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Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace

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A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Manufacturing Processes and Systems".

Deadline for manuscript submissions: closed (20 July 2022) | Viewed by 37395

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Prof. Dr. Luis Norberto López De Lacalle

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The Aeronautics Advanced Manufacturing Center-CFAA, 48170 Zamudio, Biscay, Spain
Interests: manufacturing process
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. Naiara Ortega

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Metrology lab CFAA; Department of Mechanical Engineering, University of the Basque Country; EIB, Alameda de Urquijo s/n, 48013 Bilbao, Spain
Interests: metrology; NDTs; welding; coatings; machining; manufacturing of aeroengine components; vibrations in manufacturing processes
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Dr. Joseba Albizuri

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Department of Mechanical Engineering, University of the Basque Country; EIB, Alameda de Urquijo s/n, 48013 Bilbao, Spain
Interests: machining of superalloys; additive manufacturing; welding; coatings; machining; manufacturing of aeroengine components; vibrations in manufacturing processes
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Aeronautics is moving fast for achieving the general goals of a reduction in fuel consumption, a reduction of CO₂ and NO_x emissions by 30%, and a dramatic reduction in noise. The so-called NEO airplanes are now flying overs us; NEO stands for new engine option. There are also new aircrafts launched in Japan and China, as well as variations in the main airliner’s manufacturers.

Materials, both for fuselage and engines, are key, but all machine-tools, cutting tools, additive manufacturing, and production equipment are of paramount importance as well. To improve production by two, in order to be able to accomplish the huge demand of new planes, new materials, new processes, and new approaches are key.

Additive manufacturing is also a new player in the field, involving new alloys in powder, machines, and applications. However, machining, drilling, and grinding are, and still will be, the practical solution for achieving both productivity and tight tolerances.

On the other hand, the early detection of materials defects, nondestructive inspection, and metrology are the basic elements to keep safety as close to being absolute reliability. Mechanical testing, fatigue experimentation, and other fields are key as well.

Papers about composites, special alloys, primary and secondary processes, and other manufacturing concepts related with aeronautics and aerospace will be considered.

Prof. Dr. Luis Norberto López de Lacalle
Prof. Dr. Naiara Ortega
Dr. Joseba Albizuri
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Machining of superalloys
Drilling, riveting, and assembly of composites and aerostructures
Composites CFRP
Laser-additive manufacturing
Abrasive machining and finishing
New emerging alloys: Gamma Ti–Al processing
Machinability
Surface integrity
Modeling of machining and grinding processes
Integral blade rotors: the challenge
Cutting tools for the group ISO S-alloys
Special processes for emerging materials
Testing of materials: fatigue and electrochemical performance
Health monitoring

Published Papers (14 papers)

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Research

18 pages, 6385 KiB

Open AccessArticle

Structural Potting of Large Aeronautic Honeycomb Panels: End-Effector Design and Test for Automated Manufacturing

by Carlos Campos, Enrique Casarejos and Abraham Segade

Materials 2022, 15(19), 6679; https://0-doi-org.brum.beds.ac.uk/10.3390/ma15196679 - 26 Sep 2022

Cited by 2 | Viewed by 1733

Abstract

Structural potting is used to prepare honeycomb panels to fix metallic elements, typical in aircraft doors. In this paper, a full procedure for structural potting using robotic arms is presented for the first time. Automating this procedure requires the integration of, first, machining operations to remove the skin layers and prepare the potting points and, then, resin injection into the honeycomb cells. The paper describes the design, prototyping, and testing of specific end-effectors. Different end-effectors were explored to ensure efficient injection. The results obtained with the prototypes show that the potting quality is adequate to accomplish the required process checks for industrial manufacturing. The injection process time can be reduced by a factor greater than 3.5, together with the extra assets associated with the automation of complex tasks. Therefore, structural potting automation is demonstrated to be feasible with the end-effectors proposed for milling and injection, which are ready for use with conventional robotic arms in manufacturing lines. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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14 pages, 6514 KiB

Open AccessArticle

Estimation of Drag Finishing Abrasive Effect for Cutting Edge Preparation in Broaching Tool

by Cristian F. Pérez-Salinas, Ander del Olmo and L. Norberto López de Lacalle

Materials 2022, 15(15), 5135; https://0-doi-org.brum.beds.ac.uk/10.3390/ma15155135 - 24 Jul 2022

