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Advances in the Experimentation and Numerical Modeling of Material Joining Processes

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Materials Simulation and Design".

Deadline for manuscript submissions: closed (20 September 2023) | Viewed by 35459

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Special Issue Editor

Special Issue Information

Dear Colleagues,

Nowadays, structural design is facing major challenges in the associated joining processes, such as material selection, different thermal coefficients and melting points, multi-material joining, the joining of thin-walled structures, traditional process effectiveness for new materials, cost efficiency and ecological issues. To provide a strong, reliable and lightweight solution for a given application, the designer should either consider hybrid joining or choose from a large variety of available processes, such as welding, brazing, riveting, mechanical fastening, adhesive bonding, clinching, friction stir welding, laser welding, diffusion welding, amongst others. These joining processes have evolved towards optimization and cost reduction in the early design stages in terms of their implementation and industrialization, destructive and non-destructive testing, and either analytical or numerical modeling. Numerical modeling is particularly effective for simulating complex geometries, different load scenarios and materials with plasticity or anisotropy. The finite element method, together with fracture mechanics techniques, is a powerful and common approach employed in the scientific community, but less applied for the study of complex loads, such as high strain rates, fatigue or impact, and it is seldom used in the industry. To develop state-of-the-art techniques and disseminate the recent advances in all types of joining, either experimental or numerical, this Special Issue intends to bring together a significant number of high-quality contributions to this field of research through innovative and original works, subsequently promoting their dissemination via open access publishing.

Dr. Raul D.S.G. Campilho
Guest Editor

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Keywords

  • joining process
  • welding
  • brazing
  • riveting
  • mechanical fastening
  • adhesive bonding
  • clinching
  • friction stir welding
  • laser welding
  • diffusion welding
  • hybrid joining
  • experimental testing
  • numerical modeling
  • strength prediction
  • failure path prediction
  • finite element method
  • fracture mechanics
  • static load
  • dynamic load
  • impact load
  • fatigue load
  • residual stress
  • mechanical properties
  • thin-walled structures

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Published Papers (22 papers)

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Editorial

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6 pages, 217 KiB  
Editorial
Advances in the Experimentation and Numerical Modeling of Material Joining Processes
by Raul D. S. G. Campilho
Materials 2024, 17(1), 130; https://doi.org/10.3390/ma17010130 - 27 Dec 2023
Viewed by 692
Abstract
Material joining processes are a critical factor in engineering structures since they influence such structures’ structural integrity, performance, and longevity [...] Full article

