Powder metallurgy is a versatile manufacturing process known for its ability to produce complex-shaped components with tailored properties, making it invaluable across multiple industries. This study investigates and compares the compaction behaviour, mechanical properties, and microstructure of pure aluminium powder using both conventional strain rate compaction, i.e. radial mechanical pressing (RMP) and high strain rate compaction, i.e. electromagnetic compaction (EMC) methods. The RMP process employs a hydraulic press to compact the powder conventionally. In contrast, in the EMC process, a rapid and intense magnetic field is generated through a solenoid coil, resulting in high-strain-rate compaction. Both process involves radial compaction of powder to generate a cylindrical specimen. After compaction, the samples are sintered, prepared, and tested. The testing includes hardness tests and microstructural analysis by using optical microscopy as well as scanning electron microscopy (SEM) imaging. Results are compared between the RMP and the EMC processes. This research aims to fill a critical gap in the field by enabling a direct comparison of radial compaction of powder at conventional and high strain rates, providing valuable insights into the influence of strain rate on the properties of powder compacted samples.

To achieve a smooth surface finish and minimum tolerances on cylindrical objects, cylindrical grinding is a popular practical method in industry. In this process, material is removed from the workpiece surface as small chips, and after this process, post-processing is not required. A grinding wheel is used in this process. Currently, there are various grinding processes, such as creep-feed grinding, surface grinding, centerless grinding, internal grinding, and cylindrical grinding. This process is used to grind external cylindrical parts such as spindles, connecting rods, cam shafts, engine shafts, axles, propeller shafts, etc. A cylindrical grinding machine is used to achieve a high machining rate and a high surface finish. The effect of the process parameters on the response parameters is the main goal of this work. Here, the most influential parameters are speed, feed rate, and the depth of cut. The response parameters are the metal removal rate and Ra. In the present work, machining is performed on EN24 alloy steel, and the objective is to achieve the specified material removal rate (MRR) and surface finish. The EN24 is a very high-strength steel alloy that is widely used in aircraft and heavy vehicle crankshafts, connecting rods, gearshafts, etc. To find the optimum set of process parameters, a Taguchi design of experiment with an L16 orthogonal array was used. Later, the experiment results are optimized by gray relational analysis (GRA). In the proposed work, the minimum surface roughness and the maximum MRR are obtained. The parameters that greatly influence obtaining the optimum result are the feed rate and the speed of machining.

The forming process uses a specific amount of stress to cause permanent deformation of the workpiece to achieve the desired shape without any material removal. Many materials have less formability because they crack when we form them by the conventional forming process, and failure happens. The forming limit of materials can be increased by utilising high-strain-rate forming processes. In this work, an electro-hydraulic process was used for forming the Al 5052. An electromagnetic forming machine with a 10 kJ rated capacity, die, and pressure chamber was used to perform the experiments. Before the experimental work, ABAQUS-CAE software was used to simulate the electro-hydraulic process. Dynamic loading was used as boundary conditions, i.e. for loading on a sheet. Applied dynamic loading on the sheet caused plastic deformation in the sheet. The simulation results were validated against existing literature results. Based on the simulated results, experiments were conducted, and validation of the simulation results with the experiments was also performed. The dome height obtained in simulation as well as in the experiments was compared for their results validation and was comparable within an acceptable range of variation.

Developing thin-film composite membranes that simultaneously exhibit high water permeability and ion rejection (IR) remains a persistent challenge in desalination research. Here, we report the fabrication of polyamide (PA) membranes embedded with holey molybdenum disulfide nanosheets via controlled interfacial polymerization. The introduction of nanoscale Mo-rich pores within MoS2 provides low-friction water transport channels, while maintaining effective ion exclusion. Systematic optimization of interfacial polymerization conditions-specifically monomer contact time of 60 s each and nanosheet loading of 0.01 wt % resulted in an optimal water flux (WF) of similar to 96 L m(-2) h(-1) and IR of similar to 99.4%, outperforming both pristine PA and nonporous MoS2-based membranes. Molecular dynamics simulations revealed that water molecules align preferentially along hydrophilic Mo-edge sites, forming ordered, high-density transport channels responsible for the observed flux enhancement. Together, the experimental and computational results establish holey MoS2-embedded PA membranes as a promising platform for next-generation nanofiltration and desalination technologies.