Cited by 8 | Viewed by 1765

Abstract

In recent years, cutting edge preparation became a topic of high interest in the manufacturing industry because of the important role it plays in the performance of the cutting tool. This paper describes the use of the drag finishing DF cutting edge preparation process on the cutting tool for the broaching process. The main process parameters were manipulated and analyzed, as well as their influence on the cutting edge rounding, material remove rate MRR, and surface quality/roughness (Ra, Rz). In parallel, a repeatability and reproducibility R&R analysis and cutting edge radius r_e prediction were performed using machine learning by an artificial neural network ANN. The results achieved indicate that the influencing factors on r_e, MRR, and roughness, in order of importance, are drag depth, drag time, mixing percentage, and grain size, respectively. The reproducibility accuracy of r_e is reliable compared to traditional processes, such as brushing and blasting. The prediction accuracy of the r_e of preparation with ANN is observed in the low training and prediction errors 1.22% and 0.77%, respectively, evidencing the effectiveness of the algorithm. Finally, it is demonstrated that the DF has reliable feasibility in the application of edge preparation on broaching tools under controlled conditions. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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15 pages, 22734 KiB

Open AccessArticle

Mechanical and Chemical Characterisation of TiN and AlTiSiN Coatings on a LPBF Processed IN718 Substrate

by Juan C. Colombo-Pulgarín, Antonio J. Sánchez Egea, Diego J. Celentano, Daniel Martínez Krahmer, Vitaliy Martynenko and Norberto López de Lacalle

Materials 2021, 14(16), 4626; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14164626 - 17 Aug 2021

Cited by 8 | Viewed by 1713

Abstract

Wear-resistant coatings development is progressively increasing steeply due to their advantages when applied to mechanical components subjected to abrasive and destructive environments. Titanium nitride (TiN) coating is typically used to enlarge tools and components’ service life and improve their surface quality. On the other hand, AlTiSiN coating intends to be applied to more aggressive environments such as spatial satellites components exposed to solar radiation, extremely high temperatures, and random particles impact. In this work, specimens of Inconel 718 (IN718) were fabricated via laser powder bed fusion (LPBF), and physical vapour deposition (PVD)-deposited with TiN and AlTiSiN as coatings to mechanically and chemically characterise their surface. In this respect, microhardness testing and chemical analysis via glow discharge optical emission spectroscopy (GDOES) were performed. Later, roughness and wear behaviour analyses were carried out to evaluate the mechanical performance of both coatings and their surface and morphological features. The experimental observations allowed the analysis of both studied coatings by comparing them with the substrate processed via LPBF. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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21 pages, 9843 KiB

Open AccessEditor’s ChoiceArticle

Laser Beam Drilling of Inconel 718 and Its Effect on Mechanical Properties Determined by Static Uniaxial Tensile Testing at Room and Elevated Temperatures

by Jana Petrů, Marek Pagáč and Martin Grepl

Materials 2021, 14(11), 3052; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14113052 - 03 Jun 2021

Cited by 4 | Viewed by 2217

Abstract

Particularly in the aerospace industry and its applications, recast layers and microcracks in base materials are considered to be undesirable side effects of the laser beam machining process, and can have a significant influence on the resulting material behavior and its properties. The paper deals with the evaluation of the affected areas of the Inconel 718 nickel-base superalloy after its drilling by a laser beam. In addition, measurements and analyses of the mechanical properties were performed to investigate how these material properties were affected. It is supposed that the mechanical properties of the base material will be negatively affected by this accompanying machining process phenomenon. As a verification method of the final mechanical properties of the material, static uniaxial tension tests were performed on experimental flat shape samples made of the same material (Inconel 718) and three different thicknesses (0.5/1.0/1.6 mm) which best represented the practical needs of aerospace sheet metal applications. There was one hole that was drilled with an angle of under 70° in the middle of the sample length. Additionally, there were several sets of samples for each material thickness that were drilled by both conventional and nonconventional methods to emphasize the effect of the recast layer on the base material. In total, 192 samples were evaluated within the experiment. Moreover, different tensile testing temperatures (room as 23 °C and elevated as 550 °C) were determined for all the circumstances of the individual experiments to simulate real operation load material behavior. As a result, the dependencies between the amount of the recast layer and the length of the microcracks observed after the material was machined by laser beam, and the decrease in the mechanical properties of the base material, were determined. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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17 pages, 7513 KiB

Open AccessArticle

Milling Performance of CFRP Composite and Atomised Vegetable Oil as a Function of Fiber Orientation

by Tarek-Shaban-Mohamed Elgnemi, Martin Byung-Guk Jun, Victor Songmene and Agnes Marie Samuel

Materials 2021, 14(8), 2062; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14082062 - 20 Apr 2021

