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In the present research, the AZ31 alloy is machined by wire-cut electric discharge machining (WEDM). The experiments were designed according to the Box-Behnken design (BBD) of response surface methodology (RSM). The input process variables, namely servo feed (SF), pulse on-time (Ton), servo voltage (SV), and pulse off-time (Toff), were planned by BBD, and experiments were performed to investigate the cutting rate (CR) and recast layer thickness (RCL). The analysis of variance (ANOVA) was performed to determine the influence of machining variables on response characteristics. The empirical models developed for CR and RCL were solved using Multi-Objective Particle Swarm Optimization (MOPSO). Pareto optimal front is used for the collective optimization of CR and RCL. The optimal solution suggested by the hybrid approach of RSM-MOPSO is further verified using a confirmation test on the random setting indicated by the hybrid algorithm. It is found that the minimum RCL (6.34 µm) is obtained at SF: 1700; SV: 51 V; Toff: 10.5 µs; and Ton: 0.5 µs. However, maximum CR (3.18 m/min) is predicted at SF: 1900; SV: 40 V; Toff: 7 µs; and Ton: 0.9 µs. The error percentage of ±5.3% between the experimental results and predicted solutions confirms the suitability of the proposed hybrid approach for WEDM of AZ31.

This study aims to investigate the influence of fibre orientation and varied incident energy levels on the impact-induced damage of S2/FM94, a kind of aerospace glass fibre epoxy/composite regularly used in aircraft components and often subjected to low-velocity impact loadings. Effects of varying parameters on the impact resistance behaviour and damage modes are evaluated experimentally and numerically. Laminates fabricated with four different fibre orientations 0/90/+45/−458s, 0/90/90/08s, +45/−4516s, and 032 were impacted using three energy levels. Experimental results showed that plates with unidirectional fibre orientation failed due to shear stresses, while no penetration occurred for the 0/90/90/08s and +45/−4516s plates due to the energy transfer back to the plate at the point of maximum displacement. The impact energy and resulting damage were modelled using Abaqus/Explicit. The Finite Element (FE) results could accurately predict the maximum impact load on the plates with an accuracy of 0.52% to 13%. The FE model was also able to predict the onset of damage initiation, evolution, and the subsequent reduction of the strength of the impacted laminates. The results obtained on the relationship of fibre geometry and varying incident impact energy on the impact damage modes can provide design guidance of S2/FM94 glass composites for aerospace applications where impact toughness is critical.

In the food industry, there are many varieties of technical blades with different contours as well as different cutting edge geometries. The evaluation of the ability of technical blades to separate (cut) animal tissues is not a simple task and is usually based on the evaluation of the cutting effects in a technological process. This paper presents a methodology for evaluating the cutting force of technical blades used in food processing. A specially made test stand with numerical control was used in the study. Its application enabled a comparison of cutting force values for four different cutting edge geometries of planar knives used in the skinning operation of flat fishes. A unique feature of the conducted research was the use of a relatively high cutting speed value of vf = 214 mm/s, which corresponded to the real conditions of this process carried out in the industry. Obtained test results allow unambiguously choosing the most advantageous variant of knife geometry from among four different variants used for the tests. The results showed a clear relationship between the cutting force value and the value of the tip angle of the blades tested: for blades with the lowest tip angle, the lowest cutting force values were obtained.

High impact polystyrene (HIPS) material is widely used for low-strength structural applications. To ensure proper function, dimensional accuracy and porosity are at the forefront of industrial relevance. The dimensional accuracy cylindricity error (CE) and porosity of printed parts are influenced mainly by the control variables (layer thickness, shell thickness, infill density, print speed of the fused deposition modeling (FDM) process). In this study, a central composite design (CCD) matrix was used to perform experiments and analyze the complete insight information of the process (control variables influence on CE and porosity of FDM parts). Shell thickness for CE and infill density for porosity were identified as the most significant factors. Layer thickness interaction with shell thickness, infill density (except for CE), and print speed were found to be significant for both outputs. The interaction factors, i.e., shell thickness and infill density, were insignificant (negligible effect) for both outputs. The models developed produced a better fit for regression with an R2 equal to 94.56% for CE, and 99.10% for porosity, respectively. Four algorithms (bald eagle search optimization (BES), particle swarm optimization (PSO), RAO-3, and JAYA) were applied to determine optimal FDM conditions while examining six case studies (sets of weights assigned for porosity and CE) focused on minimizing both CE and porosity. BES and RAO-3 algorithms determined optimal conditions (layer thickness: 0.22 mm; shell thickness: 2 mm; infill density: 100%; print speed: 30 mm/s) at a reduced computation time equal to 0.007 s, differing from JAYA and PSO, which resulted in an experimental CE of 0.1215 mm and 2.5% of porosity in printed parts. Consequently, BES and RAO-3 algorithms are efficient tools for the optimization of FDM parts.

Titanium and its alloys exhibit numerous uses in aerospace, automobile, biomedical and marine industries because of their enhanced mechanical properties. However, the machinability of titanium alloys can be cumbersome due to their lower density, high hardness, low thermal conductivity, and low elastic modulus. The wire electrical discharge machining (WEDM) process is an effective choice for machining titanium and its alloys due to its unique machining characteristics. The present work proposes multi-objective optimization of WEDM on Ti6Al4V alloy using a fuzzy integrated multi-criteria decision-making (MCDM) approach. The use of MCDM has become an active area of research due to its proven ability to solve complex problems. The novelty of the present work is to use integrated fuzzy analytic hierarchy process (AHP) and fuzzy technique for order preference by similarity to ideal situation (TOPSIS) to optimize the WEDM process. The experiments were systematically conducted adapting the face-centered central composite design approach of response surface methodology. Three independent factors—pulse-on time (Ton), pulse-off time (Toff), and current—were chosen, each having three levels to monitor the process response in terms of cutting speed (VC), material removal rate (MRR), and surface roughness (SR). To assess the relevance and significance of the models, an analysis of variance was carried out. The optimal process parameters after integrating fuzzy AHP coupled with fuzzy TOPSIS approach found were Ton = 40 µs, Toff = 15 µs, and current = 2A.