Research

Jump to: Editorial, Review

21 pages, 14245 KiB  
Article
Simulation and Experimental of Infiltration and Solidification Process for Al2O3(3D)/5083Al Interpenetrating Phase Composite for High Speed Train Prepared by Low-Pressure Infiltration
by Yanli Jiang, Pianpian Xu, Chen Zhang, Fengjun Jin, Yichao Li, Xiuling Cao and Liang Yu
Materials 2023, 16(20), 6634; https://doi.org/10.3390/ma16206634 - 11 Oct 2023
Viewed by 614
Abstract
Understanding the infiltration and solidification processes of liquid 5083Al alloy into Al2O3 three-dimensional reticulated porous ceramic (Al2O3(3D) RPC) is essential for optimizing the microstructure and properties of Al2O3(3D)/5083Al interpenetrating phase composites (IPCs) prepared [...] Read more.
Understanding the infiltration and solidification processes of liquid 5083Al alloy into Al2O3 three-dimensional reticulated porous ceramic (Al2O3(3D) RPC) is essential for optimizing the microstructure and properties of Al2O3(3D)/5083Al interpenetrating phase composites (IPCs) prepared by low-pressure infiltration process (LPIP). This study employs ProCAST software to simulate the infiltration and solidification processes of liquid 5083Al with pouring velocities (PV) of 0.4 m/s infiltrating into Al2O3(3D) RPC preforms with varying porosities at different pouring temperatures (PT) to prepare Al2O3(3D)/5083Al IPCs using LPIP. The results demonstrate that pore diameter of Al2O3(3D) RPC preforms and PT of liquid 5083Al significantly influence the of the infiltration. Solidification process analysis reveals that the Al2O3(3D) RPC preform with smaller pore diameters allows the lower pouring velocity of 5083Al to solidify faster compared to the preform with larger pore diameters. Al2O3(3D)/5083Al IPCs were prepared successfully from Al2O3(3D) RPC porosity of 15 PPI with liquid 5083Al at PV 0.4 m/s and PT 800 °C using LPIP, resulting in nearly fully dense composites, where both Al2O3(3D) RPCs and 5083Al interpenetrate throughout the microstructure. The infiltration and solidification defects were reduced under air pressure of 0.3 MPa (corresponding to PV of 0.4 m/s) during LPIP. Finite volume method simulations are in good agreement with experimental data, validating the suitability of the simplified model for Al2O3(3D) RPCs in the infiltration simulation. Full article
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31 pages, 17584 KiB  
Article
FEM Numerical and Experimental Work on Extrusion Welding of 7021 Aluminum Alloy
by Dariusz Leśniak, Wojciech Libura, Beata Leszczyńska-Madej, Marek Bogusz, Jacek Madura, Bartłomiej Płonka, Sonia Boczkal and Henryk Jurczak
Materials 2023, 16(17), 5817; https://doi.org/10.3390/ma16175817 - 24 Aug 2023
Cited by 2 | Viewed by 903
Abstract
Extrusion welding of AlZnMg alloys encounters great technological difficulties in practice associated with high shaping forces and the low quality of longitudinal welds. Three different chemical compositions of 7021 aluminum alloy, differing in terms of Zn and Mg contents, were used in the [...] Read more.
Extrusion welding of AlZnMg alloys encounters great technological difficulties in practice associated with high shaping forces and the low quality of longitudinal welds. Three different chemical compositions of 7021 aluminum alloy, differing in terms of Zn and Mg contents, were used in the first stage of the research. The laboratory device modelling the behavior of metal in welding chambers of the porthole die was applied to examine the ability of 7021 alloys to produce high-quality joints. The weldability tests were carried out for different welding temperatures—400, 450 and 500 °C—and for a fixed welding pressure of 300 MPa. The microstructural effects in pressure-welds were evaluated with the use of OM and SEM/EDS. The temperature–pressure parameters in the welding chambers were analyzed by using the FEM method for original porthole dies while extruding tubes with dimensions of Ø50 × 2 mm. Finally, the industrial extrusion trials were performed with examination of the structure and strength of the seam welds. It was found that it is possible to produce high-quality high-strength welds in tubes extruded from AlZnMg alloys in industrial conditions (the strength of welds in the range of 96–101% of the strength of the basic non-welded material) through properly matched alloy chemical composition of the alloy, construction of the porthole dies and temperature–speed conditions of deformation. Full article
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17 pages, 13473 KiB  
Article
Effects of Partial-Contact Tool Tilt Angle on Friction Stir Welded AA1050 Aluminum Joint Properties
by Mahmoud E. Abdullah, M. Nafea M. Rohim, M. M. Mohammed and Hamed Aghajani Derazkola
Materials 2023, 16(11), 4091; https://doi.org/10.3390/ma16114091 - 31 May 2023
Cited by 5 | Viewed by 956
Abstract
This study aims to investigate the impact of partial-contact tool tilt angle (TTA) on the mechanical and microstructure properties of the AA1050 alloy friction stir weld (FSW). Three levels of partial-contact TTA were tested, 0°, 1.5°, and 3°, compared to previous studies on [...] Read more.
