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RMD™ welding has been developed for a variety of steels to regulate the rate of metal transfer effectively during the short-circuiting mode of the GMAW process. To achieve the desired weld quality,...

In this study, the microwave hybrid heating process has been exploited to produce optimized joints of SS304/SS316. Three input parameters: materials of the specimens to be joined (X), grain-size of...

Equal Channel Angular Pressing (ECAP) is one of the most innovative Severe Plastic Deformation (SPD) methods used for grain refinement of materials up to ultra-fined or Nano structured level which ...

The magnesium alloys are considered as biodegradable implant materials due to its biocompatibility and mechanical properties. The light weight structure also made it more demanding in industries su...

Zr and its alloys are considered as strategic materials for nuclear industry. In nuclear industries, zirconium and its alloys are mostly used to manufacture the tubes for reactors. The properties of the end component i.e. tube is fully dependent on the material processing route and the final microstructure. Therefore, in the present review paper, brief description of zirconium and its alloys is provided, bringing in the effect of various phase stabilizers and the microstructures after processing. Additionally, the processing route of Zr and Zr–Nb alloys are explained in terms of primary and secondary processing. In primary processing, the production of usable shapes is obtained through ingot melting followed by secondary operations such hot rolling or forging. Further, optimization of mechanical properties can be done by controlling the microstructure using various thermo-mechanical processes. The secondary processing such as cold working and/or annealing also helps to control the final microstructure to large extent. The microstructure control is fully dependent on the dominant deformation mechanism during the hot deformation. The dominant deformation mechanism depends on relative ease with which following processes occur; dislocation generation and glide, cross slip and climb and, diffusion. The possible restoration mechanisms for different Zr-alloys are discontinuous dynamic recrystallization (DDRX), continuous dynamic recrystallization (CDRX), rotational recrystallization (RRX), geometric dynamic recrystallization (GDX), dynamic recovery (DRV) accompanied by grain growth (GG). There are various techniques which helps to understand the hot deformation behaviour of any material. These techniques are; analysis of stress–strain data, development of processing maps, development of constitute equation. At the end, present paper summarises the work related to processing map, findings of processing map in terms of safe processing parameter, dominant deformation mechanism, role of activation energies during deformation of Zr–Nb alloys and their different phases (i.e. single α or β phase, or two phase α + β).

Biomaterials are the most emerging and promising field in total joint arthroplasty (TJA) as these materials gain their popularity in the ageing population. With steep growth in population and an un...

Nickel (Ni)-titanium (Ti) shape-memory alloy (SMA) is a functional material that has received a higher demand in aerospace industries, biomedical industries, actuator, and sensor industries owing to the property of superelasticity and shape memory effect. In addition, SMAs offer better mechanical and corrosion-resistant properties. In this current work, cryo treatment of NiTi alloy has been carried out to investigate the change in the properties. NiTi SMA prepared by powder metallurgy are cryo treated for 12 hours to 48 hours. Further, a corrosion study has been performed on the cryo-treated NiTi samples with the variation in corrosion time to know the effect on the morphology and the hardness. It is found that cryo-treated NiTi shows higher resistance to corrosion than the non-treated sample. The present work is an attempt to find out the effect of cryo treatment on the hardness and corrosion behavior of NiTi SMA. In the scanning electron microscope (SEM) analysis, it is observed that with the increase in cryo treatment time, NiTi (martensite) phase increases. Similar phases are present in both untreated and cryo-treated NiTi pellets. Out of all cryo-treated NiTi pellets, 24 hours cryo-treated NiTi has a lower percentage of corroded area with an increase in the corrosion exposure time. Corrosion preferentially starts at the pit area and progresses toward the Ti-rich area. The hardness value increased for 48 hours cryo-treated sample when compared with other cryo-treated and untreated NiTi pellets.

In present experimental work, 310 SS alloy has been welded by the TIG welding using design of experiment and grey relation optimization techniques. The input parameters, i.e., welding current, welding gas flow rate, and welding voltage, have been selected to perform the TIG welding. The same filler material was used during the welding process to investigate the mechanical and microstructure properties. The design of experiment and grey relation optimization techniques were used to optimize the effect on hardness and tensile strength of the welded joints. The experiments were performed as per the L9 orthogonal array obtained by the design of experiment methodology. The 65 A, 12 V, and 7.5 gas flow rate optimum setting of input parameters provides the better results for the effective hardness and tensile strength. The most significant parameters, i.e., welding current with 84.93% and welding voltage with 65.09%, were obtained for hardness and tensile strength, respectively.