AA1100 sheets have a wide range of applications in different industries, such as automotive, aerospace, heat exchangers, and nuclear sectors and in its application, joining and forming play an important role. In this process, a simple toolset, which includes a die, a punch, and a punch holder, is used to produce the joint. It is favoured in applications where the sheets interlock without undergoing significant plastic deformation. However, joints created through clinching typically exhibit poor formability. Due to its high strain rate capabilities, impulse electromagnetic (EM) forming plays a critical role in addressing this limitation. This manuscript compares the formability of EM forming in tailored clinched and non-clinched 1 mm sheet thickness AA1100 workpieces at 4.50 kV discharge voltage. An analysis of the magnetic field developed in the rectangular spiral coil and the Lorentz force exerted on the workpiece is conducted, and the dome height is validated through experimental results. A detailed analysis is provided to examine the safe and fracture points at various discharge voltages for the tailored sheets. Additionally, explicit LS-DYNA software was used for the numerical analysis of clinching and EM forming of non-clinched workpieces. The numerical and experimental results are comparable and lie in the acceptance range. The formability of formed clinched is 35% higher than that of non-clinched workpieces at 4.50 kV discharge voltage. The fracture limit of the non-clinched sheet is higher compared to the clinched sheet. The novelty of this research lies in the formability analysis of tailored clinched AA1100 sheets and an in-depth understanding of fracture behaviour under high strain rate conditions, employing analytical, experimental, and numerical approaches.

The need for thin and highly deformable textile reinforcements is constant in sectors like thin composites, catching nets, and complex construction designs (like dome-shape). The conventional rectangular-patterned meshed wovens are used in thin composite structures as reinforcement at the commercial level. These woven textiles are bidirectional and exhibit approximately the same strength along both axes. However, these conventional rectangular-patterned mesh designs show poor impact stress distribution capacity. Interestingly, very thin and fine mesh designs are available in nature. One such example is the spider web structure. These structures have evolved with time and optimised their mesh pattern design for better impact damage resistance and load transfer. In this study, the basalt fibre reinforced mortar textile composites are considered for the investigation due to their growing interest in civil and construction applications. To demonstrate how the mesh geometry in textiles significantly influences the stress transfer, energy absorption, and deformation of reinforcements under various impact situations, three different geometries, (a) square shape mesh, (b) diamond-shaped mesh, and (c) bio-inspired spider web mesh, are modelled and meshed based on the reference geometry's meshing pattern and dimensions. The results of numerical simulations show that a meshed reinforcement design inspired by spider-orb-web has improved mechanical features compared to conventional square and diamond shape mesh designs under high velocity impact loading.

In this process, the magnetic field pressure forces the driver to deform radially inward; sequentially, the D9 steel tube gets accelerated and forced to impact the SS316 end plug, causing a joint between the two. Experiments and metallurgical characterization were conducted by changing the working length of the field shapers and end plug shape at different voltages. The effect of change in end plug geometry, change in voltage, and change in field shaper working length was studied. The results were compared based on the values of the welded length, wavelength and crest height for the joined samples. The metallurgical characterization was performed using optical microscopy, the scanning electron microscope (SEM) and energy-dispersive x-ray spectroscopy (EDS). The micro-hardness test of the joined samples was also performed. To test whether the gap between the joint was present or not, helium leak tests were performed. For the confirmation of the strain hardening, hardness tests were performed near the joint interface.

Electromagnetic joining is a high energy rate and high-speed forming process. In this work, the aluminium tube was crimped over the aluminium, copper, and brass core by using the pulse discharge energy of the capacitor bank. A unique type of double solenoidal coil is used to carry out the research work on electromagnetic crimping. The compression-shear test was used to test the strength of the joints. The increase in the discharge energy also increases the joining strength. The maximum compressive strength when the discharge energy was 6.2 kJ was found to be 5.82, 5.51, and 4.5 MPa with aluminium, brass, and copper core, respectively. To study the distribution of the tube on the metal core microstructure at the interface was also analyzed, and it was found that the gap was 0–12 μm along the circumference for the 6.2 kJ discharge energy. The hardness at the interface was studied, and it was found that because of the impact of the tube with high velocity on the base core, the hardness value gets increased near the interface. Numerical simulations were also carried out to observe the deformation pattern and the maximum impact velocity. In the numerical study, the magnitude of the magnetic field and the Lorentz force was studied.