This study aims to investigate the impact of partial-contact tool tilt angle (TTA) on the mechanical and microstructure properties of the AA1050 alloy friction stir weld (FSW). Three levels of partial-contact TTA were tested, 0°, 1.5°, and 3°, compared to previous studies on total-contact TTA. The weldments were evaluated using surface roughness, tensile tests, microhardness, microstructure, and fracture analysis. The results show that in partial-contact conditions, increasing TTA decreases the generated heat in the joint line and increases the possibility of FSW tool wear. This trend was the opposite of joints that were friction stir welded via total-contact TTA. The microstructure of the FSW sample was finer at higher partial-contact TTA, while the possibility of defect formation at the root of the stir zone in higher TTA was more than in lower TTA. The robust sample prepared at 0° TTA had 45% of AA1050 alloy strength. The maximum recorded heat in 0° TTA was 336 °C and the ultimate tensile strength of this sample was 33 MPa. The elongation of the 0° TTA welded sample was 75% base metal, and the average hardness of the stir zone was 25 Hv. The fracture surface analysis of the 0° TTA welded sample consisted of a small dimple, indicating the brittle fracture mode. Full article
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17 pages, 6724 KiB  
Article
Mechanical Performance and Microstructural Evolution of Rotary Friction Welding of Acrylonitrile Butadiene Styrene and Polycarbonate Rods
by Chil-Chyuan Kuo, Naruboyana Gurumurthy, Hong-Wei Chen and Song-Hua Hunag
Materials 2023, 16(9), 3295; https://doi.org/10.3390/ma16093295 - 22 Apr 2023
Cited by 6 | Viewed by 1243
Abstract
Rotary friction welding (RFW) is a green manufacturing technology with environmental pollution in the field of joining methods. In practice, the welding quality of the friction-welded parts was affected by the peak temperature in the weld joint during the RFW of dissimilar plastic [...] Read more.
Rotary friction welding (RFW) is a green manufacturing technology with environmental pollution in the field of joining methods. In practice, the welding quality of the friction-welded parts was affected by the peak temperature in the weld joint during the RFW of dissimilar plastic rods. In industry, polycarbonate (PC) and acrylonitrile butadiene styrene (ABS) are two commonly used plastics in consumer products. In this study, the COMSOL multiphysics software was employed to estimate the peak temperature in the weld joint during the RFW of PC and ABS rods. After RFW, the mechanical performance and microstructural evolution of friction-welded parts were investigated experimentally. The average Shore A surface hardness, flexural strength, and impact energy are directly proportional to the rotation speed of the RFW. The quality of RFW is excellent, since the welding strength in the weld joint is better than that of the ABS base materials. The fracture occurs in the ABS rods since their brittleness is higher than that of the PC rods. The average percentage error of predicting the peak temperature using COMSOL software using a mesh element count of 875,688 for five different rotation speeds is about 16.6%. The differential scanning calorimetry curve for the friction-welded parts welded at a rotation speed of 1350 rpm shows an endothermic peak between 400 to 440 °C and an exothermic peak between 600 to 700 °C, showing that the friction-welded parts have better mechanical properties. Full article
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16 pages, 3785 KiB  
Article
A Numerical Study on the Effect of Tool Speeds on Temperatures and Material Flow Behaviour in Refill Friction Stir Spot Welding of Thin AA7075-T6 Sheets
by Venkata Somi Reddy Janga, Mokhtar Awang and Srinivasa Rao Pedapati
Materials 2023, 16(8), 3108; https://doi.org/10.3390/ma16083108 - 14 Apr 2023
Cited by 2 | Viewed by 1102
Abstract
A three-dimensional (3D) numerical model was created to simulate and analyze the effect of tool rotational speeds (RS) and plunge rate (PR) on refill friction stir spot welding (refill FSSW) of AA7075-T6 sheets. The numerical model was validated by comparing the temperatures recorded [...] Read more.
A three-dimensional (3D) numerical model was created to simulate and analyze the effect of tool rotational speeds (RS) and plunge rate (PR) on refill friction stir spot welding (refill FSSW) of AA7075-T6 sheets. The numerical model was validated by comparing the temperatures recorded at a subset of locations with those recorded at the exact locations in prior experimental studies from the literature. The peak temperature at the weld center obtained from the numerical model differed by an error of 2.2%. The results showed that with the rise in RS, there was an increase in weld temperatures, effective strains, and time-averaged material flow velocities. With the rise in PR, the temperatures and effective strains were reduced. Material movement in the stir zone (SZ) was improved with the increment of RS. With the rise in PR, the top sheet’s material flow was improved, and the bottom sheet’s material flow was reduced. A deep understanding of the effect of tool RS and PR on refill FSSW joint strength were achieved by correlating the thermal cycles and material flow velocity results obtained from the numerical models to the lap shear strength (LSS) from the literature. Full article
