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Purpose The purpose of this study is to find the best geometries among the cylindrical, enamel and honeycomb geometries based upon the mechanical properties (tensile test, compression test and shear test). Further this obtained geometry could be used to fabricate products like exoskeleton and its supporting members. Design/methodology/approach The present research focuses on the mechanical testing of cylindrical, enamel and honeycomb-shaped parts fabricated through multi-jet printing (MJP) process with a wall thickness of 0.26, 0.33, 0.4 and 0.66 mm. The polymer specimens (for tensile, compression and shear tests) were fabricated using a multi-jet fusion process. The experimental results were compared with the numerical modelling. Finally, the optimal geometry was obtained, and the influence of wall thicknesses on various mechanical properties (tensile, compression and shear) was studied. Findings In comparison to cylindrical, enamel structures the honeycomb structures required less time to fabricate and had lower tensile, compressive and shear strengths. The most efficient geometry for fully functional parts where tensile, compressive and shear forces are present during application – cylindrical geometry is preferred followed by enamel, and then honeycomb. It was found that as the wall thickness of various geometries was increased, their ability to withstand tensile, compressive and shear loads also enhanced. The enamel shape structure exhibits greater strain energy storage capacity than other shape structures for compressive loads, and the strength to resist the compressive load will be lower. In the case of cylindrical geometries for tensile loading, the resisting area toward the loading will be higher in comparison to honeycomb- and enamel-based structures. At the same time, the ability to store the stain energy is less. The results of the tensile, compression and shear load finite element analysis using ANSYS are in agreement with those of the experiments. Originality/value From the insight of literature review, it is found that a wide range of work is done on fused deposition modeling (FDM) process. But in comparison to FDM, the MJP provide the better dimensional accuracy and surface properties (Lee et al., 2020). Therefore, it is observed that past research works not incorporated the effect of wall thickness of the embedded geometries on mechanical properties of the part fabricated on MJP (Gibson, n.d.). Hence, in this work, effect of wall thickness on tensile, compression and shear strength is considered as the main factor for the honeycomb, enamel and cylindrical geometries.

Superhydrophobicity is a surface property used in several sectors, including self-cleaning, drag reduction, improved buoyancy, and antibacterial behavior of the surfaces. The majority of available approaches for creating superhydrophobic surfaces (SHS) are complex and time-consuming. Goal: This article aims to fabricate the SHS by using Multi jet printer three-dimensional (3D) printing. Methods: The texture of cylindrical protrusions (diameter 300 Micro Meter (µm), pitch 400 and 500 µm) and pyramidical (side 200 µm, side by side distance 200 µm, and height 800 µm) micro-pattern were created using Three-Dimensional Printing (3DP) to achieve the SHS. Results: The fabricated geometries yielded a water contact angle of 145 and 148°, respectively. In order to enhance the durability and Water Contact Angle (WCA), 3D printed geometry was treated with an aqueous solution of silica nanoparticles and Hexafor 644-D, which increased the contact angles to 161 and 160° for cylindrical and pyramid patterns, respectively. The reported geometries are durable against peeling tape tests. Hence MJP, based on 3DP, can be used to fabricate the SHS having the geometries height in micron (µm).

The shortcoming of conventional manufacturing (CM) is that it cannot manufacture geometrically complex parts with high repeatability and good surface properties. In order to overcome these shortcomings of CM, additive manufacturing (AM) is the major alternative to the CM. However, the usefulness and performance of parts manufactured through AM are closely correlated with dimensional accuracy and surface roughness, SR (Ra). Therefore, an investigation was carried out in this study for dimensional accuracy and surface roughness of 3D printed parts fabricated in different orientations. In the investigation, four orientation patterns are considered. The part is lying on the base (A), part is lying on the long edge (B), part is lying on the short edge (C), and the part is inclined to 45°(D) to the surface of the base plate (refer to Fig. 2). Orientations, i.e., A, B, C, and D, were explored for the variations in dimensional deviation and SR. In addition, an analysis was carried out using scanning electron microscopy (SEM) on fabricated parts. The results obtained exhibit a variation in dimensional accuracy and change in SR with different part orientations. Among all orientations, the largest surface area of the component in contact with the base plate (A) was the most suitable.