In this article, Finite element modelling is described to simulate aluminium powder's electromagnetic radial powder compaction process. Electromagnetic powder compaction technique is considered a high strain and high-speed powder forming technique in which solenoid coil with uniformly tapered step field shaper is used as forming tool for powder compaction process. In this process, the packing tube that holds the powder acts as a driving medium for the momentum transfer. During experiments, aluminium powder is kept in an electrically conductive driver tube material (in this study, Al 6063 tube). This process utilizes the Lorentz forces for compacting powder to give the required strength for the powder metallurgy component. This paper mainly develops a non-coupled finite element model to simulate the aluminium powder's electromagnetic powder compaction process. A versatile software Ansys Maxwell was used to analyze the intensities of the distribution of the electromagnetic fields during the electromagnetic forming process. The current curve obtained in the experiment is used as input loading conditions for analyzing electromagnetic fields. After that, for structural analysis of the powder compaction process, Ls-Dyna explicit software is used. The Geologic cap model was established in Ls-Dyna Multiphysics software for modelling powder deformation behaviour. The Johnson-Cook strength model was used to describe the packing tube's deformation. The FEM analysis helped predict the results of the final shape and size of electromagnetic powder compaction. The developed simulation model has been validated with a series of experiments resulting from the compaction of aluminium powder.

Electromagnetic impact welding is defined as solid-state welding in which weld is produced by the high-velocity impact of parts under controlled conditions. Due to this high-velocity impact, metallic bonding between the components occurs. Electromagnetic impact welding applies the electromagnetic principles postulated in the 19th century and later demonstrated. In this welding method, a high-intensity current flows near a conducting material, an eddy current is generated around the material. The induced eddy current repels the primary current, and a repulsive force known as Lorentz force develops on the material. Electromagnetic impact welding is one of the best methods of joining dissimilar metals having a huge difference in their melting point. Due to the Lorentz force, one part impacts the other part and causes the two parts to get welded. This work simulated electromagnetic impact welding on Ls-Dyna using an EM module. The field shaper and flyer tube material is copper, whereas the tube and end-plug material are steel. This study performed many simulations with different joining parameters.

The surface condition of pavement influences traffic safety, operating speed, manoeuverability, driver comfort and service volume. Generally, the service quality provided by pavement surface is evaluated based on its roughness. International Roughness Index (IRI) is a roughness indicator used globally. Even though the measurement of IRI is very costly, it gives a standardised method of pavement unevenness evaluation. This study attempts to relate pavement roughness with the speed of different classes of vehicles. Pavement roughness and traffic flow characteristics were collected from thirteen sites in Calicut city. Traffic data was collected using a Transportable Infrared Traffic logger (TIRTL), while geometric data was collected manually. Surface roughness was measured using the Machine for Evaluating Roughness Using Low-cost Instrumentation (MERLIN), and the Cundill roughness equation was used for IRI calculation. As IRI increases, the Free-Flow Speed (FFS) and Peak Hour Speed (PHS) of different vehicle classes reduce. The reduction in FFS is linear with IRI, whereas a negative logarithmic relationship can be observed in the case of PHS.

The main objective of this article is to perform the turning operation on an EN36B steel work-billet with a tungsten carbide tool, to study the optimal cutting parameters and carry out an analysis of flank-wear. Experimental and simulation-based research methodology was opted in this study. Experimental results were obtained from the lab setup, and optimisation of parameters was performed using RSM (response surface methodology). Using RSM, cutting-tool flank-wear was optimised, and the cutting parameters which affect the flank wear were determined. In results main effect plot, contour plot, the surface plot for flank-wear and forces (Fx, Fy and Fz) were successfully obtained. It was concluded that tool flank-wear is affected by depth of cut, and that flank-wear generally increases linearly with increasing cutting-speed, depth of cut and feed-rate. To validate the obtained results, predicated and measured values were plotted and were in very close agreement, having an accuracy level of 96.33% to 98.92%.