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16 pages, 30003 KiB  
Article
Individual Effects of Alkali Element and Wire Structure on Metal Transfer Process in Argon Metal-Cored Arc Welding
by Hanh Van Bui, Ngoc Quang Trinh, Shinichi Tashiro, Tetsuo Suga, Tomonori Kakizaki, Kei Yamazaki, Ackadech Lersvanichkool, Anthony B. Murphy and Manabu Tanaka
Materials 2023, 16(8), 3053; https://doi.org/10.3390/ma16083053 - 12 Apr 2023
Cited by 2 | Viewed by 1026
Abstract
This study aimed to clarify the effect of wire structure and alkaline elements in wire composition on metal transfer behavior in metal-cored arc welding (MCAW). A comparison of metal transfer in pure argon gas was carried out using a solid wire (wire 1), [...] Read more.
This study aimed to clarify the effect of wire structure and alkaline elements in wire composition on metal transfer behavior in metal-cored arc welding (MCAW). A comparison of metal transfer in pure argon gas was carried out using a solid wire (wire 1), a metal-cored wire without an alkaline element (wire 2), and another metal-cored wire with 0.084 mass% of sodium (wire 3). The experiments were conducted under 280 and 320 A welding currents, observed by high-speed imaging techniques equipped with laser assistance and bandpass filters. At 280 A, wire 1 showed a streaming transfer mode, while the others showed a projected one. When the current was 320 A, the metal transfer of wire 2 changed to streaming, while wire 3 remained projected. As sodium has a lower ionization energy than iron, the mixing of sodium vapor into the iron plasma increases its electrical conductivity, raising the proportion of current flowing through metal vapor plasma. As a result, the current flows to the upper region of the molten metal on the wire tip, with the resulting electromagnetic force causing droplet detachment. Consequently, the metal transfer mode in wire 3 remained projected. Furthermore, weld bead formation is the best for wire 3. Full article
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10 pages, 3294 KiB  
Article
Mechanical Properties and Microstructure of Austenite—Ferrite Duplex Stainless Steel Hybrid (Laser + GMAW) and SAW Welded Joint
by Ryszard Krawczyk, Jacek Słania, Grzegorz Golański and Tomasz Pfeifer
Materials 2023, 16(7), 2909; https://doi.org/10.3390/ma16072909 - 06 Apr 2023
Cited by 1 | Viewed by 1314
Abstract
The purpose of the research was to develop a technology for producing thick-walled duplex steel welded joints. The material used in the research was X2CrNiMoN22 duplex steel in the form of a 15 mm thick plate. The welded joint was produced by the [...] Read more.
The purpose of the research was to develop a technology for producing thick-walled duplex steel welded joints. The material used in the research was X2CrNiMoN22 duplex steel in the form of a 15 mm thick plate. The welded joint was produced by the modern, high-performance Hybrid Laser Arc Welding (HLAW) method. The HLAW method involves welding a joint using a laser, the Gas Metal Arc Welding (GMAW) method and the Submerged Arc Welding (SAW) method. The HLAW method was used to make the root pass of the double butt welded joint, while the filler passes were made by the SAW method. The obtained welded joint was subjected to non-destructive and destructive testing. The non-destructive and macroscopic tests allowed the joint to be classified to the quality level B. Microscopic examinations revealed the presence of ferritic–austenitic microstructure in the base material and the weld, with different ferrite content in specific joint areas. The analysed joint had high strength properties (tensile strength (TS) ~ 790 ± 7 MPa) and high ductility of weld metal (~160 ± 4 J) heat-affected zone (~216 ± 26 J), and plasticity (bending angle of 180° with no macrocracks). At the same time, hardness on the cross-section of the welded joint did not exceed 280 HV10. Full article
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24 pages, 10553 KiB  
Article
Ultrasonic Welding of PEEK Plates with CF Fabric Reinforcement—The Optimization of the Process by Neural Network Simulation
by Vladislav O. Alexenko, Sergey V. Panin, Dmitry Yu. Stepanov, Anton V. Byakov, Alexey A. Bogdanov, Dmitry G. Buslovich, Konstantin S. Panin and Defang Tian
Materials 2023, 16(5), 2115; https://doi.org/10.3390/ma16052115 - 06 Mar 2023
Cited by 4 | Viewed by 1612
Abstract
The optimal mode for ultrasonic welding (USW) of the “PEEK–ED (PEEK)–prepreg (PEI impregnated CF fabric)–ED (PEEK)–PEEK” lap joint was determined by artificial neural network (ANN) simulation, based on the sample of the experimental data expanded with the expert data set. The experimental verification [...] Read more.