The enormous use of cutting fluid in machining leads to an increase in machining costs, along with different health hazards. Cutting fluid can be used efficiently using the MQL (minimum quantity lubrication) method, which aids in improving the machining performance. This paper contains multiple responses, namely, force, surface roughness, and temperature, so there arises a need for a multicriteria optimization technique. Therefore, in this paper, multiobjective optimization based on ratio analysis (MOORA), VIseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR), and technique for order of preference by similarity to ideal solution (TOPSIS) are used to solve different multiobjective problems, and response surface methodology is also used for optimization and to validate the results obtained by multicriterion decision-making technique (MCDM) techniques. The design of the experiment is based on the Box–Behnken technique, which used four input parameters: feed rate, depth of cut, cutting speed, and nanofluid concentration, respectively. The experiments were performed on AISI 304 steel in turning with minimum quantity lubrication (MQL) and found that the use of hybrid nanofluid (Alumina–Graphene) reduces response parameters by approximately 13% in forces, 31% in surface roughness, and 14% in temperature, as compared to Alumina nanofluid. The response parameters are analyzed using analysis of variance (ANOVA), where the depth of cut and feed rate showed a major impact on response parameters. After using all three MCDM techniques, it was found that, at fixed weight factor with each MCDM technique, a similar process parameter was achieved (velocity of 90 m/min, feed of 0.08 mm/min, depth of cut of 0.6 mm, and nanoparticle concentration of 1.5%, respectively) for optimum response. The above stated multicriterion techniques employed in this work aid decision makers in selecting optimum parameters depending upon the desired targets. Thus, this work is a novel approach to studying the effectiveness of hybrid nanofluids in the machining of AISI 304 steel using MCDM techniques.

The prospect of using metal-cored wires instead of solid wires during gas metal arc welding (GMAW) of 2.25 Cr–1.0 Mo steels embraces several challenges. The in-service requirements for the equipment made up of these steels are stringent. The major challenge faced by the manufacturers is temper embrittlement. In the current study, the temper embrittlement susceptibility of the welded joint was ascertained by subjecting it to step cooling heat treatment. A 25 mm thick 2.25 Cr–1.0 Mo weld joint was prepared using a combination of the regulated metal deposition (RMD) and GMAW processes incorporating metal-cored wires. After welding the plates were exposed to post-weld heat treatment followed by a rigorous step cooling heat treatment prescribed by API standards. The temper embrittlement susceptibility of the weld joint was ascertained by Bruscato X-factor as well as by formulating ductile-to-brittle transition temperature (DBTT) curves by carrying out the impact toughness testing at various temperatures. Detailed microscopy and hardness studies were also carried out. It was established from the study that the X-factor value for the welded joint was 15.4. The DBTT for the weld joint was found to occur at −37 °C which was well below 10 °C. Optical microscopy and scanning electron microscopy indicated the presence of carbides and the energy dispersive X-ray spectrometry studies indicated the presence of chromium and manganese-rich carbides along with the presence of sulfur near the grain boundaries. This study establishes a base for the usage of metal-cored wires particularly in high temperature and pressure application of Cr–Mo steels.

This study was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) [Project Number: 113M141] and Konya Technical University OYP Projects Coordination Unit [Project Number: 2014-OYP-86]. Tribological properties are important to evaluate the in-service conditions of machine elements, especially those which work as tandem parts. Considering their wide range of application areas, metal matrix composites (MMCs) serve as one of the most significant materials equipped with desired mechanical properties such as strength, density, and lightness according to the place of use. Therefore, it is crucial to determine the wear performance of these materials to obtain a longer life and to overcome the possible structural problems which emerge during the production process. In this paper, extensive discussion and evaluation of the tribological performance of newly produced spheroidal graphite cast iron-reinforced (GGG-40) tin bronze (CuSn10) MMCs, including optimization, statistical, graphical, and microstructural analysis for contact zone temperature and specific wear rate, are presented. For this purpose, two levels of production temperature (400 and 450 degrees C), three levels of pressure (480, 640, and 820 MPa), and seven different samples reinforced by several ingredients (from 0 to 40 wt% GGG-40, pure CuSn10, and GGG-40) were investigated. According to the obtained statistical results, the reinforcement ratio is remarkably more effective on contact zone temperature and specific wear rate than temperature and pressure. A pure CuSn10 sample is the most suitable option for contact zone temperature, while pure GGG-40 seems the most suitable material for specific wear rates according to the optimization results. These results reveal the importance of reinforcement for better mechanical properties and tribological performance in measuring the capability of MMCs. Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) 113M141 Konya Technical University OYP Projects Coordination Unit 2014-OYP-86

The study of microstructures for the accurate control of material properties is of industrial relevance. Identification and characterization of microstructural properties by manual measurement are often slow, labour intensive, and have a lack of repeatability. In the present work, the intermetallic phase ratio and grain size in the microstructure of known Mg-Sn-Al alloys were measured by computer vision (CV) technology. New Mg (Magnesium) alloys with different alloying element contents were selected as the work materials. Mg alloys (Mg-Al-Sn) were produced using the hot-pressing powder metallurgy technique. The alloys were sintered at 620 °C under 50 MPa pressure in an argon gas atmosphere. Scanning electron microscopy (SEM) images were taken for all the fabricated alloys (three alloys: Mg-7Al-5Sn, Mg-8Al-5Sn, Mg-9Al-5Sn). From the SEM images, the grain size was counted manually and automatically with the application of CV technology. The obtained results were evaluated by correcting automated grain counting procedures with manual measurements. The accuracy of the automated counting technique for determining the grain count exceeded 92% compared to the manual counting procedure. In addition, ASTM (American Society for Testing and Materials) grain sizes were accurately calculated (approximately 99% accuracy) according to the determined grain counts in the SEM images. Hence, a successful approach was proposed by calculating the ASTM grain sizes of each alloy with respect to manual and automated counting methods. The intermetallic phases (Mg17Al12 and Mg2Sn) were also detected by theoretical calculations and automated measurements. The accuracy of automated measurements for Mg17Al12 and Mg2Sn intermetallic phases were over 95% and 97%, respectively. The proposed automatic image processing technique can be used as a tool to track and analyse the grain and intermetallic phases of the microstructure of other alloys such as AZ31 and AZ91 magnesium alloys, aluminium, titanium, and Co alloys.