This research aims to compact pure aluminum (Al) powder in a radial direction using the electromagnetic forming method. The pure Al powder was placed inside the Al tube and closed rigidly with end plugs. The Al tube used here acts as a force-transmitting medium to compact the powder using Lorentz forces and hold the powder intact. In this process, electromagnetic Lorentz forces were utilized to consolidate the powder. A copper solenoid coil with the help of a field shaper is used to generate the Lorentz forces. These forces were obtained when a high magnitude electrical current passes through the solenoid coil and its induced effect current in the adjacent tube. The radially acting magnetic field pressure deforms the Al tube; subsequently, the Al powder gets consolidated inside the tube. Thereby, a highly denser Al compact is obtained through a new technique. In this study, the effect of compaction voltage on various mechanical properties of the compact was studied. After successfully consolidating Al powder in the Al tube, the microstructures of the compacted samples were analyzed to characterize the porosity and distribution of powder particles using a scanning electron microscope and optical microscope results. The final diameter of the compressed samples was measured at several locations using Vernier callipers. Archimedes principle was used to determine the densities of the consolidated powder sample to ascertain the sintered density of the samples at various energies. Hardness tests were conducted on normal cross sections using Brinell hardness and Vickers hardness tester.

The present research's objective is to investigate the electromagnetic radial powder compaction process and its effect on the densification, microstructure and mechanical properties of the Al 6061 alloy powder. Cylindrical product has been prepared from Al 6061 powder using the electromagnetic powder compaction method. In this method, electromagnetic force shrinks the packing tube and utilises the deformation of the tube to compact the Al 6061 powder. The electromagnetic forces were generated between the field shaper's inner cylindrical surface and the outer surface of the packing tube when a high voltage current is flowing through the solenoid coil. In this study, the Al 6061 powder is compacted at various discharge voltages such as 13 kV, 14 kV, 15 kV and 16 kV using a 20 kV and 40 kJ capacity electromagnetic forming machine. Sintering is performed on the compacted samples at 620 ? for 1 h in an N-2 tubular furnace. The simulation was carried out using loosely coupled multi-physics software, and simulated results were validated with the experimental results. Ansys Maxwell is used to analyse the electromagnetic field, and Ls-Dyna is used for structural analysis. To describe the deformation behaviour of the packing tube, the Cowper -Symonds model was used. The deformation in the compact and stress-strain variation was analysed using simulation results and experimental results. The effect of field shaper on powder compaction is investigated using the magnetic field analysis of the Ansys Maxwell results. The velocity of the packing tube is analysed for various input discharge voltages. The Vickers micro-hardness of electromagnetic powder compacted samples increases with compaction voltage. Finally, the results predicted by numerical simulation were verified with experimental results and found in good agreement.

A fully-coupled 3-D model of FSW was developed for 4–mm-plates of AA6061-T6 aluminum alloy based on the Finite Volume Method in ANSYS Fluent 14.5 software. Two types of the model, one with the tool and another without tool, were developed for different tool geometry, and analysis was done for temperature distribution in the workpiece and tool using system coupling for the first model and workpiece only in later one. A parametric study was carried out at different tool rotational speeds regarding temperature distribution and material flow analysis for all tool geometries at a single rotational speed. The behavior of materials was changed when passing through the different tools, and it was affected by thermal history, viscosity, and strain rate for particular tool geometry. Temperature-dependent material properties and a user-defined function viscosity code have been incorporated in the model, considering the workpiece as a non-Newtonian viscous fluid. A better material mixing was observed in the case of threaded pin geometry using a steady-state laminar flow model. All tapered tool geometries were unable to mix material properly just below and around the pin tip due to very low-velocity magnitude in this region, which may lead to a kind of defect. The asymmetric temperature distribution was observed in the workpiece. At higher rotational speed, peak temperature was observed higher in the workpiece, and the heat flow was more in the tool. Validation of the model was done by performing experiments.

The electromagnetic crimping process lies in the category of solid-state mechanical joining technique. This technique has great potential to produce dissimilar joints. The electromagnetic crimping process is used to produce the crimping of the joint between the copper tube and aluminium rod. The numerical model was validated based on the measured crimped diameter of the tube and also based on the temperature. The validated numerical model was used to study the effect of the field shaper tapered angle on the impact velocity of the flyer, plastic strain in the tube, and the magnetic field produced around the tube. For this study, the tapered angle of the tube used was 14.4 degrees, 15.2 degrees, 15.9 degrees, 16.7 degrees and 17.4 degrees. The other parameters related to the field shaper such as outer diameter, total length, inner diameter, and working length were kept constant. From this study, it was found that with the increase in the tapered angle of the field shaper, and maintaining the other parameters constant the impact velocity of the tube, magnetic field and plastic strain developed in the tube also increases.