The optimal mode for ultrasonic welding (USW) of the “PEEK–ED (PEEK)–prepreg (PEI impregnated CF fabric)–ED (PEEK)–PEEK” lap joint was determined by artificial neural network (ANN) simulation, based on the sample of the experimental data expanded with the expert data set. The experimental verification of the simulation results showed that mode 10 (t = 900 ms, P = 1.7 atm, τ = 2000 ms) ensured the high strength properties and preservation of the structural integrity of the carbon fiber fabric (CFF). Additionally, it showed that the “PEEK–CFF prepreg–PEEK” USW lap joint could be fabricated by the “multi-spot” USW method with the optimal mode 10, which can resist the load per cycle of 50 MPa (the bottom HCF level). The USW mode, determined by ANN simulation for the neat PEEK adherends, did not provide joining both particulate and laminated composite adherends with the CFF prepreg reinforcement. The USW lap joints could be formed when the USW durations (t) were significantly increased up to 1200 and 1600 ms, respectively. In this case, the elastic energy is transferred more efficiently to the welding zone through the upper adherend. Full article
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24 pages, 28257 KiB  
Article
Experimental Study of Steel–Aluminum Joints Made by RSW with Insert Element and Adhesive Bonding
by Anna Guzanová, Janette Brezinová, Ján Varga, Miroslav Džupon, Marek Vojtko, Erik Janoško, Ján Viňáš, Dagmar Draganovská and Ján Hašuľ
Materials 2023, 16(2), 864; https://doi.org/10.3390/ma16020864 - 16 Jan 2023
Cited by 4 | Viewed by 1912
Abstract
This work focuses on joining steel to aluminum alloy using a novel method of joining by resistance spot welding with an insert element based on anticorrosive steel in combination with adhesive bonding. The method aims to reduce the formation of brittle intermetallic compounds [...] Read more.
This work focuses on joining steel to aluminum alloy using a novel method of joining by resistance spot welding with an insert element based on anticorrosive steel in combination with adhesive bonding. The method aims to reduce the formation of brittle intermetallic compounds by using short welding times and a different chemical composition of the insert element. In the experiment, deep-drawing low-carbon steel, HSLA zinc-coated steel and precipitation-hardened aluminum alloy 6082 T6 were used. Two types of adhesives—one based on rubber and the other based on epoxy resin—were used for adhesive bonding, while the surfaces of the materials joined were treated with a unique adhesion-improving agent based on organosilanes. The surface treatment improved the chemical bonding between the substrate and adhesive. It was proved, that the use of an insert element in combination with adhesive bonding is only relevant for those adhesives that have a load capacity just below the yield strength of the substrates. For bonded joints with higher load capacities, plastic deformation of the substrates occurs, which is unacceptable, and thus, the overall contribution of the insert element to the load capacity of the joint becomes negligible. The results also show that the combination of the resistance spot welding of the insert element and adhesive bonding facilitates the joining process of galvanized and nongalvanized steels with aluminum alloys and suppresses the effect of brittle intermetallic phases by minimizing the joining area and welding time. It is possible to use the synergistic effect of insert element welding and adhesive bonding to achieve increased energy absorption of the joint under stress. Full article
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14 pages, 10571 KiB  
Article
Retaining Mechanical Properties of GMA-Welded Joints of 9%Ni Steel Using Experimentally Produced Matching Ferritic Filler Metal
by Abdel-Monem El-Batahgy, Mohamed Raafat Elkousy, Ahmed Abd Al-Rahman, Andrey Gumenyuk, Michael Rethmeier and Sergej Gook
Materials 2022, 15(23), 8538; https://doi.org/10.3390/ma15238538 - 30 Nov 2022
Viewed by 1141
Abstract
Motivated by the loss of tensile strength in 9%Ni steel arc-welded joints performed using commercially available Ni-based austenitic filler metals, the viability of retaining tensile strength using an experimentally produced matching ferritic filler metal was confirmed. Compared to the austenitic Ni-based filler metal [...] Read more.