Electrical discharge coating (EDC) process is used to deposit material on workpiece surface from sacrificial or green compact tool electrode in an electrical discharge machine. The paper presents the mechanism of EDC using green compact electrode and powder mixed dielectric methods. The tool electrode material, electrode size, process parameters, and type of dielectrics can directly affect the surface integrity of workpiece. Here, a process map of EDC as a function of process parameters, its classification, advantages, and applications for a wide range of engineering materials offers a proper template for the evaluation of coating phenomena. This study shows that EDC is an economic process as compared to other costlier techniques. Additionally, the effect of various EDM and EDC parameters on surface integrity and tribological behavior of deposited coatings is studied with their pros and cons. Finally, the current research trends of EDC and its challenges are elaborated.

The paper provides an introduction to biomaterials covered and their available types, such as metal, ceramic, polymer, and composites. Biomaterials are structures, devices, or materials that may repair or implant tissue. Biomaterials are biocompatible that have high mechanical strength, and need a long time to break down. A biomaterial is any natural or synthetic material that regularly touches the human body or is utilized to replace or restore biological tissue—metallic systems in the body and numerous ceramic and polymeric implant materials and systems. Polymers as biomaterials have had a significant impact on medical technology development. Furthermore, features of biomaterials such as mechanical, physical, and chemical qualities have been detailed to assist users in selecting the best biomaterial for their needs based on these properties. While these materials do not replace human tissues’ function, they have good physical and mechanical qualities that allow them to be used as body tissue substitutes. Apart from this, biomaterials are applied in various fields, including medicine and pharmacy. Biodegradable polymeric biomaterials, in particular, offer the advantage of being able to be broken down and removed once their purpose is completed. The most common biomaterials are used in tissue engineering, medicine delivery systems, orthopedic, orthodontic, wound healing, and cardiovascular applications. The conclusion summarizes that biomaterials are the most advantageous in medical science. Biomaterial and cellular biology researchers have been working to make biomanufacturing technologies more broadly available for a long time. The main area of focus is medicine, where technology is critical in studying and preventing uncommon diseases.

Laser welding is used in critical component production when tight tolerances like minimal distortions and residual stresses are required. Laser beam welding offers a lower heat input, a smaller heat affected zone, lower residual stresses, minimum distortions, and greater mechanical joint characteristics than conventional welding does. In order to simulate the laser welding process used on SS316L plates, the Gaussian heat source model was used. The model is developed and simulated with volumetric heat source model with APDL coding using ANSYS. The thermal profiles at the joint cross sections via welded area, interface across joints is taken for the analysis. The maximum temperature was observed at the fusion zone and associated zones. The residual stresses are analysed in the same path and found the stresses are in safe limits of base material. Predicted and experimentally measured residual stresses are close agreement with 10%.

The present study aimed at assessing mechanical and durability characteristics of ground granulated blast furnace slag (GGBS)-based geopolymer composites at 5%, 10%, 15%, 20%, 25%, and 30% replacement proportion of silica fume at 12 molarity of NaOH. Mechanical properties were assessed using compression and tension tests, whereas durability characteristics were evaluated using ultrasonic pulse velocity test (UPV), acid test, and rapid chloride permeability test (RCPT), and water absorption (WA) test. Additionally, reduction in mass and strength were also determined due to the acid action on the developed composites. A correlation of compressive strength was also established with the splitting tensile strength, UPV, RCPT, and WA. The presence of silica fume and high NaOH concentration in GPC tends to improve the mechanical strength up toa certain level. UPV values obtained were falling in the range of medium to good category. Chloride ion penetration and water absorption values were reduced by around 23% and 26%, respectively, at 10% silica fume replacement. Mass loss and strength loss were reduced as the % of silica fume increased. A good correlation of compressive strength was obtained with tensile strength, UPV, and RCPT with a coefficient of determination of 0.9681, 0.9665, and 0.9208, respectively. Poor correlation was obtained between compressive strength and water absorption.