Belt grinding of flat surfaces of typical parts made of steel and alloys, such as grooves, shoulders, ends, and long workpieces, is a good alternative to milling. Several factors can influence the belt grinding process of flat surfaces of metals, such as cutting speed and pressure. In this work, the importance of pressure in the belt grinding was investigated in terms of technological and experimental aspects. The grinding experiments were performed on structural alloy steel 30KhGSN2/30KhGSNA, structural carbon steel AISI 1045, corrosion-resistant and heat-resistant stainless steel AISI 321, and heat-resistant nickel alloy KHN77TYuR. The performance of the grinding belt was investigated in terms of surface roughness, material removal rate (MRR), grinding belt wear, performance index. Estimated indicators of the belt grinding process were developed: cutting ability, reduced cutting ability for belt grinding of steels and heat-resistant alloy. It was found that with an increase in pressure p, the surface roughness of the processed surface Ra decreased while the tool wear VB and MRR increased. With a decrease in plasticity and difficulty of machinability, the roughness, material removal rate, reduced cutting capacity (Performance index) qper, material removal Q decreased, and the tool wear VB increased. The obtained research results can be used by technologists when creating belt grinding operations for steels and alloys to ensure the required performance is met.

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

Porous Lattice Structure (PLS) scaffolds have shown potential applications in the biomedical domain. These implants’ structural designs can attain compatibility mechanobiologically, thereby avoiding challenges related to the stress shielding effect. Different unit cell structures have been explored with limited work on the fabrication and characterization of titanium-based PLS with cubic unit cell structures. Hence, in the present paper, Ti6Al4V (Ti64) cubic PLS scaffolds were analysed by finite element (FE) analysis and fabricated using selective laser melting (SLM) technique. PLS of the rectangular shape of width 10 mm and height 15 mm (ISO: 13314) with an average pore size of 600–1000 μm and structure porosity percentage of 40–70 were obtained. It has been found that the maximum ultimate compressive strength was found to be 119 MPa of PLS with a pore size of 600 μm and an overall relative density (RD) of 57%. Additionally, the structure’s failure begins from the micro-porosity formed during the fabrication process due to the improper melting along a plane inclined at 45 degree.

The stringent demand to develop lightweight materials with enhanced properties suitable for various engineering applications is the focus of this research work. Industrial wastes such as fly ash (FA) and S-glass-fibres (GF) were used as reinforcement materials for high-strength alloy, i.e., Al 7005. Stir casting routes were employed for fabricating the four samples, Al 7005, Al 7005 + 5% GF, Al 7005 + 6% FA and Al 7005 + 5% GF + 6% FA. The extrusion process with different extrusion ratios (ER: 5.32:1, and 2.66:1) was used to examine the properties of all four samples. Extruded samples with ER: 5.32: 1 resulted in equiaxed grains with refined structure compared to stir casting parts. The effect of the extrusion process and the addition of reinforcements (GF and FA) on the gravimetric, electrochemical, and electrochemical impedance corrosion behaviour of Al 7005 composites in 1M HCl (Hydrochloric acid) solution were investigated. The results of all three corrosion methods showed that Al 7005 + 6% FA exhibited higher corrosion resistance. Corrosion rate of Al 7005, Al 7005 + 5% GF, Al 7005 + 6% FA and Al 7005 + 5% GF + 6% FA is found equal to 3.25, 2.41, 0.34, and 0.76 mpy, respectively. The FA particles remain inert and act as a physical barrier with corrosive media during the corrosion test. GF undergoes fibre degradation or disrupts the continuity of the glass network as a result of fibre leaching, which increases the corrosion rate in the sample. The gravimetric study showed that the corrosion rates decreased with an increase in extrusion ratio, which might be due to corrosion passivation increases and improved properties. The scanning electron microscopy reveals that corrosion fits, flakes and micro-cracks were observed more in the as-cast composites than that of extrusion composites, promoting the corrosion rate.

Surface roughness reflects the quality of many operational parameters, namely service life, wear characteristics, working performance and tribological behavior of the produced part. Therefore, tribological performance is critical for the components used as tandem parts, especially for the MMCs (Metal Matrix Composites) which are a unique class of materials having extensive application areas such as aerospace, aeronautics, marine engineering and the defense industry. Current work covers the optimization study of production parameters for surface roughness and tribological indicators of newly produced cast iron reinforced bronze MMCs. In this context, two levels of temperature (400 and 450 °C), three levels of pressure (480, 640 and 820 MPa) and seven levels of reinforcement ratios (60/40, 70/30, 80/20, 90/10, 100/0 of GGG40/CuSn10, pure bronze-as received and pure cast iron-as received) are considered. According to the findings obtained by Taguchi’s signal-to-noise ratios, the reinforcement ratio has a dominant effect on surface roughness parameters (Ra and Rz), the coefficient of friction and the weight loss in different levels. In addition, 100/0 reinforced GGG40/CuSn10 gives minimum surface roughness, pure cast iron provides the best weight loss and pure bronze offers the desired coefficient of friction. The results showed the importance of material ingredients on mechanical properties by comparing a wide range of samples from starting the production phase, which provides a perspective for manufacturers to meet the market supply as per human requirements.

Lightweight alloys made from aluminium are used to manufacture cars, trains and planes. The main parts most often manufactured from thin sheets requiring the use of milling in the manufacturing process are front panels for control systems, housing parts for electrical and electronic components. As a result of the final phase of the manufacturing process, cold rolling, residual stresses remain in the surface layers, which can influence the cutting processes carried out on these materials. The main aim of this study was to verify whether the strategy of removing the outer material layers of aluminium alloy sheets affects the surface roughness after the face milling process. EN AW-6082-T6 aluminium alloy thin plates with three different thicknesses and with two directions relative to the cold rolling process direction (longitudinal and transverse) were analysed. Three different strategies for removing the outer layers of the material by face milling were considered. Noticeable differences in surface roughness 2D and 3D parameters were found among all machining strategies and for both rolling directions, but these differences were not statistically significant. The lowest values of Ra = 0.34 µm were measured for the S#3 strategy, which asymmetrically removed material from both sides of the plate (main and back), for an 8-mm-thick plate in the transverse rolling direction. The highest values of Ra = 0.48 µm were measured for a 6-mm-thick plate milled with the S#2 strategy, which symmetrically removed material from both sides of the plate, in the longitudinal rolling direction. However, the position of the face cutter axis during the machining process was observed to have a significant effect on the surface roughness. A higher surface roughness was measured in the areas of the tool point transition from the up-milling direction to the down-milling direction (tool axis path) for all analysed strategies (Ra = 0.63–0.68 µm). The best values were obtained for the up-milling direction, but in the area of the smooth execution of the process (Ra = 0.26–0.29 µm), not in the area of the blade entry into the material. A similar relationship was obtained for analysed medians of the arithmetic mean height (Sa) and the root-mean-square height (Sq). However, in the case of the S#3 strategy, the spreads of results were the lowest.