Purpose A nut bolt joint is a primary device that connects mechanical components. The vibrations cause bolted joints to self-loosen. Created by motors and engines, leading to machine failure, and there may be severe safety issues. All the safety issues and self-loosen are directly and indirectly the functions of the accuracy and precision of the fabricated nut and bolt. Recent advancements in three-dimensional (3D) printing technologies now allow for the production of intricate components. These may be used technologies such as 3D printed bolts to create fasteners. This paper aims to investigate dimensional precision, surface properties, mechanical properties and scanning electron microscope (SEM) of the component fabricated using a multi-jet 3D printer. Design/methodology/approach Multi-jet-based 3D printed nut-bolt is evaluated in this paper. More specifically, liquid polymer-based nut-bolt is fabricated in sections 1, 2 and 3 of the base plate. Five nuts and bolts are fabricated in these three sections. Findings Dimensional inquiry (bolt dimension, general dimensions’ density and surface roughness) and mechanical testing (shear strength of nut and bolt) were carried out throughout the study. According to the ISO 2768 requirements for the General Tolerances Grade, the nut and bolt’s dimensional examination (variation in bolt dimension, general dimensions) is within the tolerance grades. As a result, the multi-jet 3D printing (MJP)-based 3D printer described above may be used for commercial production. In terms of mechanical qualities, when the component placement moves from Sections 1 to 3, the density of the manufactured part decreases by 0.292% (percent) and the shear strength of the nut and bolt decreases by 30%. According to the SEM examination, the density of the River markings, sharp edges, holes and sharp edges increased from Sections 1 to 3, which supports the findings mentioned above. Originality/value Hence, this work enlightens the aspects causing time lag during the 3D printing in MJP. It causes variation in the dimensional deviation, surface properties and mechanical properties of the fabricated part, which needs to be explored.

Accumulated heat input during layer deposition causes high residual stress in the Wire-Arc Additive Manufacturing (WAAM) components. The developed residual stress results in defects like distortion, delamination, cracks, and low fatigue life. To deal with such engineering problems, numerical methods have always been required. It gives an insight into the system that can be used for real-world applications. Consequently, a sequentially coupled finite element model has been developed to simulate the thermal–structural behavior of the feedstock during and after deposition in the WAAM process. Precisely, a novel multi-level layer-wise heat input approach characterized by four different stages is compared with the layer-wise single heat input strategy. The variation of thermal and residual stress distributions has been studied based on the different cases proposed related to layer-wise multi-level heat loading. A good agreement between predicted and experimentally observed temperature and residual stress values has been observed. The developed framework predicted thermal distribution with an average error of 9.71%, 9.13%, 7.57%, and 4.52% for case #1, case #2, case #3, and case #4, respectively. In addition to that, longitudinal stresses in the modeled component recorded a reduction of 17.94% for four-level heat input (case #4) compared to the respective value observed in case #1. Therefore, a multi-level heat input strategy is recommended over a single-level heat input approach for the components with small deposition lengths manufactured through the WAAM process.

Direct metal laser sintering (DMLS) technique of additive manufacturing has been proven to be the best technology for printing metallic components with higher density and better mechanical properties. However, due to higher surface roughness of the as-built metallic components, post-processing through shot blasting is the most recommended method for improving surface finish. In the present work, the optimum shot blasting conditions were explored for achieving desired surface roughness for the DMLS printed AlSi10Mg aluminum alloy plates. Three input parameters (viz., time, pressure and grit size) selected at three levels were used to formulate the design matrix. Consequently, 30 real-time shot blasting experiments were performed, and the results obtained as surface roughness were used to develop the quadratic model using response surface methodology. Further, the prediction effectiveness was verified using analysis of variance. The experimental results revealed that the effect of blasting pressure on the surface roughness was found to be positive and most significant (41.89%), followed by the negative influence of time of shot blasting (29.29%) and grit size of shots (23.71%). The predicted values of surface roughness (maximum and minimum) obtained at optimum set of process parameters were found to be in agreement (± 6%) with the experimentally measured data. The variations in surface roughness were further validated through scanning electron microscopy. The proposed mathematical model is effective, precise and promising for the prediction of surface roughness in the shot-blasted surfaces of additively manufactured aluminum alloys.