Cited by 6 | Viewed by 2220

Abstract

Carbon fiber reinforced polymers (CFRPs) have found diverse applications in the automotive, space engineering, sporting goods, medical and military sectors. CFRP parts require limited machining such as detouring, milling and drilling to produce the shapes used, or for assembly purposes. Problems encountered while machining CFRP include poor tool performance, dust emission, poor part edge quality and delamination. The use of oil-based metalworking fluid could help improve the machining performance for this composite, but the resulting humidity would deteriorate the structural integrity of the parts. In this work the performance of an oil-in-water emulsion, obtained using ultrasonic atomization but no surfactant, is examined during the milling of CFRP in terms of fiber orientation and milling feed rate. The performance of wet milling is compared with that of a dry milling process. The tool displacement-fiber orientation angles (TFOA) tested are 0°, 30°, 45°, 60°, and 90°. The output responses analyzed were cutting force, delamination, and tool wear. Using atomized vegetable oil helps in significantly reducing the cutting force, tool wear, and fiber delamination as compared to the dry milling condition. The machining performance was also strongly influenced by fiber orientation. The interactions between the fiber orientation, the machining parameters and the tested vegetable oil-based fluid could help in selecting appropriate cutting parameters and thus improve the machined part quality and productivity. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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18 pages, 5719 KiB

Open AccessArticle

Nickel-Based Alloy Dry Milling Process Induced Material Softening Effect

by Jun Zha, Zelong Yuan, Hangcheng Zhang, Yipeng Li and Yaolong Chen

Materials 2020, 13(17), 3758; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13173758 - 25 Aug 2020

Cited by 5 | Viewed by 1724

Abstract

Improving the cutting efficiency is the major factor for improving the processing of nickel-based alloys. The novelty of this research is the calibrated SiAlON ceramic tool dry milling nickel-based alloy process. Firstly, the nickel-based alloy dry milling process was analyzed through the finite element method, and the required milling force and temperature were deduced. Then, several dry milling experiments were conducted with the milling temperature, and the milling force was monitored. The change in cutting speeds was from 400 m/min to 700 m/min. Experimental results verified the reduction of the dry milling force hypothesized by the simulation. The experiment also indicated that with a cut depth of 0.3 mm, cut width of 6 mm, and feed per tooth of 0.03 mm/z, when milling speed exceeded 527.52 m/min, the milling force began to decrease, and the milling temperature exceeded the nickel-based alloy softening temperature. This indicated that easy cutting could be realized under high-speed dry milling conditions. The interpolation curve about average temperature and average milling forces showed similarity to the tensile strength reduction with the rise of temperature. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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23 pages, 18261 KiB

Open AccessArticle

Strength Analysis of a Rib-Stiffened GLARE-Based Thin-Walled Structure

by Andrzej Kubit, Tomasz Trzepieciński, Bogdan Krasowski, Ján Slota and Emil Spišák

Materials 2020, 13(13), 2929; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13132929 - 30 Jun 2020

Cited by 17 | Viewed by 5081

Abstract

This paper presents a new product, a glass laminate aluminium-reinforced epoxy (GLARE)-based thin-walled structure with a stiffener in the form of a longitudinal rib. The stiffening rib in an outer metallic layer of a GLARE-based panel was fabricated by the incremental sheet forming technique and Alclad 2024-T3 aluminium alloy sheets were used as adherends. The strength properties of the adhesive joint between the layers of the fibre metal laminates (FMLs) were determined in a uniaxial tensile test, peel drum test, tensile/shear test and short-beam three-point-bending test. Two variants of FMLs were considered, with an adhesive film and without an adhesive film between the adherends and the epoxy/glass prepreg. The FMLs were tested at three different temperatures that corresponded to those found under real aircraft operating conditions, i.e., −60 °C, room temperature and +80 °C. It was found that the temperatures do not affect the tensile strength and shear strength of the FMLs tested. However, there was a noticeable increase in the stiffness of samples stretched at reduced temperature. An additional adhesive film layer between the adherends and the glass/epoxy prepreg significantly improves the static peeling strength of the joint both at reduced and at elevated temperatures. A clear increase in the critical force at which buckling occurs has been clearly demonstrated in the uniaxial compression test of GLARE-based rib-stiffened panels. In the case of GLARE-based rib-stiffened panels, the critical force averaged 15,370 N, while for the non-embossed variant, it was 11,430 N, which translates into a 34.5% increase in critical force. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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19 pages, 11615 KiB