Inconel 600 super alloy is chromium rich alloy having excellent oxidation and corrosion resistance at elevated temperatures. Due to these excellent properties, it is widely used in aerospace components such as blades, shafts and aircraft gas turbines. To know the high temperature deformation behaviour, Inconel 600 is hot deformed at elevated temperature ranging from 950 °C to 1100 °C with different strain rates range from 0.001 s−1 to 1 s−1. The true stress-true strain curves are plotted using the data obtained from hot compression. The true stress-true strain curves revealed that the deformation at lower strain rates showing softening for entire range of deformation temperature. Whereas, deformation at higher strain rate revealed strain hardening for entire range of deformation temperature. Softening could be due to dynamic recrystallization (DRX) or the instability in the deformed microstructure.

The present study aims to evaluate the influence of latent heat effect during phase change in a three-dimensional finite element numerical simulation of arc welding. A mathematical model is developed to incorporate the effect of latent heat of phase transformation using enthalpy formulation. The accuracy of the developed model was initially validated using available results in the literature and found consistent prediction. The validated numerical model is used to predict the temperature distribution, weld width, depth of penetration, melting efficiency with and without incorporating the effect of latent heat of fusion, solidification vaporization. The results obtained from a developed model incorporating the latent heat effect are in good agreement with the experimentally measured values, whereas a considerable deviation is observed between the predicted values and experimental values without considering the effect of latent heat. It is found that without considering the latent heat effect in the model, the mean error is 14%, 24.6%, 22% and 29.6% for peak temperatures, weld width, depth of penetration and melting efficiency respectively. Therefore, it can be concluded that the effect of latent heat of fusion, solidification, and vaporization is significant for analysis involving phase change and must be accounted for during numerical simulations.

In the present short review of manufacturing techniques of metal matrix composites (MMCs), aluminium and magnesium MMCs are reviewed in terms of their application and properties. Additionally, the ...

The Ni-Cr-Mo steel samples carburised by surface mechano-chemical case carburising treatment (SMCT) were subjected to post low temperature annealing to relieve excessive residual stress and to indu...

Among the emerging new welding technologies, friction stir welding (FSW) is used frequently for welding of high strength aluminium alloys, which are difficult to weld by conventional fusion welding...

Mathematical modelling and simulation plays a crucial role in the fabrication of patient-specific three-dimensional (3D) printed porous scaffold implant material. After simulation, the patient-spec...

In the present review article, influence of S and Mn on microstructure and mechanical properties is studied. Additionally, effect of manganese and sulfur on the wear property of grey cast iron was also reviewed. The data from different experiments were taken under consideration and studied for the examination of the alloyed cast iron. The study describes that on increasing the manganese content of the grey cast iron, wear coefficient and hardness decreases and impact energy increases. The main motive of addition of manganese is to control the adverse effect of sulfur on the mechanical properties of grey cast iron. Moreover, the presence of manganese counter the formation of FeS, which is the reason for hot shortness in the alloy.

The effect of alloying element addition in grey cast iron is great interest of materials developers. In the same context, the effect of adding niobium on mechanical properties of grey cast iron is reviewed. Microstructure and hardness test are reviewed to examine the mechanical properties of alloyed grey cast iron. The study indicated that increasing niobium results in increasing hardness due to which wear rate reduces and also reduces the lamellar spacing between the graphite layers. The reduction in lamellar spacing is due to decreases in eutectic temperature with the addition of niobium. Additionally, mechanical properties including hardness and wear resistance were enhanced after adding niobium.

Magnesium and its alloys can also be used as a degradable implant as a ceramic material which is highly applicable in biomedical industries. As medical devices require a strong surface integrity of the parts as well as high geometric precision. Therefore, it is necessary to find the optimal surface parameters in order to minimize the risk of inflammatory reactions, reduce friction or increase cell adhesion for optimal fitting, mechanical stability, and biocompatibility. Hence, present work emphasized on the effect of input parameters such as distributor current (A), work on time (B), work off time (C) on surface roughness during the Electric Discharge Machining (EDM) of pure magnesium (Mg). In the present work, Taguchi and TLBO analysis are used to obtain the optimal parametric combination to achieve better surface quality.

For many years titanium-based biomedical devices are gaining a promising place in modern society. Titanium is one of the best suitable materials for manufacturing bio implants and its application areas are orthopedics, dentistry etc. There are many features possess by titanium which make it appropriate are its biocompatibility, resistance to corrosion, wearing, osteoporosis etc. The Cp- Titanium and titanium-based alloys are categorized in three ways depending upon its microstructure such as (α + β), α- type, β-type and comparative analysis are done its behavior, stability through SEM. This review paper discussed the conventional and modern methods of fabricating the bio-implants and also summarizes the various additive manufacturing techniques.