Selective laser sintering (SLS) is an additive manufacturing (AM) process, which is widely used for fabrication of end used products, directly from computer aided design (CAD) data. SLS process is usually used in different areas such as biomedical, automobile and aerospace industries. The major advantage of this process is that the designer can visualize and test the specimens before the full scale production of parts. Therefore, to achieve a good dimensional accuracy in order to fulfill the demands of these fields is a key parameter. Dimensional accuracy of SLS process is mainly influenced by geometry, process parameters and materials. It can only be enhanced by controlling the shrinkage of parts. Therefore, this work is carried out to analyze the effect of crucial contributing factors (i.e, laser power, bed temperature, layer thickness, scan spacing and orientation) for the shrinkage (CAD, thermal and volumetric) of duraform polyamide specimens. Face centered central composite (CCD) design is used for the collection of data. Response surface methodology (RSM) is used to monitor the effects as well as interactions of selected parameters, and for the development of regression models. Multi-response optimization of shrinkage along with composite desirability is employed for different optimized selected SLS parameters. It has been found that the laser power 41 W, bed temperature 170 °C, layer thickness 0.09 mm, scan spacing 0.15 mm and orientation 85.68 degree is a most significant optimized range of these parameters to improve the overall shrinkage measures of parts.

Wire-arc additive manufacturing (WAAM) has recently attracted researchers to produce metal components with a high-deposition rate. Many researchers are trying to establish the WAAM process as a high-deposition metal additive manufacturing (AM) process. A computationally efficient mathematical model used for the metal-AM process yields a framework for component qualification as per international standards. Since heat transaction in the AM process can control the thermal-field generated through continuous heat deposition. Therefore, the present study focuses on the critical review of multi-physics continuum modelling of WAAM at a macro-scale level. Thermo-mechanical model for WAAM has been discussed extensively, i.e., heat-source models, materials models, meshing strategy, and boundary conditions. Further, a review of the simulation results discussed as thermal fields, residual stress and distortion, and experimental validation to provide a critique of real-life experiments. Also, various residual stress/distortion mitigation techniques used in the WAAM have been compiled to provide a framework for future directions.

The proper implementation of sustainable manufacturing processes is an effective step towards a clean environment. The modern cooling strategies applied in the manufacturing sector have presented promising solutions that enable economic growth and ecological environment. In machining operations, cryogenic cooling and minimum quantity lubrication (MQL) have been extensively utilized to replace conventional cooling techniques. Thus, this work offers a detailed review of major works focused on manufacturing processes that use some of these sustainable cooling/lubrication modes (i.e., MQL, nanocutting fluids, nanofluid-based MQL strategy, and other miscellaneous MQL upgrades). The main driver of this study is to create a bridge between the past and present studies related to MQL and MQL upgrades. In this way, a new guideline can be established to offer clear directions for a better economic vision and a cleaner manufacturing process. Thus, this review has mainly focused on the machining of the most commonly used materials under MQL-related methods in conventional operations including turning, milling, drilling, and grinding. Current work provides a detailed insight into the major benefits, limitations, as well as mechanisms of cooling strategies that directly affects the machinability performance from a sustainable point of view. In summary, further potential upgrades are indicated so that it will help to drive more sustainable approaches in terms of cooling and lubrication environment during machining processes.

Purpose This paper aims to present a systematic approach in the literature survey related to metal additive manufacturing (AM) processes and its multi-physics continuum modelling approach for its better understanding. Design/methodology/approach A systematic review of the literature available in the area of continuum modelling practices adopted for the powder bed fusion (PBF) AM processes for the deposition of powder layer over the substrate along with quantification of residual stress and distortion. Discrete element method (DEM) and finite element method (FEM) approaches have been reviewed for the deposition of powder layer and thermo-mechanical modelling, respectively. Further, thermo-mechanical modelling adopted for the PBF AM process have been discussed in detail with its constituents. Finally, on the basis of prediction through thermo-mechanical models and experimental validation, distortion mitigation/minimisation techniques applied in PBF AM processes have been reviewed to provide a future direction in the field. Findings The findings of this paper are the future directions for the implementation and modification of the continuum modelling approaches applied to PBF AM processes. On the basis of the extensive review in the domain, gaps are recommended for future work for the betterment of modelling approach. Research limitations/implications This paper is limited to review only the modelling approach adopted by the PBF AM processes, i.e. modelling techniques (DEM approach) used for the deposition of powder layer and macro-models at process scale for the prediction of residual stress and distortion in the component. Modelling of microstructure and grain growth has not been included in this paper. Originality/value This paper presents an extensive review of the FEM approach adopted for the prediction of residual stress and distortion in the PBF AM processes which sets the platform for the development of distortion mitigation techniques. An extensive review of distortion mitigation techniques has been presented in the last section of the paper, which has not been reviewed yet.