In this study, the burr and slot widths formed after the micro-milling process of Inconel 718 alloy were investigated using a rapid and accurate image processing method. The measurements were obtained using a user-defined subroutine for image processing. To determine the accuracy of the developed imaging process technique, the automated measurement results were compared against results measured using a manual measurement method. For the cutting experiments, Inconel 718 alloy was machined using several cutting tools with different geometry, such as the helix angle, axial rake angle, and number of cutting edges. The images of the burr and slots were captured using a scanning electron microscope (SEM). The captured images were processed with computer vision software, which was written in C++ programming language and open-sourced computer library (Open CV). According to the results, it was determined that there is a good correlation between automated and manual measurements of slot and burr widths. The accuracy of the proposed method is above 91%, 98%, and 99% for up milling, down milling, and slot measurements, respectively. The conducted study offers a user-friendly, fast, and accurate solution using computer vision (CV) technology by requiring only one SEM image as input to characterize slot and burr formation.

Aluminum alloys are soft and have low melting temperatures, therefore, machining them often results in cut material fusing to the cutting tool due to heat and friction, and thus lowering the hole quality. A good practice is to use coated cutting tools to overcome such issues and maintain good hole quality. Therefore, the current study investigates the effect of cutting parameters (spindle speed and feed rate) and three types of cutting-tool coating (TiN/TiAlN, TiAlN, and TiN) on the surface finish, form, and dimensional tolerances of holes drilled in Al6061-T651 alloy. The study employed statistical design of experiments and ANOVA (analysis of variance) to evaluate the contribution of each of the input parameters on the measured hole-quality outputs (surface-roughness metrics Ra and Rz, hole size, circularity, perpendicularity, and cylindricity). The highest surface roughness occurred when using TiN-coated tools. All holes in this study were oversized regardless of the tool coating or cutting parameters used. TiN tools, which have a lower coating hardness, gave lower hole circularity at the entry and higher cylindricity, while TiN/TiAlN and TiAlN seemed to be more effective in reducing hole particularity when drilling at higher spindle speeds. Finally, optical microscopes revealed that a built-up edge and adhesions were most likely to form on TiN-coated tools due to TiN’s chemical affinity and low oxidation temperature compared to the TiN/TiAlN and TiAlN coatings.

This paper presents the research results of one of the main technological parameters of belt grinding, i.e., the cutting speed while machining corrosion- and heat-resistant, structural carbon and structural alloy steels, aluminum, and heat-resistant nickel alloys. Experimental and analytical methods are used to establish the dependence of the output parameters of surface belt grinding on the cutting speed and tool characteristics. An analytical model, considering the physical and mechanical properties of the grinding belt (strength depending on the base and bond, the thermal conductivity, the type of grinding operation) and the machined material, is created to determine the belt grinding speed. The output parameters, such as the arithmetic mean of the surface roughness (Ra) and the material removal rate (MRR) during the belt grinding of steels, heat-resistant and light alloys, have been studied. Based on the empirical dependencies of the belt grinding parameters, the model was developed for the selection and setting of the cutting speed of belt grinding for the aforementioned alloys, taking into account the type of operation, the type of the machined material, and the main characteristics of the sanding belt.

The features of composite materials such as production flexibility, lightness, and excellent strength put them in the class of materials that attract attention in various critical areas, i.e., aerospace, defense, automotive, and shipbuilding. However, the machining of composite materials displays challenges due to the difficulty in obtaining structural integrity. In this study, Cu/Mo-SiCP composite materials were produced by powder metallurgy with varied reinforcement ratios and then their machinability was investigated. In machinability experiments, the process parameters were selected as cutting speed (vC), feed rate (f), depth of cut (aP), and reinforcement ratio (RR). Two levels of these parameters were taken as per the Taguchi’s L8 orthogonal array, and response surface methodology (RSM) is employed for parametric optimization. As a result, the outcomes demonstrated that RR = 5%, f = 0.25 mm/rev, aP = 0.25 mm, vC = 200 m/min for surface roughness, RR = 0%, f = 0.25 mm/rev and aP = 0.25 mm and vC = 200 m/min for flank wear and RR = 0%, f = 0.25 mm/rev, aP = 0.25 mm, vC = 150 m/min for cutting temperature for cutting temperature and flank wear should be selected for the desired results. In addition, ANOVA results indicate that reinforcement ratio is the dominant factor on all response parameters. Microscope images showed that the prominent failure modes on the cutting tool are flank wear, built up edge, and crater wear depending on reinforcement ratio.

Pure Zn (Zinc) and its Zn–WO3 (Zinc–Tungsten trioxide) composite coatings were deposited on mild steel specimens by applying the electrodeposition technique. Zn–WO3 composites were prepared for the concentration of 0.5 and 1.0 g/L of particles. The influence of WO3 particles on Zn deposition, the surface morphology of composite, and texture co-efficient were analyzed using a variety of techniques, such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) with Energy Dispersive X-ray analysis (EDX). Higher corrosion resistance and microhardness were observed on the Zn–WO3 composite (concentration of 1.0 g/L). The higher corrosion resistance and microhardness of 1.0 g/L Zn–WO3 nanocomposite coatings effectively protect the steel used for the manufacture of products, parts, or systems from chemical or electrochemical deterioration in industrial and marine ambient environments.

Lightweight materials are finding plentiful applications in various engineering sectors due to their high strength-to-weight ratios. Hole-making is an inevitable requirement for their structural applications, which is often marred by thermal damages of the drill causing unacceptable shortening of tool life. Efficient cooling of the tool is a prime requirement for enhancing the process viability. The current work presents a novel technique of cooling only the twist drill between drilling of holes with no effect of the applied cryogenic coolant transferred to the work material. The technique is applied in the drilling of two commonly used high-strength lightweight materials: carbon fibers reinforced polymer (CFRP) and an alloy of titanium (Ti-6Al-4V). The efficacy of the cooling approach is compared with those of conventionally applied continuous cryogenic cooling and no-cooling. The effectiveness is quantified in terms of tool wear, thrust force, hole quality, specific cutting energy, productivity, and consumption of the cryogenic fluid. The experimental work leads to a finding that between-the-holes cryogenic cooling possesses a rich potential in curbing tool wear, reducing thrust force and specific energy consumption, and improving hole quality in drilling of CFRP. Regarding the titanium alloy, it yields a much better surface finish and lesser consumption of specific cutting energy.