With the utilization of the weight reduction process and electrochemical measurements, we recognized that the extract of Terminalia chebula can go about as a corrosion inhibitor for low carbon steel using sulfuric acid as corrosive media. This extract shows great corrosion inhibition effectiveness at specific concentrations of the inhibitor. It is observed that the inhibition efficiency increases with increasing the inhibitor concentration and it decreases with increase in temperature. The surface morphology of steel has also studied by using scanning electron microscopy and atomic force microscopy. Further, the Langmuir adsorption isotherm was used to check the adsorption behavior, and we performed the DFT calculations to show the energy difference between the HOMO and LUMO.

Grey cast iron is used to make brake disc due to its high damping vibration resistance and low cost. In the present work, effect of silicon addition on microstructure and mechanical properties of grey cast iron is reviewed. Results of microstructure and mechanical properties are compiled, which are affected due to the addition of silicon in grey cast iron. From the review, it is found that the volume of soft graphite flakes increases i.e. grain size increases which reduces the hardness of grey cast iron, on increasing the silicon content. Similarly, tensile strength reduces as a function of silicon addition. Hardness and wear rate depends on the phase of microstructure and the size of graphite flakes. Maximum hardness was obtained at 3.33% of silicon content.

Powder bed fusion process is one of the basic technique associated with additive manufacturing. It follows the basic principle of manufacturing the product layer by layer and their fusion. A heat source focuses its heat over a powder base material and heats the selected cross section area. Sources like laser beam, electron beam and infrared beam are used as heating tool. The process of heating allows the powder to take the shape of the intended object. Powder bed fusion process is compatible to every engineering material such as metals, ceramics polymers, composites etc. this technique is widely used in many industrial sectors such as aerospace, energy sector, transportation etc. A comprehensive overview on powder bed fusion process is presented in this review paper. Other popular techniques like selective laser melting (SLM), selective laser sintering (SLS), and electron beam melting (EBM) are also reviewed.

In the present study, a reanalysis of Magnesium based metal matrix composites made by powder metallurgy has been done. The Properties of the powder metallurgy products are highly influenced by some basic parameters like; type of reinforcement, weight or volume fraction of reinforcement, compaction pressure, sintering temperature and sintering time, etc. That is why the present study was focused to investigate the effect of these parameters on the mechanical properties of magnesium based Metal Matrix Composites (MMCs). It was observed that the hard ceramic particles like Al2O3, SiC, B4C, TiO2, TiC and etc. are reinforced in the magnesium matrix to enhance the strength, hardness and other properties. The strength and hardness increases on addition of these hard ceramic particles but ductility is reduced. It has been also observed that the metallic reinforcement like Titanium increases both the strength as well as the ductility of Magnesium based MMCs.

In these decades, there has been an increasing demand for magnetic field-assisted surface finishing processes in the industries. It is due to specific features available in the magnetic assisted surface finishing process; these are contactless and effectively controlling of magnetic forces in the intricate passage. These processes are hybridized by modification in the existing conventional surface finishing process or by clubbing two or more unconventional surface finishing processes. Magnetic Abrasive Flow Finishing (abbreviated as MAFF) process is an unconventional process used for internal cylindrical surface finishing, intricate and complex inside profile geometry. It is a hybrid process that gives a combined effect of AFM and the MAF process. MAFF was developed by the researchers Sahijpal Singh and H.S. Shan in the 2000s. They modified the AFM by applied an electromagnet around the workpiece. The main drawbacks of AFM’s process were low material removal rate and time-consuming process. MAFF was an advancement of AFM, in MAFF process material removal and surface finishing both considerable optimize. MAFF has a broader range of applications in electronics manufacturing of aerospace, semiconductor, automotive components, and medical components like biopsy needle.