Solar energy is a key component in meeting the increasing demands of the electrical power consumption in the society as solar energy is available in abundance, is free, clean and pollution free in nature. In order to obtain more power by gathering more irradiation from the sun, solar tracking mechanisms have been developed. Energy efficiency tracking systems from various systems has been reviewed in this paper. The increment in the power generated from such systems ranges from 5% to 60% with various tracking mechanisms. Moreover, installation of the tracking systems should be restrictedonly to the larger systems in order to compensate the energy used in tracking with the surplusenergy generated with the help of a tracking system. Additionally, different variants of solar tracking mechanisms are reviewed and observed to highlight that the tracking system with one-axis azimuthal tracking is most popularly used one. How to cite this article: Bhateja P, Gupta A, Sharma VS. Efficiency Enhancement of Photovoltaic Panels with Solar Trackers: A Review. J Adv Res Prod Ind Engg 2019; 6(3&4): 1-17. DOI: https://doi.org/10.24321/2456.429X.201904

Solar energy is of key importance to meet the increasing demands of the electrical power needs of the society as solar energy is available in abundance, is free, clean and pollution free in nature. In order to obtain more power by increasing the receptance of incident rays from sun, a solar tracking mechanism has been developed. This paper presents an energy efficiency case study of a single-axis solar tracker which converts solar energy to electrical energy. The tracker is programmed in such a way that it gets tilted to follow sun’s movement accurately throughout the day. It was observed that the generated power output with tracking is higher in comparison to the fixed PV system. How to cite this article: Bhateja P, Gupta A, Sharam VS. Energy Efficiency Studies - Modelling and Analysis of Solar Tracker System. J Adv Res Alt Energ Env Eco 2019; 6(3&4): 1-6. DOI: https://doi.org/10.24321/2455.3093.201902

A solar tracker is a traditional term used to describe devices that coordinate or align different payloads with the sun. The aim of the automatic sun tracking system is to retain the photovoltaic solar panel perpendicular to the sun throughout the year to make it more efficient. A solar power transforms sunlight into electricity. This automated sun tracking system helps generate power by automatically tuning the device for optimum sunlight. Through reducing light intensity, this system will automatically change its direction to reach maximum amount of light. Light intensity is the big problem with solar power generation. To produce the maximum energy, a solar panel must be upright and face-to-face with the light source. Because the sun moves all through the day as well as throughout the year, in order to produce as much energy as possible, a solar panel must be able to follow the sun’s movement. The approach is to use a light source tracking system to preserve the panel’s orthogonal location. Several tracking systems models exist, including passive and active systems with one or two freedom axes. Solar trackers are used with different sensors to dramatically increase the electrical power of the photovoltaic panel. Photovoltaic systems are rapidly becoming a fresh source of energy by capturing the solar radiation. Optimizing its power output is desirable in order to increase its efficiency. The panels must be aligned with the sun in order to optimize the power output of solar panels. It has been estimated that energy derived from solar panels can be expanded by 20 to 30% by using a tracking system instead of a stationary array. Over time, different approaches have been developed. Astronomical or time-based systems are the most popular, and then optical approaches are used to align the PV components with different image sensor types. How to cite this article: Taheem A, Sachdeva A, Sharma VS. Solar Tracker: A Review. J Adv Res Alt Energ Env Eco 2019; 6(3&4): 34-50. DOI: https://doi.org/10.24321/2455.3093.201904