The necessity to progress towards sustainability has inspired modern researchers to examine the lubrication and cooling effects of vegetable oils on conventional metal cutting operations. Consequently, as an eco-friendly vegetable product, castor oil can be the right choice as Minimum quantity lubrication (MQL) base fluid. Nonetheless, the high viscosity of castor oil limits its flowability and restricts its industrial application. Conversely, palm oil possesses superior lubricity, as well as flowability characteristics. Hence, an attempt has been made to improve the lubrication behavior of castor oil. Here, six castor-palm mixtures (varying from 1:0.5&ndash, 1:3) were utilized as MQL-fluid, and the values of machining responses viz. average surface roughness, specific cutting energy, and tool wear were evaluated. Furthermore, an integrated Shannon&rsquo, s Entropy-based Technique for order preference by similarity to ideal solution (TOPSIS) framework was employed for selecting the most suitable volume ratio of castor-palm oil mixture. The rank provided by the TOPSIS method confirmed that 1:2 was the best volume ratio for castor-palm oil mixture. Afterward, a comparative analysis demonstrated that the best castor-palm volume fraction resulted in 8.262 and 16.146% lowering of surface roughness, 5.459 and 7.971% decrement of specific cutting energy, 2.445 and 3.155% drop in tool wear compared to that of castor and palm oil medium, respectively.

In the modern fish processing industry, flat fishes play an important role. They are processed into a final product in the form of a fillet during the skinning operation, which is carried out on machines operating in automated production lines. These machines are usually equipped with a single planar cutting blade or a few of such blades. The high-efficiency skinning and industrial conditions cause rapid wear of the cutting edge of the blade, which is detrimental to the quality of the final product. One of the forms of renewing the cutting ability of these types of tools is the regeneration carried out with the use of precise traverse surface grinding. The results of this process must be carefully verified for determining its correctness and possible optimization of its parameters. The main goal of this article was to characterize the usefulness of a number of observational and measuring methods to evaluate the results of the technical blade regeneration process. In this work, a number of contemporary observation&ndash, measurement methods such as optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), optical profilometry (OP), and angle-resolved scattering (ARS), supported by image processing and analysis techniques, were analyzed. The authors focused on presenting the role of the abovementioned methods in the surface characterization of planar cutting blades made of X39Cr13 chromium martensitic stainless steel before and after the technological operation of flat-fish skinning. Additionally, the surface condition after the regeneration process carried out using the five-axis CNC (computerized numerical control) grinding machine was also assessed. Numerous results of surface observations, elemental composition microanalysis, high-accuracy surface microgeometry measurements, and quantitative and qualitative analysis confirming the possibility of using the proposed methods in the presented applications are presented.

The article shows that noncontact measurement techniques can be an important support to X-ray-based methods when examining the surface condition of modern circulated coins. The forms and degrees of wear of such coins, affecting their utility values, qualifying them as a legal tender in a given country, can be measured and analyzed, among other things, using advanced high-accuracy optical profilometry methods. The authors presented four analyses carried out for reverses and obverses of round coins (1 zloty, 1 franc, 50 bani, 5 pens) characterized by different degrees of surface wear. All of the coins were measured using 3D optical profilometers (Talysurf CLI 2000 and S neox) representing two generations of these types of systems. The obtained results confirm the validity of the applied high-accuracy measurement systems in conjunction with dedicated software in the presented applications. Examples of the analyses carried out can be a significant source of information on the condition of coins in the context of maintaining their functional properties (selection of appropriate wear&ndash, resistant alloys and correctness of the production process).

The purpose of the research was to obtain an arc welded joint of a preliminary quenched high-carbon wear resistant steel without losing the structure that is previously obtained by heat treatment. 120Mn3Si2 steel was chosen for experiments due to its good resistance to mechanical wear. The fast cooling of welding joints in water was carried out right after welding. The major conclusion is that the soft austenitic layer appears in the vicinity of the fusion line as a result of the fast cooling of the welding joint. The microstructure of the heat affected zone of quenched 120Mn3Si2 steel after welding with rapid cooling in water consists of several subzones. The first one is a purely austenitic subzone, followed by austenite + martensite microstructure, and finally, an almost fully martensitic subzone. The rest of the heat affected zone is tempered material that is heated during welding below A1 critical temperature. ISO 4136 tensile tests were carried out for the welded joints of 120Mn3Si2 steel and 09Mn2Si low carbon steel (ASTM A516, DIN13Mn6 equivalent) after welding with fast cooling in water. The tests showed that welded joints are stronger than the quenched 120Mn3Si2 steel itself. The results of work can be used in industries where the severe mechanical wear of machine parts is a challenge.

This article presents a methodology for designing belt grinding operations with grinding and lapping machines. It provides the results of a study on the machinability of various steels and alloys with belt grinding, which are then classified according to an indicator that we have developed. Namely, cast aluminum alloys, structural alloy steels, structural carbon steels, corrosion-resistant and heat-resistant stainless steels, and heat-resistant nickel alloys have been investigated. The machinability index is the ratio of the performance indicators of the grinding belt and the depth of cut to the indicators of grade 45 structural carbon steels (similar to steel AISI 1045) and similar steels and alloys. The performance indicators of the grinding belt are chosen from a set of calculated and estimated indicators. Experimentally determining the dependences of the performance indicators on the belt grinding modes and conditions, taking into account the established levels of machinability, allowed us to develop recommendations for designing belt grinding operations with grinding and lapping machines. The proposed methodology for designing belt grinding operations guarantees optimal performance and ensures that the necessary quality of the machinable surfaces is achieved. At the same time, it takes into account variable machining conditions, which change within specified limits.

Fused filament fabrication (FFF), a portable, clean, low cost and flexible 3D printing technique, finds enormous applications in different sectors. The process has the ability to create ready to use tailor-made products within a few hours, and acrylonitrile butadiene styrene (ABS) is extensively employed in FFF due to high impact resistance and toughness. However, this technology has certain inherent process limitations, such as poor mechanical strength and surface finish, which can be improved by optimizing the process parameters. As the results of optimization studies primarily depend upon the efficiency of the mathematical tools, in this work, an attempt is made to investigate a novel optimization tool. This paper illustrates an optimization study of process parameters of FFF using neural network algorithm (NNA) based optimization to determine the tensile strength, flexural strength and impact strength of ABS parts. The study also compares the efficacy of NNA over conventional optimization tools. The advanced optimization successfully optimizes the process parameters of FFF and predicts maximum mechanical properties at the suggested parameter settings.