A powered ankle foot orthotic (AFO) device has been designed not only for patients having foot drop problem but also improve the movement of ankle joint for patients with lower limb disabilities. Different materials like poly lactic acid (PLA), polypropylene and ABS are been used to be designed and analyzed with computer aided design (CAD) and Finite Element Analysis software and which help to select the best material for fabrication purpose. This research article presents an externally powered portable ankle foot orthosis fitted with microcontroller, stepper motor to provide dorsiflexion and plantar flexion assistance during patients walking suffering from foot drop. At first the 3D model has been analyzed which designed in CAD module with selected material using analysis software and then mechanical structured AFO has been developed on the basis of GAIT parameters accordingly the AFO is assembled. The aim of this paper is to design, manufacture and delivering customized AFO that is patient specific.

The addition of any alloying element alters the various properties of developed alloy, wherein mechanical properties influence significantly. The present work reviews the effect of molybdenum (Mo) and copper (Cu) addition in grey cast iron. It alters the few mechanical properties such as tensile strength, hardness and toughness of grey cast iron and are covered in this review article. It is reported that on increasing the percentage of copper and molybdenum in grey cast iron, tensile strength and hardness increases and impact energy decreases. But, beyond a certain amount of copper and molybdenum addition, there is a negligible effect on the hardness. Thus the main role of copper and molybdenum addition, is to reduce the volume of graphite flakes and increase the content of pearlite in microstructure of gray cast iron.

The present review paper complies the information of Ti and its alloys from basic processing to mechanical properties, along with various microstructure and heat-treatment processes. The basic processing routes and reaction to develop pure titanium from ore is explained. The role of stabilizers on pure titanium and their classifications as α-phase or β-phase stabilizers are explained with the details of respective elements. The various kinds of microstructure available in Ti or its alloys are shown and explained. The microstructure of alloy can be altered with help of processing conditions, composition and/ or cooling rate and medium. The resulted microstructure obtained after heat treatment of various Titanium alloy are lamellar, bimodal, equiaxed, basket-weave, acicular and widmanstatten, which exhibits different mechanical properties. Generally, Titanium alloy with fully lamellar structure shows higher fracture toughness and crack resistance while equiaxed structure shows high cycle fatigue resistance. Cooling rate and cooling medium also results in different microstructure. It was observed that water cooled titanium alloys shows highest hardness due to martensite formation because of rapid cooling followed by air and furnace cooling.

Solution heat treatment and Cryogenic treatment of Al6082 aluminium alloy were experimentally carried out at Temperature 520 °C and −183 °C temperature by using muffle furnace and by dipping the specimen in liquid nitrogen solution bath respectively. The soaking time is varied from 10 min to 24 h in four step (10 min, 30 min, 60 min and 24 h). The variation in the tensile strength and hardness were evaluated. The tensile strength and hardness increases as a function of cryogenic duration. The results were compared with as received and solution treated specimen. The microstructure of the solution and cryo-treated specimen were studied by optical microscope. The grain size refinement was recorded in cryo-treated specimen. The grain size refinement increases with increase in the duration of cryo-treatment. The fractography of broken tensile specimen were done using SEM to discuss about ductile and brittle fracture.

In this study, the hardness and surface roughness of selective laser-melted parts have been evaluated by considering a wide variety of input parameters. The Invar-36 has been considered a workpiece material that is mainly used in the aerospace industry for making parts as well as widely used in bimetallic thermostats. It is the mechanical properties and metallurgical properties of parts that drive the final product’s quality in today’s competitive marketplace. The study aims to examine how laser power, scanning speed, and orientation influence fabricated specimens. Using ANOVA, the established models were tested and the parameters were evaluated for their significance in predicting response. In the next step, the fuzzy-based JAYA algorithm has been implemented to determine which parameter is optimal in the proposed study. In addition, the optimal parametric combination obtained by the JAYA algorithm was compared with the optimal parametric combination obtained by TLBO and genetic algorithm (GA) to establish the effectiveness of the JAYA algorithm. Based on the results, an orientation of 90°, 136 KW of laser power, and 650 mm/s scanning speed were found to be the best combination of process parameters for generating the desired hardness and roughness for the Invar-36 material.