This review focus on the effect of reinforcement and different manufacturing techniques on wear and mechanical properties aluminium matrix composites and hybrid composites. These materials have capacity to satisfying the demands of advanced engineering materials applications. These difficulties are satisfied due to improved mechanical properties, conventional processing technique and reducing fabrication cost of aluminium composites. In powder metallurgy, the crucial issue is the selection of sizes of the matrix and reinforcement powders, whereas a major challenge in liquid metallurgy is wettability between the reinforcement particles and molten alloy. The addition of Al2O3 particles in matrix increases the mechanical strength and wear resistance of composites. However, incorporation of these particles can reduce the wear performance of Al composites under severe conditions. The addition of graphite particles helps in the formation of a thick layer on the wear surface. It was found that the mechanical and wear properties of the single reinforcement composites are better as compared to pure aluminium and aluminium alloys regardless of the aluminium matrix composites fabrication technique. Further, it was also established that most of the hybrid composites demonstrate better mechanical and tribological properties as compared to single reinforcement composites. How to cite this article:Singh S, Gupta A, Sharma. Wear Behaviour of Aluminium Matrix Hybrid Composites: A Review. J Adv Res Mech Engi Tech 2019; 6(1&2): 13-22.

Ti-6Al-4V with its ELI variant is a potential biomaterial for structural implants. However, its poor resistance to plastic shearing results in poor tribological properties that hinders its widespread use in biomedical implants. Cryogenic treatment being an established technique for improving wear resistance and other mechanical properties of ferrous materials is applied on Ti-6Al-4V ELI alloy. To ensure comprehensive investigations, the widely studied microstructures of Ti-6Al-4V ELI, i.e., lamellar, martensite, two variants of bimodal and mill annealed are considered in this work. Deep cryogenic treatment at the soaking temperature (− 196 °C) for 24 h soaking time followed by tempering has been applied. The impact of cryogenic treatment has been assessed in terms of changes in the mechanical behavior including wear resistance, hardness, tensile properties and impact strength. The alterations in mechanical behavior due to cryogenic treatment are correlated with microstructure evolution. Cryogenic treatment has caused significant improvement in mechanical behavior of Ti-6Al-4V ELI alloy.

Huge demand of lightweight materials in aerospace, automotive and recreational goods enthuse the manufacturing sectors to further exploit the interesting characteristics i.e., high specific strength to weight ratio, wear resistance and stiffness1 with high thermal conductivity and lower co-efficient of thermal expansion. With this objective the effect of mixing alumina and/or graphite in aluminium 7075 hybrid nanocomposite was studied, w.r.t stirring time variation on mechanical properties (hardness, toughness and ultimate compressive strength) and validated by Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) to characterized AA7075/Al2O3/Gr hybrid composites. The impact of variation of mechanical stirring time followed by fixed ultrasonic time is investigated deploying Response surface methodology/ design of experiments. From the analysis it was observed that hardness, Ultimate compressive strength and toughness of developed nanocomposite generally improved with mechanical stirring combined with ultrasonic homogenisation, with some softness associated in case of graphite nano composited. Optimization results of weight percentage of alumina, graphite and stirring time are reported. How to cite this article: Singh S, Gupta A, Sharma VS. Investigating Properties of Hybrid Alumina/ Graphite Aluminium Matrix nano Composites. J Adv Res Mfg Mater Sci Met Engr 2019; 6(3&4): 8-20. DOI: https://doi.org/10.24321/2393.8315.201902

The procedure of tracking the sun depends on azimuth, altitude and declination angle of sun, latitude and longitude of a location and others. The orientation of sun around the earth can be tracked by using sun tracking mechanisms to collect the maximum percentage of incidents sun ray normal to the panel. This study is conducted to meet objective i.e. optimizing data handling. Three case studies have been implemented. In the first case, a computerized sun tracking device is assumed to rotate the photovoltaic panel as per the sun movement. The output is accurate, but it is expensive as typical multiple sensors, mechanical drive and microcontroller are used. In the second scenario, the solar panel is fixed at sun azimuth (ɸ) 180° and altitude 58° angle which causes more variations in the percentage of incident sun ray normal to the panel throughout the day. Whereas, in the third case, the panel is supposed to change its direction according to the 12 paths (trajectory) of sun instead of 365 paths and each path is comprised with the monthly average of the sun azimuth and altitude angle. This procedure will reduce data handling/ sun tracking cost as compared to the first case. How to cite this article: Taheem A, Sachdeva A, Sharma VS. Optimization of Sun Tracking Data Handling to Improve Efficiency of PV Module. J Adv Res Alt Energ Env Eco 2019; 6(1&2): 1-15. DOI: https://doi.org/10.24321/2455.3093.201901