The main innovation of this article is the determination of the impact of curvature of a shape cut out in a brittle material using an abrasive water jet (AWJ) process as an important factor of the machined surfaces. The curvature of a shape, resulting from the size of the radius of the cutting head trajectory, is one of the key requirements necessary for ensuring the required surface quality of materials shaped by the abrasive water jet process, but very few studies have been carried out in this regard. An important goal of the experimental studies carried out here and presented in this work was to determine its influence on the quality of the inner and outer surfaces of the cutting kerf. This goal was accomplished by cutting the shape of a spiral in soda&ndash, lime glass. For such a shape, the effect of radius of the trajectory of the cutting head on selected parameters of the surface texture of the inner surface of the cutting kerf (IS) and the outer surface of the cutting kerf (OS) was studied. The obtained results of the experimental studies confirmed that the effect of the curvature of the cut shape is important from the point of view of the efficiency of the glass-based brittle material-cutting process using AWJ. Analyses of the surface textures of the areas located in the upper part of the inner and outer surfaces separated by the use of AWJ machining showed that the OS surfaces are characterized by worse technological quality compared with IS surfaces. Differences in the total height of surface irregularities (given by St amplitude parameter), determined on the basis of the obtained results of the measurements of both surfaces of the cutting kerf, were as follows: &Delta, Str = 50 = 0.6 &mu, m, &Delta, Str = 35 = 1 &mu, Str = 15 = 1.3 &mu, m. The analysis of values measured in areas located in the more sensitive zone of influence of the AWJ outflow proved that the total height of irregularities (St) of the OS was higher. Differences in the total heights of irregularities for inner and outer surfaces of the cutting kerf were as follows: &Delta, Str = 50 = 2.1 &mu, Str = 35 = 3 &mu, Str = 15 = 14.1 &mu, m, respectively. The maximum difference in the total heights of irregularities (St), existing between the surfaces considered in a special case (radius 15 mm), was almost 20%, which should be a sufficient condition for planning cutting operations, so as to ensure the workpiece is shaped mainly by internal surfaces.

AISI 5140 is a steel alloy used for manufacturing parts of medium speed and medium load such as gears and shafts mainly used in automotive applications. Parts made from AISI 5140 steel require machining processes such as turning and milling to achieve the final part shape. Limited research has been reported on the machining vibration and surface roughness during turning of AISI 5140 in the open literature. Therefore, the main aim of this paper is to conduct a systematic study to determine the optimum cutting conditions, analysis of vibration and surface roughness under different cutting speeds, feed rates and cutting edge angles using response surface methodology (RSM). Prediction models were developed and optimum turning parameters were obtained for averaged surface roughness (Ra) and three components of vibration (axial, radial and tangential) using RSM. The results demonstrated that the feed rate was the most affecting parameter in increasing the surface roughness (69.4%) and axial vibration (65.8%) while cutting edge angle and cutting speed were dominant on radial vibration (75.5%) and tangential vibration (64.7%), respectively. In order to obtain minimum vibration for all components and surface roughness, the optimum parameters were determined as Vc = 190 m/min, f = 0.06 mm/rev, &kappa, = 60&deg, with high reliability (composite desirability = 90.5%). A good agreement between predicted and measured values was obtained with the developed model to predict surface roughness and vibration during turning of AISI 5140 within a 10% error range.

Optimization of tool life is required to tune the machining parameters and achieve the desired surface roughness of the machined components in a wide range of engineering applications. There are many machining input variables which can influence surface roughness and tool life during any machining process, such as cutting speed, feed rate and depth of cut. These parameters can be optimized to reduce surface roughness and increase tool life. The present study investigates the optimization of five different sensorial criteria, additional to tool wear (VB) and surface roughness (Ra), via the Tool Condition Monitoring System (TCMS) for the first time in the open literature. Based on the Taguchi L9 orthogonal design principle, the basic machining parameters cutting speed (vc), feed rate (f) and depth of cut (ap) were adopted for the turning of AISI 5140 steel. For this purpose, an optimization approach was used implementing five different sensors, namely dynamometer, vibration, AE (Acoustic Emission), temperature and motor current sensors, to a lathe. In this context, VB, Ra and sensorial data were evaluated to observe the effects of machining parameters. After that, an RSM (Response Surface Methodology)-based optimization approach was applied to the measured variables. Cutting force (97.8%) represented the most reliable sensor data, followed by the AE (95.7%), temperature (92.9%), vibration (81.3%) and current (74.6%) sensors, respectively. RSM provided the optimum cutting conditions (at vc = 150 m/min, f = 0.09 mm/rev, ap = 1 mm) to obtain the best results for VB, Ra and the sensorial data, with a high success rate (82.5%).

The mechanical, physical and interfacial properties of aluminum alloys are improved by reinforcing the silicon carbide particles (SiCp). Machinability of such alloys by traditional methods is challenging due to higher tool wear and surface roughness. The objective of research is to investigate the machinability of SiCp reinforced Al6061 composite by Wire-Electrical Discharge Machining (wire-EDM). The effect of wire-EDM parameters namely current (I), pulse-on time (Ton), wire-speed (Ws), voltage (Iv) and pulse-off time (Toff) on material removal rate (MRR) is investigated and their settings are optimized for achieving the high MRR. The experiments are designed by using Taguchi L16 orthogonal arrays. The MRR obtained at different experiments are analyzed using statistical tools. It is observed that all the chosen process parameters showed significant influence of on the MRR with contribution of 27.39%, 22.08%, 21.32%, 15.76% and 12.94% by I, Iv, Toff, Ton and Ws, respectively. At optimum settings, the Wire-EDM resulted in MRR of 65.21 mg/min and 62.41 mg/min for samples with 4% and 8% SiCp. The results also indicated reinforcing SiCp upto 8% showed marginally low influence on MRR. Microstructural investigation of the cut surface revealed the presence of craters with wave pattern on its surface. The top surface of the crater is featured by the recast layers connecting adjacent craters. Further, the statistical model is developed using linear regression to predict the MRR (?2—73.65%) and its predicting accuracy is verified by the confirmation trials. The statistical model is useful for predicting the MRR for different settings of the process parameters. The optimized settings can be used to improve the machining productivity by increasing the MRR while machining of Al6061-SiCp (upto 8 wt. %) alloy by wire-EDM industries.