The present paper focuses on evaluating the bonding strength interfaces between the contact materials such as AISI 304L and Ti-6Al-4V via. the friction welding (FW). Experimental tests are performed by considering the process parameters such as friction time, rotational speed and friction pressure, mechanical properties were evaluated. The rotational speed of 1800, 1600, 2100, 2300 and 2500 rpm were considered in the study. The response surface methodology (RSM) is used to predict the outcomes of the work. Experimental tests were revealed that the friction pressure of 160 MPa, 7 sec of friction time and speed of 2300rpm are the optimal parameters based on the joint strength. Also, observed that the aluminum interlayer thickness of 1.25 μm on the Ti-6Al-4V side and 1.38 μm on the AISI 304L side. The tensile strength of 143.39 MPa was noticed at the interface area. The RSM response generates the curved potential line frequency range with 6.5% elongations. Results confirm that, the response surface methodology outcomes and experimental values were in close agreement.

Environmental and human-friendly welding is the need of the hour. In this context, this study explores the application of the regulated metal deposition (RMD) technique for ASTM A387-Gr.11-Cl.2 steel plates. To examine the effect of metal-cored filler wire (MCFW), MEGAFIL 237 M was employed during regulated metal deposition (RMD) welding of 6 mm thick ASTM A387-Gr.11-Cl.2 steel plates. The welding was carried out at an optimized current (A) of 100 A, voltage (V) of 13 V, and gas flow rate (GFR) of 21 L/min. Thereafter, the as-welded plates were examined for morphological changes using optical microscopy. Additionally, the micro-hardness of the as-welded plates was measured to make corroboration with the obtained surface morphologies. In addition to this, the as-welded plates were subjected to heat treatment followed by surface morphology and micro-hardness examination. A comparison was made between the as-welded and heat-treated plates for their obtained surface morphologies and microhardness values. During this, it was observed that the weld zone of as-welded plates has a dendritic surface morphology which is very common in fusion-based welding. Similarly, the weld zone of heat-treated plates has a finer and erratic arrangement of martensite. Moreover, the obtained surface morphologies in the weld zone of as-welded and heat-treated plates have been justified by their respective hardness values of 1588.6 HV and 227.3 HV.

Thermal barrier coating is critical for thermal insulation technology, making the underlying base metal capable of operating at a melting temperature of 1150 °C. By increasing the temperature of incoming gases, engineers can improve the thermal and mechanical performance of gas turbine blades and the piston cylinder arrangement. Recent developments in the field of thermal barrier coatings (TBCs) have made this material suitable for use in a variety of fields, including the aerospace and diesel engine industries. Changes in the turbine blade microstructure brought on by its operating environment determine how long and reliable it will be. In addition, the effectiveness of multi-layer, composite and functionally graded coatings depends heavily on the deposition procedures used to create them. This research aims to clarify the connection between workplace conditions, coating morphology and application methods. This article presents a high-level overview of the many coating processes and design procedures employed for TBCs to enhance the coating’s surface quality. To that end, this review is primarily concerned with the cultivation, processing and characteristics of engineered TBCs that have aided in the creation of specialized coatings for use in industrial settings.

The global energy situation requires the efficient use of resources and the development of new materials and processes for meeting current energy demand. Traditional materials have been explored to large extent for use in energy saving and storage devices. Graphene, being a path-breaking discovery of the present era, has become one of the most-researched materials due to its fascinating properties, such as high tensile strength, half-integer quantum Hall effect and excellent electrical/thermal conductivity. This paper presents an in-depth review on the exploration of deploying diverse derivatives and morphologies of graphene in various energy-saving and environmentally friendly applications. Use of graphene in lubricants has resulted in improvements to anti-wear characteristics and reduced frictional losses. This comprehensive survey facilitates the researchers in selecting the appropriate graphene derivative(s) and their compatibility with various materials to fabricate high-performance composites for usage in solar cells, fuel cells, supercapacitor applications, rechargeable batteries and automotive sectors.

This review article focuses on the aluminum-based metal matrix composites (Al-based MMCs). Studies or investigations of their mechanical and tribological properties performed by researchers worldwide in the past are presented in detail. The processing techniques and applications for Al-based MMCs are also documented here. A brief background on the composite materials, their constituents, and their classification, as well as the different matrix materials and particulates used in Al-based MMCs, can be found in this review. Then, an overview of dual-particle-size reinforced composites, heat treatment of Al alloys, and temper designations used in heat treatment are also included. In addition, the factors influencing the mechanical and wear properties of Al-based MMCs are discussed. The primary objective is that both present and future researchers and investigators will be assisted by the comprehensive knowledge compiled in this article to further explore and work towards the betterment of society in general.