A modified design of radiation furnace has been presented in which material is heated by flame directly impinging on it. In the existing furnace, the flame produced with gas fired burner (LPG/air) has been used to heat the material and avoid direct contact of flame with the material. Problems such as production lagging, greater fuel consumption, more furnace starting time, lower thermal performance, etc. were occurred in the existing design. In this study, an attempt has been made to improve the performance of the furnace with designing and arranging of burner’s location with respect to target surface. An array of combine swirl and axial flames directly impinging on the surface has been purposed to have got a uniform heat flux distribution over the surface of the material. Consequences such as uniform heating, faster production, significant reduction in fuel consumption and furnace restarting time, hardly any chamber’s constructional and maintenance costs were observed with the use of modified design. With the implementation of modified design, quantitative values of fuel consumption and time to heat one kg material were reduced up to 72.43% and 32.38% respectively. Similarly, furnace restarting time and refractory material for constructing the chamber were significantly reduced. Thermal performance and heat transferring rate were improved up to 1.66 and 0.7275-time exiting values, respectively with an exploration of furnace and burner design. How to cite this article:Taheem A, Sachdeva A, Sharma VS. Performance Evaluation of a Furnace Using Flame Directly Impinging on a Surface - A Case Study of Forging Industry. J Adv Res Prod Ind Engg 2019; 6(1&2): 12-20.

The manufacturing of parts from nickel-based superalloy, such as Inconel-800 alloy, represents a challenging task for industrial sites. Their performances can be enhanced by using a smart cutting fluid approach considered a sustainable alternative. Further, to innovate the cooling strategy, the researchers proposed an improved strategy based on the minimum quantity lubrication (MQL). It has an advantage over flood cooling because it allows better control of its parameters (i.e., compressed air, cutting fluid). In this study, the machinability of superalloy Inconel-800 has been investigated by performing different turning tests under MQL conditions, where no previous data are available. To reduce the numerous numbers of tests, a target objective was applied. This was used in combination with the response surface methodology (RSM) while assuming the cutting force input (Fc), potential of tool wear (VBmax), surface roughness (Ra), and the length of tool–chip contact (L) as responses. Thereafter, the analysis of variance (ANOVA) strategy was embedded to detect the significance of the proposed model and to understand the influence of each process parameter. To optimize other input parameters (i.e., cutting speed of machining, feed rate, and the side cutting edge angle (cutting tool angle)), two advanced optimization algorithms were introduced (i.e., particle swarm optimization (PSO) along with the teaching learning-based optimization (TLBO) approach). Both algorithms proved to be highly effective for predicting the machining responses, with the PSO being concluded as the best amongst the two. Also, a comparison amongst the cooling methods was made, and MQL was found to be a better cooling technique when compared to the dry and the flood cooling.

The Honeycomb structure is one of the most common natural structures used in sandwich panel cores. The Enamel structure’s mechanical properties were compared to the Honeycomb structure’s mechanical properties to investigate if the Enamel structure can improve the compressive strength, stiffness and energy absorption capabilities of sandwich panel cores and potentially replace the common Honeycomb structure. Also, the optimal cellular configurations for the Honeycomb and Enamel structures were explored. Indeed, it was found the Enamel structure can potentially replace the Honeycomb structure and a wall thickness of 1.2 mm and a wall length/cell radius of 8.14 mm will maximize the natural structures mechanical properties. Furthermore, it was found that both the natural structures have good compressive strength. Therefore, the natural structures with their optimal cellular configurations were integrated into a novel automobile floor mat to ensure the mat possesses good compressive strength to resist failure or permanent deformation. Moreover, the novel automobile floor mat has a design feature that offers an efficient debris capturing and removal system that adds value to the automobile floor mat.

