Avinash Lakshmikanthan

The increasing application of glass fibre-reinforced polymer (GFRP) composites in structural systems requires reliable prediction of fatigue life and stiffness degradation under cyclic loading. This study experimentally investigates the fatigue behaviour of unidirectional S-glass/epoxy laminates...

Selective Laser Melting (SLM) has emerged as a promising additive manufacturing technique for producing high‐performance metallic components with complex geometries. However, achieving high densification and mechanical strength in super duplex stainless steel S2507 remains challenging due to the strong sensitivity of the process to laser parameters and thermal gradients. In this study, the effects of laser power, scan speed, and hatch distance on the density and ultimate tensile strength (UTS) of SLM‐fabricated S2507 components were systematically investigated using a Central Composite Design (CCD) experimental framework. Statistical modeling and analysis of variance (ANOVA) were employed to evaluate the significance of individual, quadratic, and interaction effects of the process parameters. The results revealed that scan speed is the most influential factor affecting both density and UTS, followed by hatch distance and laser power. Regression models developed for the responses showed high predictive capability with coefficients of determination of 0.9748 for density and 0.9708 for UTS. Density and UTS showed a strong third‐order model correlation, with an R ² of 0.98753. The Particle Swarm Optimization integrated with a Desirability Function Approach (PSO–DFA) determined single SLM conditions (laser power of 250 W, scan speed of 700 mm/s, and hatch distance of 50 μm) that simultaneously optimize multiple outputs (density of 7.908 g/cm ³ and UTS of 1323 MPa). Fractographic analysis revealed a clear transition in failure mechanisms, with ductile microvoid coalescence dominating under optimized conditions and brittle fracture features associated with lack‐of‐fusion defects under suboptimal processing parameters. These findings demonstrate that statistical modeling combined with metaheuristic optimization provides an effective framework for achieving high‐density, high‐strength S2507 components fabricated via SLM.

This work examines the effects of environmental and electrochemical conditions on the Time to Failure (TTF) and the Embrittlement Index (EI) of S2507 stainless steel and observes the alterations in microstructure which occurred before and on solution annealing. Experimental evidence demonstrates that high degradation of the material is caused by differences in the electrochemical potentials and exposures to corrosive conditions. The possible connection between TTF, EI and the material degradation is discussed with an emphasis on the influence of electrochemical stress on the progression of the hydrogen embrittlement. Also, examination of microstructures with the Scanning Electron Microscope (SEM) is used, offering an explanation of alterations in grain architecture and morphological distribution before and after solution annealing, which plays the role of explaining the behavior of the material at stresses. The results have noted that environmental and electrochemical conditions should be optimized to improve the durability of S2507 stainless steel.

AlSi10Mg alloy is widely used in marine, nuclear, petrochemicals, and food processing application parts operated in corrosive environments. A selective laser melting technique is used to print the AlSi10Mg parts. The printed specimen quality is influenced by laser power (LP), scan speed (SS), and hatch distance (HD). Taguchi L9 orthogonal array is used for experimental planning, analysis, and optimising printed parts' corrosion resistance. LP is the most dominating factor, followed by hatch distance and scan speed on the corrosion current (corrosion resistance of sample). Taguchi method determined optimal conditions (LP: 270 W; SS: 1000 mm/s; HD: 0.10 mm) improve the corrosion resistance by 16.1%. The microstructure under optimal conditions exhibits minimal corrosion and oxidation on the sample surface compared to sub-optimal conditions examined with scanning electron micrographs. Any novice user can use the results of the optimal conditions for reduced corrosion current in the printed parts.

Additive Manufacturing (AM) has rapidly evolved as a transformative technology, enabling the production of complex, highperformance materials that exhibit superior mechanical and tribological properties. Among the materials benefiting from this advancement is AlSi10Mg, an aluminum-silicon-magnesium alloy. AlSi10Mg has gained notable attention in industries like aerospace and automotive due to its excellent strength-to-weight ratio, high thermal conductivity, and robust wear resistance. These properties make it particularly suitable for lightweight, high-stress applications. This review consolidates state-of-the-art research on AlSi10Mg, specifically focusing on components produced through Selective Laser Melting (SLM), a prominent AM technique. SLM enables precise control over the materials microstructure and properties by melting and fusing powdered material layer-by-layer using a high-energy laser. The review delves into the influence of various SLM processing parameters, play a crucial role in influencing the alloy’s density, porosity, and internal stress, ultimately affecting its mechanical performance. Additionally, the review examines post-processing treatments enhancing AlSi10Mg’s strength, ductility, and fatigue resistance. Furthermore, the impact of these treatments on the alloy's microstructure, particularly the distribution and morphology of silicon phases within the aluminum matrix, is critically discussed, as they influence wear resistance and hardness. Major Findings: The major findings in this work are the potential of AM-produced AlSi10Mg as a high-performance material for industrial applications, highlighting current challenges and future research directions aimed at optimizing processing.