Powder metallurgy (PM) method is one of the most effective methods for the production of composite materials. However, there are obstacles that limit the production of magnesium matrix composites (MgMCs), which are in the category of biodegradable materials, by this method. During the weighing and mixing stages, risky situations can arise, such as the exposure of Mg powders to oxidation. Once this risk is eliminated, new MgMCs can be produced. In this study, a paraffin coating technique was applied to Mg powders and new MgMCs with superior mechanical and corrosion properties were produced using the hot pressing technique. The content of the composites consist of an Mg2Zn matrix alloy and Al2O3 particle reinforcements. After the debinding stage at 300 °C, the sintering process was carried out at 625 °C under 50 MPa pressure for 60 min. Before and after the immersion process in Hank’s solution, the surface morphology of the composite specimens was examined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis. With the hot pressing technique, composite specimens with a very dense and homogeneous microstructure were obtained. While Al2O3 reinforcement improved the mechanical properties, it was effective in changing the corrosion properties up to a certain extent (2 wt.% Al2O3). The highest tensile strength value of approximately 191 MPa from the specimen with 8 wt.% Al2O3. The lowest weight loss and corrosion rate were obtained from the specimen containing 2 wt.% Al2O3 at approximately 9% and 2.5 mm/year, respectively. While the Mg(OH)2 structure in the microstructure formed a temporary film layer, the apatite structures containing Ca, P, and O exhibited a permanent behavior on the surface, and significantly improved the corrosion resistance.

Despite extensive knowledge of the cutting methods described, no universal method has been developed so far for evaluating the technological quality of elements shaped by different cutting processes. The aim of the research described in this article was to fill this gap and to propose the author’s methodology for the assessment of the technological quality of the surface of X5CRNI18-10 steel shaped as a result of laser cutting and abrasive water jet cutting. A synthetic index of technological quality assessment of the surface after cutting CTQ (cutting technological quality) was proposed. Three groups of factors were taken into account in the assessment of technological quality of the surface after cutting: selected surface texture parameters (arithmetic mean deviation of the surface Sa and total height of the surface St), results of measurements of dimensional accuracy of cut elements (length deviation LD and width deviation WD) as well as indicators of surface morphology estimated on the basis of microscopic images of the surface after cutting (deformation intensity DI and identification of cutting zones ICZ). On the basis of CTQ values determined, the cutting results of both cutting methods were compared. The analyses presented in this paper proved that the CTQ index can be effectively used to compare the results of a cutting process conducted using different methods and under different conditions. The developed CTQ index is a universal valuation tool, allowing for quantitative evaluation of features related to the technological quality of cutting process results.

The prevalence of micro-holes is widespread in mechanical, electronic, optical, ornaments, micro-fluidic devices, etc. However, monitoring and detection tool wear and tool breakage are imperative to achieve improved hole quality and high productivity in micro-drilling. The various multi-sensor signals are used to monitor the condition of the tool. In this work, the vibration signals and cutting force signals have been applied individually as well as in combination to determine their effectiveness for tool-condition monitoring applications. Moreover, they have been used to determine the best strategies for tool-condition monitoring by prediction of hole quality during micro-drilling operations with 0.4 mm micro-drills. Furthermore, this work also developed an adaptive neuro fuzzy inference system (ANFIS) model using different time domains and wavelet packet features of these sensor signals for the prediction of the hole quality. The best prediction of hole quality was obtained by a combination of different sensor features in wavelet domain of vibration signal. The model&rsquo, s predicted results were found to exert a good agreement with the experimental results.

Environmental protection is the major concern of any form of manufacturing industry today. As focus has shifted towards sustainable cooling strategies, minimum quantity lubrication (MQL) has proven its usefulness. The current survey intends to make the MQL strategy more effective while improving its performance. A Ranque–Hilsch vortex tube (RHVT) was implemented into the MQL process in order to enhance the performance of the manufacturing process. The RHVT is a device that allows for separating the hot and cold air within the compressed air flows that come tangentially into the vortex chamber through the inlet nozzles. Turning tests with a unique combination of cooling technique were performed on titanium (Grade 2), where the effectiveness of the RHVT was evaluated. The surface quality measurements, forces values, and tool wear were carefully investigated. A combination of analysis of variance (ANOVA) and evolutionary techniques (particle swarm optimization (PSO), bacteria foraging optimization (BFO), and teaching learning-based optimization (TLBO)) was brought into use in order to analyze the influence of the process parameters. In the end, an appropriate correlation between PSO, BFO, and TLBO was investigated. It was shown that RHVT improved the results by nearly 15% for all of the responses, while the TLBO technique was found to be the best optimization technique, with an average time of 1.09 s and a success rate of 90%.

In the present research, a composite layer of TiO2-TiC-NbO-NbC was coated on the Ti-64 alloy using two different methods (i.e., the electric discharge coating (EDC) and electric discharge machining processes) while the Nb powder were mixed in dielectric fluid. The effect produced on the machined surfaces by both processes was reported. The influence of Nb-concentration along with the EDC key parameters (Ip and Ton) on the coated surface integrity such as surface topography, micro-cracks, coating layer thickness, coating deposition, micro-hardness has been evaluated as well. It has been noticed that in the EDC process the high peak current and high Nb-powder concentration allow improvement in the material migration, and a crack-free thick layer (215 &mu, m) on the workpiece surface is deposited. The presence of various oxides and carbides on the coated surface further enhanced the mechanical properties, especially, the wear resistance, corrosion resistance and bioactivity. The surface hardness of the coated layer is increased from 365 HV to 1465 HV. Furthermore, the coated layer reveals a higher adhesion strength (~118 N), which permits to enhance the wear resistance of the Ti-64 alloy. This proposed technology allows modification of the mechanical properties and surface characteristics according to an orthopedic implant&rsquo, s requirements.

Now-a-days, the application of hard tuning with CBN tool has been massively increased because the hard turning is a good alternative to grinding process. However, there are some issues that need to be addressed related to the CBN grades and their particular applications in the area of hard turning process. This experimental study investigated the effects of three different grades of CBN insert on the cutting forces and surface roughness. The process of hard turning was made using the AISI H13 die tool steel at containing different hardness (45 HRC, 50 HRC and 55 HRC) levels. The work material were selected on the basis of its application in the die making industries in a range of hardness of 45&ndash, 55 HRC. Optimization by the central composite design approach has been used for design and analysis. The present study reported that the cutting forces and surface roughness are influenced by the alloying elements and percentage of CBN in the cutting tool material. The work material hardness, feed rate and cutting speed are found to be statistically significant on the responses. Furthermore, a comparative performance between the three different grades of CBN inserts has been shown on the cutting forces and surface roughness at different workpiece hardness. To obtain the optimum parameters from multiple responses, desirability approach has been used. The novelty/robustness of the present study is represented by its great contribution to solve practical industrial application when is developed a new process using different CBN grades for hard turning and die makers of workpiece having the hardness between 45 and 55 HRC.