In additive manufacturing, selective laser melting (SLM) and electron beam machining (EBM) are two key processes which are widely used for fabrication of Ti6Al4V based products. These fabricated products having outstanding properties are widely employed in automotive, aerospace, marine, biomedical as well as offshore applications. This chapter compares SLM and EBM along with different process parameters, which are involved for processing of Ti6Al4V structures. For deep understanding and to analyze the potential as well as capability of Ti6Al4V structures, their microstructure and mechanical properties are also discussed. Related literature review with key focus is also presented and analyzed. As per these analyses, the challenges and their solutions are presented for improvements.

Being one of the most important staple crops of the world, rice has played a vital role in slaking the calorie requirements of the masses in all the inhabitable continents of our planet. Regardless of this fact, there are many environmental concerns related to the rice production systems across the globe. One of the major worries is the emission of lethal greenhouse gases as a result of the different steps and procedures concerned with rice production and their contribution towards global warming. This study presents the status quo of the rice straw burning practice across the globe. It focuses on the greenhouse gas emissions as a result of the open field burning of rice residues and its direct effect on the environment, eventually contributing towards climate change. The study evidently shortlists the most profound regions contributing towards the open burning dilemma and the socio-political reasons associated with it. The study additionally discusses the different alternatives to straw burning with a clear-cut motive of throwing light on the opportunities that lie in the efficacious and sustainable utilization of homogeneous agricultural wastes. Different in-field straw management techniques related to the farmers and off-field methods related to the industry have been discussed. Predicated upon a survey of the life cycle assessment (LCA) studies across the globe, it is concluded that soil incorporation and electricity generation are the most environment friendly alternatives with an enormous scope of improvement in the coming future.

Recently, Additive Manufacturing (AM) has been widely used in many applications. For a particular AM component, the choice of available AM processes is critical to the component’s quality, mechanical properties, and other important factors. In that context, this article presents an efficient decision support system for the selection of an appropriate AM process. A novel hybrid Multi-Criteria Decision Making (MCDM) technique has been proposed to select an appropriate AM process from available AM processes. The Best Worst Method (BWM) is used to determine optimal weights of criteria and the Proximity Indexed Value (PIV) method is employed to rank the available AM processes. For benchmarking the abilities of an AM process, a conceptual model of spur gear was fabricated by four available AM processes viz., Vat Photopolymerization (VatPP), Material Extrusion (ME), Powder Bed Fusion (PBF), and Material Jetting (MJ). Additionally, Dimensional accuracy (A), surface roughness (R), tensile strength (S), percentage elongation (%E), heat deflection temperature (HDT), process cost (PC) and build time (BT) has been considered as most significant criteria. Further, sensitivity analysis has been performed to validate the reliability of the results. The results suggested that the Material Jetting (MJ) process produces dimensionally accurate and quality parts among available alternatives AM processes. The ranking obtained using the PIV method is consistent and reliable.

Recently, the urgency of improved machining performance and environmental sustainability has forced the manufacturer to seek for alternative cooling and lubricating agent/technique such as nano-fluid (NF)-assisted minimum quantity lubrication (MQL). In this context, the performances of aluminum oxide (Al2O3), molybdenum disulfide (MoS2) and graphite (C) NF-impinged MQL in turning of Ti alloy (grade II) using CBN tool were evaluated regarding the cutting force, cutting temperature and surface roughness. The cutting speed, feed rate, approaching angle and cutting conditions (i.e., NFs) were oriented following the Box–Behnken design-of-experiment. The experimental results showed that the graphite NF, compared to Al2O3 and MoS2, revealed the lowest cutting force, temperature and roughness. Moreover, it is evident from SEM images that graphite NF revealed a smoother machined surface and tool profile. This smooth tool and workpiece surface profile can be accredited to graphite’s role as a nano-lubricant and its breaking ability into smaller NFs under pressure. To make the study complete, the adaptive neuro-fuzzy inference system (ANFIS) was employed to predict, the response surface methodology (RSM) was used to mathematically model, and the composite desirability approach (CDA) was used to optimize the responses. A good agreement between the experimental and modeled observations was found; however, the ANFIS outperformed the RSM. Moreover, the analysis of variance exhibited that the cutting force and temperature were primarily influenced by the cutting speed and the surface roughness was afflicted mostly by the feed.

