sets suggests that the Sn-Ag alloy's performance is significantly influenced by the dispersion and morphology of the Ag3Sn phase. The presence of nanoscale Ag3Sn structures, exhibiting a needle-like surface, implies a material optimized for mechanical reinforcement, which is essential for robust electronic connections. The integrated approach offers a novel perspective on the nano structural arrangement of lead-free solders, contributing to the advancement of safer, more reliable electronic materials. The findings have significant implications for the development of next-generation electronic components, reinforcing the transition to environmentally benign manufacturing processes.</p
Investigation on CFRP 3D printing build parameters and their effect on topologically optimised complex models
No full textThis research investigates the effects of building parameters for 3D printing Carbon Fibre Reinforced Polymers (CFRP) and their effect on topologically optimised complex models. The work is conducted by initially developing a DOE varying two parameters in 3D printing namely (i) infill ratio and (ii) infill pattern. Then based on standards ASTM D638 and ISO178, for tensile and flexural tests, specimens are 3D printed and tested for the material Nylon with CFRP (Onyx). From the results it can be observed that (i) specimen with an infill ratio of 85% (constant triangular infill pattern) was found to have the best performance recording a length extension of approximately 5.6 mm under a tensile load of 700 N (ii) in case of infill pattern, triangular shape (constant infill ratio of 37%) recorded the highest the length extension of 7.3 mm under tensile load of 650 N. (iii) 85% infill ratio (constant triangular infill pattern) recorded a bending deflection of approximately 6 mm under a compressive load of 250 N and (iv) the gyroid infill pattern (constant infill ratio of 37%) provided the highest flexural strength with an approximate extension of 5.6 mm under a compressive load of 350 N. After the experimental study and analysing the best parameters, a static analysis and topology optimisation for the 3D printed material (Nylon with CFRP(Onyx)) has been performed on an industrial part for its design validation. Based on the analysis, the original part is redesigned, and again a static analysis simulation is performed to determine the effects of the optimisation process for the same material comparing with 316L-Stainless Steel (SS). Finally, the redesigned model is manufactured with the best 3D printing parameters and validated against the original operating conditions. This study will help industries to use these 3D printing parameters where a metal-based components needs to be replaced with CFRP