Extrusion-based three-dimensional (3D) printing methods are preferred and emerging approaches for freely digital fabrication of ceramics due to ease of use, low investment, high utilization of materials, and good adaptability to multi-materials. However, systematic knowledge still lacks an explanation for what is their 3D printability. Moreover, some uncontrollable factors including extrudate shape retention and nonuniform drying inevitably limit their industrial applications. The purpose of this research was to present a new shaping retention method based on mathematical synthesis modeling for extrusion-based 3D-printing of ceramic pastes. Firstly, the steady-state equilibrium equation of the extrusion process was derived to provide clearer theoretical indications than purely experimental methods. Furthermore, a mathematical description framework was synthesized to better understand the extrusion-based 3D-printing of ceramic pastes from several realms: pastes rheology, extrudability, shape-holdability, and drying kinetics. Secondly, for eliminating shaping drawbacks (e.g., deformation and cracks) originating from non-digital control factors, we put forward a digital shape-retention technology inspired by the generalized drying kinetics of porous materials, which was different from existing retention solutions, e.g., freezing retention, thermally induced gelation, and using removable support structures. In addition, we developed an in situ hot air flow drying device easily attached to the nozzle of existing 3D printers. Confirmatory 3D-printing experiments of thin-walled cone-shape benchmark parts and the fire arrowhead-like object clearly demonstrated that the presented shape-retention method not only upgraded layer-by-layer forming capability but also enabled digital control of extrudate solidification. In addition, many more experimental results statistically showed that both fully solid parts and purely thin-wall parts had higher dimensional accuracy and better surface quality than the offline drying method. The 3D printed ceramic products with complex profiled surfaces conceivably demonstrated that our improved extrusion-based 3D-printing process of ceramic pastes has game-changing potentials beyond the traditional craftsmanship capacity.

In the literature, there are a small number of publications regarding the construction and application of machine tools that integrate several machining operations. Additionally, solutions that allow for such integration for complex operations, such as the machining of shape surfaces with complex contours, are relatively rare. The authors of this article carried out dimensional analysis of workpieces machined using a prototype Computerized Numerical Control (CNC) machine tool that integrates the possibilities of 3D scanning, milling operations in three axes, and grinding operations using abrasive discs. The general description of this machine tool with developed methodology and the most interesting results obtained during the experimental studies are given. For a comparative analysis of the influence of the machining method on the geometric accuracy of the test pieces, an Analysis of Variance (ANOVA) was carried out. The obtained results show that for four considered features (deviations of flatness, vertical parallelism, opening dimensions, and opening cylindricality), no statistically significant differences were detected. For the evaluation criteria, the probability level p exceeded the assumed confidence level &alpha, = 0.05 and ranged from p = 0.737167 to p = 0.076764. However, such differences were found for two others&mdash, a dimensional deviation between flat surfaces (p = 0.010467) and horizontal parallelism deviation (p = 0.0)&mdash, as well as for the quality of the machined surface defined by four surface texture parameters: Ra (p = 0.831797), Rt (p = 0.759636), Rq (p = 0.867222), and Rz (p = 0.651896). The information obtained by the ANOVA will be useful for the elimination the weaknesses of the prototype machine tool, further analysis of technological strategies, and to find possible benefits of integrating machining operations.

Despite several additive manufacturing techniques are commercially available in market, Fused Deposition Modeling (FDM) is increasingly used by researchers and engineers for new product development. FDM is an established process with a plethora of advantages, but the visible surface roughness (SR), being an intrinsic limitation, is major barrier against utilization of fabricated parts for practical applications. In the present study, the chemical finishing method, using vapour of acetone mixed with heated air, is being used. The combined impact of orientation angle, finishing temperature and finishing time has been studied using Taguchi and ANOVA, whereas multi-criteria optimization is performed using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The surface finish was highly responsive to increase in temperature while orientation angle of 0&deg, yielded maximum strength, increase in finishing time led to weight gain of FDM parts. As the temperature increases, the percentage change in surface roughness increases as higher temperature assists the melt down process. On the other hand, anisotropic behaviour plays a major role during tensile testing. The Signal-to-noise (S/N) ratio plots, and ANOVA results indicated that surface finish is directly proportionate to finishing time because a longer exposure results in complete layer reflowing and settlement.

In the present study, the machinability indices of surface grinding of AISI D2 steel under dry, flood cooling, and minimum quantity lubrication (MQL) conditions are compared. The comparison was confined within three responses, namely, the surface quality, surface temperature, and normal force. For deeper insight, the surface topography of MQL-assisted ground surface was analyzed too. Furthermore, the statistical analysis of variance (ANOVA) was employed to extract the major influencing factors on the above-mentioned responses. Apart from this, the multi-objective optimization by Grey–Taguchi method was performed to suggest the best parameter settings for system-wide optimal performance. The central composite experimental design plan was adopted to orient the inputs wherein the inclusion of MQL flow rate as an input adds addition novelty to this study. The mathematical models were formulated using Response Surface Methodology (RSM). It was found that the developed models are statistically significant, with optimum conditions of depth of cut of 15 µm, table speed of 3 m/min, cutting speed 25 m/min, and MQL flow rate 250 mL/h. It was also found that MQL outperformed the dry as well as wet condition in surface grinding due to its effective penetration ability and improved heat dissipation property.

Magnesium alloys are widely used in aerospace vehicles and modern cars, due to their rapid machinability at high cutting speeds. A novel Edgeworth–Pareto optimization of an artificial neural network (ANN) is presented in this paper for surface roughness (Ra) prediction of one component in computer numerical control (CNC) turning over minimal machining time (Tm) and at prime machining costs (C). An ANN is built in the Matlab programming environment, based on a 4-12-3 multi-layer perceptron (MLP), to predict Ra, Tm, and C, in relation to cutting speed, vc, depth of cut, ap, and feed per revolution, fr. For the first time, a profile of an AZ61 alloy workpiece after finish turning is constructed using an ANN for the range of experimental values vc, ap, and fr. The global minimum length of a three-dimensional estimation vector was defined with the following coordinates: Ra = 0.087 μm, Tm = 0.358 min/cm3, C = $8.2973. Likewise, the corresponding finish-turning parameters were also estimated: cutting speed vc = 250 m/min, cutting depth ap = 1.0 mm, and feed per revolution fr = 0.08 mm/rev. The ANN model achieved a reliable prediction accuracy of ±1.35% for surface roughness.