In machining of soft alloys, the sticky nature of localized material instigated by tool-work interaction exacerbates the tribological attitude and ultimately demeans it machinability. Moreover, the endured severe plastic deformation and originated thermal state alter the metallurgical structure of machined surface and chips. Also, the used tool edges are worn/damaged. Implementation of cooling-lubrication (C/L) agents to reduce friction at faying surfaces can ameliorate overall machinability. That is why, this paper deliberately discussed the influence of pure C/L methods, i.e., such as dry cutting (DC) and nitrogen cooling (N2), as well as hybrid C/L strategies, i.e., nitrogen minimum quantity lubrication (N2MQL) and Ranque–Hilsch vortex tube (RHVT) N2MQL conditions in turning of Al 7075-T6 alloy, respectively. With respect to the variation of cutting speed and feed rate, at different C/Ls, the surface roughness, tool wear, and chips are studied by using SEM and 3D topographic analysis. The mechanism of heat transfer by the cooling methods has been discussed too. Furthermore, the new chip management model (CMM) was developed under all C/L conditions by considering the waste management aspects. It was found that the R-N2MQL has the potential to reduce the surface roughness up to 77% and the tool wear up to 118%. This significant improvement promotes sustainability in machining industry by saving resources. Moreover, the CMM showed that R-N2MQL is more attractive for cleaner manufacturing system due to a higher recyclability, remanufacturing, and lower disposal of chips.

Surface grinding is a widely used machining process for finishing of materials. Industry is looking for materials and techniques which are more productive as well as environment friendly. Researchers have worked upon various aspects to improve the overall performance of surface grinding in context of environmental and economic issues. But no comprehensive review on surface grinding, which covers all technological issues related to the process, including modelling and simulation, has been reported yet. This review is on research and technological advancements in surface grinding. It discusses critical findings pertaining to these advancements and gives recommendations related to surface grinding.

Dry machining is undesirable to produce precision surface due to thermal adversities especially for a low melting point material such as Al 6061-T6. Likewise, the conventional flood cooling is neither economically viable nor eco-friendly. In this context, three novel cooling-lubrication (C/L) technologies namely the nitrogen gas cooling (NGC), nitrogen gas assisted minimum quantity lubrication (NGMQL) and Ranque-Hilsch vortex tube (RHVT) NGMQL are investigated along with the air cooling (AC) in turning with an attempt to reduce surface roughness (Ra) and tool flank wear (VBmax). The machining was conducted using uncoated WC insert at two-levels of cutting speed and feed rate; and, as medium of cooling/lubrication the nitrogen gas and/or canola oil is employed. The SEM and 3D topographic images were analyzed for the machined surfaces, worn tool surfaces and chips. Results showed that the RHVT-NGMQL revealed the least surface roughness and tool wear (∼75% improvement compared to other C/Ls). Notable wear modes were: in dry cutting the plastic deformation, BUE and adhesion; in NGC the BUE; in NGMQL the rubbing and adhesion; in RHVT-NGMQL the adhesion. In micro-level, no significant difference in chip structure was found for the studied C/L methods In addition, the Composite Desirability optimization was adopted to systematically minimize Ra and VB max concurrently. It was found that the optimum speed vc = 160 m/min and feed rate f = 0.06 mm/rev under RHVT-NGMQL C/L condition has the potential to generate a precision surface with a roughness value

This paper investigates the dimensional accuracy of selective laser sintered parts considering the effect of different process parameters, while processing duraform polyamide as the work material. The correlation between different process parameters and dimensional accuracy (performance measures) was established by developing mathematical models. The correlation coefficients (R2 = 0.860288), approximately close to 0.9, showed that the generated models are reliable and effectively predict the response within the domain of the selected process parameters. Analysis of variance was employed to check the adequacy of the developed models and also to determine the significance of the parameters. It was observed that dimensional accuracy increases with the increase in laser power, bed temperature and scan count. Scan spacing is found to be the most significant parameter; dimensional accuracy decreases with the increase in scan spacing. Optimization has been carried out with the use of response surface methodology and a desirable functional approach. Subsequently, the optimized parts were obtained and presented.