There are many conventional forming processes used in industries such as hydraulic forming and die-punch forming. High strain rate forming is a process of strain hardening in which the yield strength of the material increases, and therefore we can deform materials like aluminium and steel beyond their forming limit. One of the high strain rate forming processes currently under study is electro-hydraulic forming (EHF). In this work, the design of the experimental setup for EHF has been proposed and prepared for performing. Numerical simulations were also performed for EHF in Abaqus for materials Al 5052 and Al 6061 T6. Commercial Al, Al 5052, and Al 6061 series were deformed by EHF high-energy pressure pulse inside a conical die. The dome height of forming sheets at different input parameters was quantified and analysed. Dynamic loading was applied on a sheet and allowed it to deform plastically. The simulated results were validated based on the results obtained from the experiments. After that, a simulation model ran for the same dome height and was carried out to obtain results for Al 5052 and Al6061 T6 alloy.

Electromagnetic forming is a high strain rate and high-speed forming process. This manuscript uses an electromagnetic forming technique to predict the failure zone in forming AA 6061. Concerning the die, entry radius is made using the experimental and simulation approach. Simulations performed to free-formed dome height test of AA 6061 of 1 mm thickness with dimension 200 mm × 200 mm in commercially available computational Finite Element Method (FEM) software. The FEM software utilized for the purpose is the LS-Dyna EM module specially designed for EMF application and uses a robust coupling method. In the experimental result, shear failure of the blank occurs at the dome's base, similar to the simulation result. The failure occurs due to the extreme shear stress generated between the blank and die cavity opening. Intense pressure and the relatively sharp edge of the die entry radius contribute to excessive shear stress in the region. An increase in the discharge energy causes the shearing of the blank at the bottom of the dome.

Active cooling-based atmospheric water generators, despite their growing demand, continue to be energy intensive and offer poor collection efficiencies (energy consumption per liter of water production). Despite progress in micro-/ nanofabrication techniques and functional coatings, advanced surfaces have not been successfully scaled onto such harvesters to accelerate condensation and improve their efficiencies. Here, we present a scalable dual-nanostructured hierarchical surface that comprises sporadically distributed bundles of randomly oriented faceted microcones having facets composed of nanostructures, which are either bumps or ridges. Condensate removal on this surface occurs via drop-to-film coalescence, followed by film shedding in the form of macrodrops. Compared to a conventional plain metal surface used for condensation, the improvement in latent heat transfer coefficient using a hierarchically textured surface ranged from 19.9% at a subcooling of similar to 8 degrees C to 1048.4% at a subcooling of similar to 1 degrees C in laboratory scale experiments, subcooling being defined with respect to the dew point. To demonstrate utility at industrial scale and to ensure scalability of the modified surfaces, we create a prototype assembly comprising a tube-fin heat exchanger with hierarchically textured fins, cooled using a standard refrigeration cycle, producing similar to 25 L of water per day. The prototype containing hierarchically textured fins provides similar to 10.8% enhanced water collection at similar to 10.4% improved average collection efficiency compared to the traditional water generator when tested in outdoor conditions.

A fully-coupled 3-D model of FSW was developed for 4 mm plates of AA6061-T6 aluminum alloy based on the Finite Volume Method (FVM) in ANSYS Fluent 14.5 software. Two types of the model; one with the tool and another without the tool was developed for different tool geometry and analysis was done for temperature distribution in the workpiece as well as in tool using system coupling for the first model and workpiece only in later one. A parametric study was performed at different tool rotational speed regarding temperature distribution, and material flow analysis was carried out for all tool geometries at a single rotational speed. The material behaves differently when passes through the different tools and it was affected by thermal history, viscosity, and strain rate for particular tool geometry. Temperature-dependent material properties and a user-defined function (UDF) code of viscosity have been incorporated in the model considering the workpiece as a non-Newtonian viscous fluid. A better material mixing was observed in the case of threaded pin geometry by using a steady-state laminar flow model. All tapered tool geometries were unable to mix material properly just below and around the pin tip due to very low-velocity magnitude in this region, which may lead to a kind of defect. An asymmetric temperature distribution observed in the workpiece and at higher rotational speed peak temperature observed higher in the workpiece, and the flow of heat was more in tool. Validation of the model was done by performing experiments.