Open AccessArticle

Modeling and Optimization of Bidirectional Clamping Forces in Drilling of Stacked Aluminum Alloy Plates

by Jintong Liu, Anan Zhao, Piao Wan, Huiyue Dong and Yunbo Bi

Materials 2020, 13(12), 2866; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13122866 - 26 Jun 2020

Cited by 5 | Viewed by 2132

Abstract

Interlayer burrs formation during drilling of stacked plates is a common problem in the field of aircraft assembly. Burrs elimination requires extra deburring operations which is time-consuming and costly. An effective way to inhibit interlayer burrs is to reduce the interlayer gap by preloading clamping force. In this paper, based on the theory of plates and shells, a mathematical model of interlayer gap with bidirectional clamping forces was established. The relationship between the upper and lower clamping forces was investigated when the interlayer gap reaches zero. The optimization of the bidirectional clamping forces was performed to reduce the degree and non-uniformity of the deflections of the stacked plates. Then, the finite element simulation was conducted to verify the mathematical model. Finally, drilling experiments were carried out on 2024-T3 aluminum alloy stacked plates based on the dual-machine-based automatic drilling and riveting system. The experimental results show that the optimized bidirectional clamping forces can significantly reduce the burr heights. The work in this paper enables us to understand the effect of bidirectional clamping forces on the interlayer gap and paves the way for the practical application. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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17 pages, 4501 KiB

Open AccessArticle

Multiple Sensor Monitoring of CFRP Drilling to Define Cutting Parameters Sensitivity on Surface Roughness, Cylindricity and Diameter

by Miguel Álvarez-Alcón, Luis Norberto López de Lacalle and Francisco Fernández-Zacarías

Materials 2020, 13(12), 2796; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13122796 - 21 Jun 2020

Cited by 17 | Viewed by 2409

Abstract

Machining parameters affects the final quality of components made in carbon fiber reinforced plastic (CFRP) composite materials. In this framework, the work here presented aims at studying the right combination of cutting speed (v_c) and feed rate (v_f), for dry drilling of carbon fiber reinforced plastic composite materials, which obtained better results regarding roughness, hole cylindricity, and diameter. A series of experimental tests were carried out under different drilling conditions (v_c/v_f), monitoring the thrust force (Fz), torque (T), and electric power (EP), to define which one can help more for industrial daily life production. Results validation was carried out using the analysis of variance, in order to relate main machining parameters cutting speed and linear feed, with thrust force, drilling torque, main spindle electric power and hole quality parameters (average roughness, cylindricity and diameter). The conclusions show that thrust force is not proportional to the cutting speed and the best combinations of cutting speed and feed were found out around the average values of tested parameters. Spindle electric power is an interesting element to take into account because it is easy to consider in real production. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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15 pages, 3325 KiB

Open AccessArticle

Reliability and Lifetime Assessment of Glider Wing’s Composite Spar through Accelerated Fatigue Life Testing

by Sebastian Marian Zaharia, Mihai Alin Pop and Răzvan Udroiu

Materials 2020, 13(10), 2310; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13102310 - 17 May 2020

Cited by 7 | Viewed by 3340

Abstract

The evaluation of the reliability and the lifetime of aerospace components has become an important segment of the design stage. The aeronautical components are subjected to complex, rigorous tests and have a long test life. The main goal in the field of aviation is to have components with high reliability and quality and to meet the mandatory requirements and regulations. The spars are stiffening components positioned along the wing and which take up most of the load and are tested for fatigue over a long period of time. The spar which was analysed in this study has a sandwich structure with GFRP (glass fiber reinforced plastic) skin and foam core. In this paper, the performances in the static and dynamic conditions of the GFRP-foam sandwich structures cut out of the composite spar of a glider were analysed. Additionally, using accelerated techniques based on the three-point fatigue bending test, the main reliability indicators of the GFRP-foam sandwich structures were determined. Using the statistical processing of the experimental data and the Inverse Power Law–Weibull acceleration model, the mean number of cycles to failure, in normal testing conditions of the GFRP-foam specimens was determined, with a value of 102,814. Using the accelerated testing techniques of the GFRP-foam sandwich structures an important decrease of the test time (8.43 times) was obtained. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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12 pages, 3648 KiB

Open AccessArticle

Large Cutting Depth and Layered Milling of Titanium Alloy Thin-Walled Parts

by Jun Zha, Jianxin Liang, Yipeng Li, Huijie Zhang and Yaolong Chen

Materials 2020, 13(7), 1499; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13071499 - 25 Mar 2020