In the current work 17-4PH Stainless Steel is deposited using SLM process. It is widely used to build structural parts appropriate for automotive, medical, and aerospace applications. The 17-4 PH SS samples were deposited using technical parameters such as laser power: LP, Scan speed: SS, and hatch distance: HD) were studied to analyze the wear rate and ultimate tensile strength. Fracture and wear track analysis was performed using SEM analysis. The DOE-Taguchi method is applied for the experimental plan and analysis of the parametric contribution with a statistical evaluation technique: Pareto Analysis of variance. The fracture surface morphology of 17-4 PHSS samples at different conditions indicated different failure. 17-4 PHSS samples LP1SS1HD1 condition displayed ductile-brittle fracture followed by LP3SS3HD2 and LP3SS3HD3 conditions displaying ductile failure. The wear features indicate abrasive pits and thin grooves across few areas reduced intensity of wear compared to the extensive wear-out surface observed at conditions. The optimized conditions are validated and recommended to industry personnel for reference.

The cutting fluid’s lubrication affects a workpiece’s surface finish and cutting tool lifespan during turning. To optimize machine performance, appropriate lubrication is needed. Empirical experiments examined how machining factors affected a redesigned single-point cutting tool. Texturing the tool’s rake surface without altering its physical qualities was achieved utilizing super-drilling and laser engraving technologies. The goal was to build a surface junction that would keep cutting fluid in contact with the tool longer, improving lubrication and cooling. Both standard and customized tools were used to compare cutting force, temperature, power usage, and surface polish. Magnified pictures from the scanning electron microscope were utilized to analyze tool wear in different places. The improved tool dramatically lowered mean cutting force, heat output, and power consumption in experiments. The textured tool produced continuous chips instead of discontinuous/burnt chips due to increased friction at the tool–chip interface. The updated tool improved lubrication and cooling with cutting fluid.

New developments in thermal spraying processes may offer higher-quality alternatives to hard chrome plating and possibilities for hard chrome plating in a range of coating applications. These include spraying with high-velocity air fuel (HVAF) and new spray consumables. The low operating temperatures and accelerated particle velocity of the HVAF process enable investigation and development of a wide range of novel coating materials and applications. The High-velocity Air Fuel Process' quality and efficiency are primarily due to the broad combustion chamber and axial injection of the feedstock through it, as well as the relatively low combustion temperature of an air-fuel mixture and the low gas velocity that provides enough time for the mild heating of the powder particles. The current work discusses the inventive thermal spray procedure used for SAE 1008 carbon steel, a cost-effective substrate material. All of the compositions that were treated have undergone microstructure investigations. A scratch test is conducted in accordance with ASTM guidelines. Assessment of surface morphology clearly demonstrates the relationship between the evaluated parameters. According to the occurrence, scratch methods such as delamination, cracking, plastic deformation, and elastic deformation are highlighted. However, the findings of the scratch test showed that the samples' scratch resistance increased as the coating thickness rose. In comparison to samples with thinner coating, those with thicker coating demonstrated a stronger resistance to scratching. This is explained by the fact that coatings with a higher thickness and density can support the subsurface more effectively and stop cracks from scattering. This can retain the coating's integrity and stop more damage from occurring, improving scratch resistance. Better scratch resistance was displayed by the samples with denser microstructures and smoother surface morphologies. The outcome is greater scratch resistance because a higher density covering can withstand deformation and fracture better than a lower density layer. This is due to the mechanism of deformation and fracture in the coating material. This improvement in scratch resistance can be due to the composites' increased HVAF coating's hardness and adherence. The findings imply that using an HVAF coating to increase the scratch resistance of new nanocomposites may constitute a successful strategy.

The development of many engineered product applications for automobiles and aircraft parts has initiated the search for novel materials as alternatives to metal matrix composites (MMCs). Natural-fiber-reinforced polymer composites offer distinct advantages such as biodegradability, eco-friendliness, flexibility, low density, and higher specific strengths, etc. This study focuses on natural-fiber (hemp and banana)-fabric-reinforced polymer composites suitable for exterior-engineered parts. The hand lay-up process is used to fabricate these hybrid composites. Exterior-engineered products are highly susceptible to moisture, which can deteriorate their mechanical performances, including their tensile and flexural strength, thereby affecting the durability of the hybrid composites. Therefore, the hybrid composites are subjected to water absorption tests, where samples are immersed in distilled water for week-long intervals. After each interval, the water-absorbed specimens are tested for their tensile and flexural characteristics as per ASTM D-3039 and ASTM D-790, respectively. The moisture treatment had a notable impact on the composite materials, causing a slight decrease in the tensile strength by 2% due to the diminished lateral strength in the interlaminar fibers. Contrary to expectations, the flexural strength of the composites improved by 2.7% after the moisture treatment, highlighting the potential of the moisture treatment process to enhance the elastic properties of such composites. The dimensions of the specimens changed after the water immersion test, resulting in increased longitudinal and decreased lateral dimensions. The surface morphologies of the composite failure samples showed fiber delamination, fiber breakage, voids, and matrix fractures.