Geopolymer concrete, because of its less embodied energy as compared to conventional cement concrete, has paved the way for achieving sustainable development goals. In this study, an effort was made to optimize its quality characteristics or responses, namely, workability, and the compressive and flexural strengths of Ground Granulated Blast-furnace Slag (GGBS)-based geopolymer concrete incorporated with polypropylene (PP) fibers by Taguchi’s method. A three-factor and three-level design of experiments was adopted with the three factors and their corresponding levels as alkali ratio (NaOH:Na2SiO3) (1:1.5 (8 M NaOH); 1:2 (10 M NaOH); 1:2.5 (12 M NaOH)), percentage of GGBS (80%, 90%, and 100%) and PP fibers (1.5%, 2%, and 2.5%). M25 was taken as the control mix for gauging and comparing the results. Nine mixes were obtained using an L9 orthogonal array, and an analysis was performed. The analysis revealed the optimum levels as 1:2 (10 molar) alkali ratio, 80% GGBS, and 2% PP fibers for workability; 1:2 (10 molar) alkali ratio, 80% GGBS, and 2.5% PP fibers for compressive strength; and 1:2 (10 molar) alkali ratio, 80% GGBS, and 1.5% PP fibers for flexural strength. The percentage of GGBS was found to be the most effective parameter for all three responses. The analysis also revealed the ranks of all the factors in terms of significance in determining the three responses. ANOVA conducted on the results validated the reliability of the results obtained by Taguchi’s method. The optimized results were further verified by confirmation tests. The confirmation tests revealed the compressive and flexural strengths to be quite close to the strengths of the control mix. Thus, optimum mixes with comparable strengths were successfully achieved by replacing cement with GGBS and thereby providing a better path for sustainable development.

In recent years, researchers have proposed a variety of sustainable ways of achieving maximal lubricant efficacy with the least amount of lubricant. As an alternative to traditional lubricating procedures, these planned solutions have been highly embraced by scientific groups. This paper provides a comprehensive review of modern cooling/lubrication technologies and their influence on titanium alloy milling, grinding, and turning. Selected studies on recent advances in the lubrication system, such as power consumption, cutting forces, surface finish, and so on, are examined. The effect of various cutting fluids on the machining of titanium alloys has also been investigated. According to the prior state of the art, lubricating techniques and lubrication types have a considerable influence on the machining efficiency of titanium alloys.

Significant advances in the field of composite structures continue to be made on a variety of fronts, including theoretical studies based on advances in structural theory kinematics and computer models of structural elements employing advanced theories and unique formulations. Plate vibration is a persistently interesting subject owing to its wider usage as a structural component in the industry. The current study was carried out using the Co continuous eight-noded quadrilateral shear-flexible element having five nodal degrees of freedom, which is ground on first-order shear deformation theory (FSDT). For small strain and sufficiently large deformation, the geometric nonlinearity is integrated using the Von Kármán assumption. The governing equations in the time domain are solved employing the modified shooting technique along with an arc-length and pseudo-arc-length continuation strategy. This work explored the effect of fiber angle on the steady-state nonlinear forced vibration response. To explain hardening nonlinearity, the strain and stress fluctuation throughout the thickness for a rectangular laminated composite plate is determined. The cyclic fluctuation of the steady-state nonlinear normal stress during a time period at the centre of the top/bottom surfaces is also provided at the forcing frequency ratio of peak amplitude in a nonlinear response. Because of the variation in restoring forces, the frequency spectra for all fiber angle orientations show significantly enhanced harmonic participation in addition to the fundamental harmonic.

Aluminum/carbon nanotubes composites have been processed by ingot metallurgy route. The cast ingots are subjected to 94% thickness reduction by groove rolling. In the composite with the lower concentration of aluminum/carbon nanotubes, the deformation of the matrix is homogeneous due to sparse distribution of aluminum/carbon nanotubes. However, on higher aluminum/carbon nanotube addition, sub-grain formation is confined closer to the prior aluminum/carbon nanotube regions indicating heterogeneity in deformation. Deformation texture of the rolled composites weakened with increasing aluminum/carbon nanotube content, due to the random distribution of sub-grain orientation near aluminum/carbon nanotube particles. Raman spectroscopy of the composite indicated two peaks first at 1336 cm−1 and the second at 1566 cm−1 corresponding to the D and G bands, respectively, and also the generation of surface defects in aluminum/carbon nanotubes during the rolling process.