Motivated by the loss of tensile strength in 9%Ni steel arc-welded joints performed using commercially available Ni-based austenitic filler metals, the viability of retaining tensile strength using an experimentally produced matching ferritic filler metal was confirmed. Compared to the austenitic Ni-based filler metal (685 MPa), higher tensile strength in gas metal arc (GMA) welded joints was achieved using a ferritic filler metal (749 MPa) due to its microstructure being similar to the base metal (645 MPa). The microstructure of hard martensite resulted in an impact energy of 71 J (−196 °C), which was two times higher than the specified minimum value of ≥34 J. The tensile and impact strength of the welded joint is affected not only by its microstructure, but also by the degree of its mechanical mismatch depending on the type of filler metal. Welds with a harder microstructure and less mechanical mismatch are important for achieving an adequate combination of tensile strength and notched impact strength. This is achievable with the cost-effective ferritic filler metal. A more desirable combination of mechanical properties is guaranteed by applying low preheating temperature (200 °C), which is a more practicable and economical solution compared to the high post-weld heat treatment (PWHT) temperature (580 °C) suggested by other research. Full article
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12 pages, 13358 KiB  
Article
Modeling of Probeless Friction Stir Spot Welding of AA2024/AISI304 Steel Lap Joint
by Mariia Rashkovets, Nicola Contuzzi and Giuseppe Casalino
Materials 2022, 15(22), 8205; https://doi.org/10.3390/ma15228205 - 18 Nov 2022
Cited by 4 | Viewed by 1260
Abstract
In the present study, AA2024 aluminum alloy and AISI304 stainless steel were welded in a lap joint configuration by Probeless Friction Stir Spot Welding (P-FSSW) with a flat surface tool. A full factorial DOE plan was performed. The effect of the tool force [...] Read more.
In the present study, AA2024 aluminum alloy and AISI304 stainless steel were welded in a lap joint configuration by Probeless Friction Stir Spot Welding (P-FSSW) with a flat surface tool. A full factorial DOE plan was performed. The effect of the tool force (4900, 7350 N) and rotational speed (500, 1000, 1500, 2000 RPM) was analyzed regarding the microstructure and microhardness study. A two-dimensional arbitrary Eulerian–Lagrangian FEM model was used to clarify the temperature distribution and material flow within the welds. The experimental results for the weld microstructures were used to validate the temperature field of the numerical model. The results showed that the tool rotation speed had an extensive influence on the heat generation, whereas the load force mainly acted on the material flow. Full article
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18 pages, 9126 KiB  
Article
Tensile Behaviour of Double- and Triple-Adhesive Single Lap Joints Made with Spot Epoxy and Double-Sided Adhesive Tape
by Przemysław Golewski
Materials 2022, 15(21), 7855; https://doi.org/10.3390/ma15217855 - 07 Nov 2022
Cited by 3 | Viewed by 1586
Abstract
Dual adhesives are mainly used to increase the strength of single lap joints (SLJs) by reducing the stress concentration at its ends. However, they can also be used to design the characteristics of the joint so that its operation and failure occur in [...] Read more.
Dual adhesives are mainly used to increase the strength of single lap joints (SLJs) by reducing the stress concentration at its ends. However, they can also be used to design the characteristics of the joint so that its operation and failure occur in several stages. This paper presents the results of uniaxial tensile tests for dual-adhesive and triple-adhesive SLJs. The adherends were made of aluminum and glass fiber-reinforced polymer (GFRP) composite. For dual-adhesive SLJs, 10 epoxies and 1.6 mm thick double-sided adhesive tape were used. The stiffest (Epidian 53 (100 g) + “PAC” hardener (80 g)) and most elastic (Scotch-Weld 2216 B/A Translucent) joints were determined, which were then used in a triple-adhesive joint with the same double-sided adhesive tape. Circular holes of different diameters from 8 mm to 20 mm were made in the double-sided adhesive tape, which were filled with liquid epoxy adhesive by injection after the adherends were joined. By using the double-sided adhesive tape, the geometry of the epoxy joints was perfect, free of spews, and had a constant thickness. The effect of the spot epoxy joint diameters and the arrangement of stiff and elastic joints in the SLJs were analyzed using digital image correlation (DIC). Full article
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13 pages, 3398 KiB  
Article
Sustainability Study of Concrete Blocks with Wood Chips Used in Structural Walls in Seismic Areas
by Simon Pescari, Laurentiu Budau, Razvan Ciubotaru and Valeriu Stoian
Materials 2022, 15(19), 6659; https://doi.org/10.3390/ma15196659 - 26 Sep 2022
Viewed by 2791
Abstract
The concept of sustainability has become a priority in the construction field, in a context where there is an increasing discussion about reducing carbon dioxide emissions, as the construction industry is one of the most polluting industries with a focus on the production [...] Read more.