Cited by 9 | Viewed by 2191

Abstract

Deformation of thin-walled titanium alloys can occur during the milling process due to the cutting force and chatter vibration, which can influence the precision of the finished parts. In this research, a new milling method without auxiliary support for machining of thin-walled parts was proposed. A large cutting depth and layered milling technology were used during rough machining, with a different machining allowance for each subsequent remaining layer. In the finishing stage, the surface of the previous layer needed to be dressed before processing the next layer. A TiAlSiN-coated, cemented carbide milling cutter was used to machine titanium alloy thin-walled parts, which are characterized by continuous multilayers of unequal thickness. The processing path was simulated using HyperMILL software, and the machining accuracy was detected by the 3D optical scanner. The measurement results indicated that the surface contour accuracy of the parts was ±0.21 mm, within a range of ±0.30 mm. The machining efficiency was increased by 40%, while guaranteeing machining accuracy. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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14 pages, 6744 KiB

Open AccessArticle

Machining Stresses and Initial Geometry on Bulk Residual Stresses Characterization by On-Machine Layer Removal

by Maria Aurrekoetxea, Luis Norberto López de Lacalle and Iñigo Llanos

Materials 2020, 13(6), 1445; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13061445 - 22 Mar 2020

Cited by 26 | Viewed by 2984

Abstract

Prediction and control of machining distortion is a primary concern when manufacturing monolithic components due to the high scrap and rework costs involved. Bulk residual stresses, which vary from blank to blank, are a major factor of machining distortion. Thus, a bulk stress characterization is essential to reduce manufacturing costs linked to machining distortion. This paper proposes a method for bulk stress characterization on aluminium machining blanks, suitable for industrial application given its low requirements on equipment, labour expertise, and computation time. The method couples the effects of bulk residual stresses, machining stresses resulting from cutting loads on the surface and raw geometry of the blanks, and presents no size limitations. Experimental results confirm the capability of the proposed method to measure bulk residual stresses effectively and its practicality for industrial implementation. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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14 pages, 8697 KiB

Open AccessArticle

Pseudo-random Path Generation Algorithms and Strategies for the Surface Quality Improvement of Optical Aspherical Components

by Jun Zha, Hangcheng Zhang, Yipeng Li and Yaolong Chen

Materials 2020, 13(5), 1216; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13051216 - 08 Mar 2020

Cited by 6 | Viewed by 2322

Abstract

This study proposes two path generation algorithms to diminish the superposition of the convolution effect on the polishing path in computer-controlled optical surfacing. According to the polishing of aluminum-alloy based hyperboloid optical components, different proportions of polishing agents were blended. Then, the surface roughness of the optical components were determined through a validation experiment of the algorithms. Furthermore, the relationship between surface roughness and the polishing agent concentration, and the compensation strategies for surface roughness were analyzed. The results show that the two algorithms effectively compensated for surface waviness. The findings support the strategies for improving the surface quality of optical components with aspherical surfaces. Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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13 pages, 9779 KiB

Open AccessArticle

Surface Analysis of Wire-Electrical-Discharge-Machining-Processed Shape-Memory Alloys

by Rakesh Chaudhari, Jay J. Vora, Vivek Patel, L. N. López de Lacalle and D. M. Parikh

Materials 2020, 13(3), 530; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13030530 - 22 Jan 2020

Cited by 68 | Viewed by 4137

Abstract

Shape-memory alloys such as nitinol are gaining popularity as advanced materials in the aerospace, medical, and automobile sectors. However, nitinol is a difficult-to-cut material because of its versatile specific properties such as the shape-memory effect, superelasticity, high specific strength, high wear and corrosion resistance, and severe strain hardening. Anunconventional machining process like wire-electrical-discharge-machining (WEDM) can be effectively and efficiently used for the machining of such alloys, although the WEDM-induced surface integrity of nitinol hassignificant impact on material performance. Therefore, this work investigated the surface integrity of WEDM-processed nitinol samples using digital microscopy imaging, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis. Three-dimensional analysis of the surfaces was carried out in two different patterns (along the periphery and the vertical plane of the machined surface) andrevealed that surface roughness was maximalat the point where the surface was largely exposed to the WEDM dielectric fluid. To attain the desired surface roughness, appropriate discharge energy is required that, in turn, requires the appropriate parameter settings of the WEDM process. Different SEM image analyses showed a reduction in microcracks and pores, and in globule-density size at optimized parameters. EDX analysis revealed the absence of wire material on the machined surface Full article

(This article belongs to the Special Issue Composites, Alloys and Advanced Processes for Manufacturing in Aeronautics and Aerospace)

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