Al alloys are the second most useful metal worldwide after the steel due to its high strength-to-weight ratio and corrosion resistance properties. In the present scenario, for creating contours in the sheet metals with close tolerances and high precision, laser beam cutting is preferred. During laser beam cutting of Al alloys, the reflectivity of the alloy possesses some difficulties to absorb the laser light. Such problems can be avoided using the shorter wavelength laser. This paper presents the modeling and optimization of kerf characteristics in Nd-YAG laser cutting of Al 6061-T6 sheet. In this study, kerf width (top and bottom side) and top kerf deviation are considered as kerf characteristics which are the functions of lamp current, pulse width, pulse frequency, and cutting speed. Box–Behnken design has been used for conducting the experiments and the experimental results have been further used for developing the response surface models and optimizing the responses using response surface methodology and grey relational analysis, respectively. Application of grey relational analysis has reduced the bottom kerf width by 12.5% and 7.75% along with straight and curved cut profiles respectively.

This paper shows the novel approach of Taguchi-Based Grey Relational Analysis of Ti6Al4V Machining parameter. Ti6Al4V metal matrix composite has been fabricated using the powder metallurgy route. Here, all the components of TI6Al4V machining forces, including longitudinal force (Fx), radial force (Fy), tangential force (Fz), surface roughness and material removal rate (MRR) are measured during the facing operation. The effect of three process parameters, cutting speed, tool feed and cutting depth, is being studied on the matching responses. Orthogonal design of experiment (Taguchi L9) has been adopted to execute the process parameters in each level. To validate the process output parameters, the Grey Relational Analysis (GRA) optimization approach was applied. The percentage contribution of machining parameters to the parameter of response performance was interpreted through variance analysis (ANOVA). Through the GRA process, the emphasis was on the fact that for TI6Al4V metal matrix composite among all machining parameters, tool feed serves as the highest contribution to the output responses accompanied by the cutting depth with the cutting speed in addition. From optimal testing, it is found that for minimization of machining forces, maximization of MRR and minimization of Ra, the best combinations of input parameters are the 2nd stage of cutting speed (175 m/min), the 3rd stage of feed (0.25 mm/edge) as well as the 2nd stage of cutting depth (1.2 mm). It is also found that hardness of Ti6Al4V MMC is 59.4 HRA and composition of that material remain the same after milling operation.

Filler powder plays an important role during microwave hybrid heating-based joining process. In this work, nano-size nickel powder has been taken as filler material for preparing SS304-SS304 butt joints. Effects of size of nickel powder on mechanical properties (strength and hardness) of joints have been investigated. Scanning electron microscope tests show that the joints possess uniform microstructure. Energy dispersive spectroscopy tests demonstrated the presence of elements (Chromium, iron, carbon, silicon, manganese, phosphorus) other than filler powder (Nickel) in the joint region thereby confirming complete melting of joint region and also transfer of carbon from graphite separator sheet to joint region during microwave processing. Micro-hardness test results showed that nano-size filler powder-based joints are less prone to surface wear than corresponding micro-size filler powder-based joints. Micro-tensile strength of nano-size nickel powder-based joints is also far better than micro-size filler powder-based joints.

Gyroid (G) and primitive (P) porous structures have multiple application areas, ranging from thermal to mechanical, and fall in the complex triply periodic minimal surface (TPMS) category. Such intricate bioinspired constructs are gaining attention because they meet both biological and mechanical requirements for osseous reconstruction. The study aimed to develop G and P structures with varying porosity levels from 40% to 80% by modulating the strut thickness to proportionally resemble the stiffness of host tissue. The performance characteristics were evaluated using Ti6Al4V and important relationships between feature dimension, strut thickness, porosity, and stiffness were established. Numerical results showed that the studied porous structures could decrease stiffness from 107 GPa (stiffness of Ti6Al4V) to the range between 4.21 GPa to 29.63 GPa of varying porosities, which matches the human bone stiffness range. Furthermore, using this foundation, a subject-specific scaffold (made of P unit cells with an 80% porosity) was developed to reconstruct segmental bone defect (SBD) of the human femur, demonstrating a significant decrease in the stress shielding effect. Stress transfer on the bone surrounded by a P scaffold was compared with a solid implant which showed a net increase of stress transfer of 76% with the use of P scaffold. In the conclusion, future concerns and recommendations are suggested.