The concept of sustainability has become a priority in the construction field, in a context where there is an increasing discussion about reducing carbon dioxide emissions, as the construction industry is one of the most polluting industries with a focus on the production of building materials. At present, the classic solution used for structural masonry walls worldwide is the ceramic block. Given that the production of ceramic blocks represents an environmentally polluting process, the alternative solution of using concrete blocks with wood chips is proposed. The proposed solution is more environmentally friendly, both in terms of production technology and materials used, as it is made of wood chips, wood being a sustainable material. These types of blocks are currently used in non-seismic areas due to their poor structural performance. This paper deals with a study on the use of recyclable materials, such as wood chips, from waste materials and aims to propose viable solutions for the use of this type of blocks for structural walls in seismic areas. Two solutions, including concrete blocks with wood chips, have been proposed and numerical analyses have been carried out. Numerical analyses were also carried out for the classical solutions, so that, finally, a comparison could be made between them from a structural point of view. Following the numerical analysis of four types of walls, the two proposed solutions of concrete blocks with wood chips had the best results in terms of force–displacement relationship. Moreover, the quantitative results are presented in a force–displacement graph for the four wall types. This stage represents the first phase of the research, while phase II will continue with experimental tests of the proposed solutions. Full article
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16 pages, 868 KiB  
Article
A Finite-Difference Based Parallel Solver Algorithm for Online-Monitoring of Resistance Spot Welding
by Tomas Teren, Lars Penter, Christoph Peukert and Steffen Ihlenfeldt
Materials 2022, 15(18), 6348; https://doi.org/10.3390/ma15186348 - 13 Sep 2022
Cited by 1 | Viewed by 1232
Abstract
Although resistance spot welding (RSW) was invented at the beginning of the last century, the online-monitoring and control of RSW is still a technological challenge and of economic and ecological importance. Process, material and geometry parameters of RSW are stored in the database [...] Read more.
Although resistance spot welding (RSW) was invented at the beginning of the last century, the online-monitoring and control of RSW is still a technological challenge and of economic and ecological importance. Process, material and geometry parameters of RSW are stored in the database of the process control system. Prospectively, these accumulated data could serve as the base for data-driven and physics-based models to monitor the spot weld process in real-time. The objective of this paper is to present a finite-difference based parallel solver algorithm to simulate RSW time-efficiently. The Peaceman–Rachford scheme was combined with the Thomas algorithm to compute the electrical–thermal interdependencies of the resistance spot welding process within seconds. Finally, the electric–thermal model is verified by a convergence analysis and parameter study. Full article
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12 pages, 4746 KiB  
Article
Molecular Dynamics Study on the Welding Behavior in Dissimilar TC4-TA17 Titanium Alloys
by Peng Ou, Zengqiang Cao, Ju Rong and Xiaohua Yu
Materials 2022, 15(16), 5606; https://doi.org/10.3390/ma15165606 - 16 Aug 2022
Cited by 5 | Viewed by 1983
Abstract
Titanium alloys have become the material of choice for marine parts manufacturing due to their high specific strength and excellent resistance to seawater corrosion. However, it is still challenging for a single titanium alloy to meet the comprehensive specifications of a structural component. [...] Read more.
Titanium alloys have become the material of choice for marine parts manufacturing due to their high specific strength and excellent resistance to seawater corrosion. However, it is still challenging for a single titanium alloy to meet the comprehensive specifications of a structural component. In this study, we have applied a molecular dynamics approach to simulate the aging phase transformation, K-TIG welding process, and mechanical properties of the TC4-TA17 (Ti6Al4V-Ti4Al2V) alloy. The results show that during the aging phase transformation process, changes in the structure of the titanium alloys are mainly manifested in the precipitation of a new phase from the sub-stable β-phase, and after the state stabilization, the α-phase content reaches 45%. Moreover, during the melting and diffusion process of TC4-TA17, aluminum atoms near the interface diffuse, followed by titanium atoms, while relatively few vanadium atoms are involved in the diffusion. Finally, the results of tensile simulations of the TC4-TA17 alloy after welding showed that stress values can reach up to 9.07 GPa and that the mechanical properties of the alloy in the weld zone are better than those of the single alloys under the same conditions. This study will provide theoretical support for the optimization of process parameters for TC4-TA17 alloy welding. Full article
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13 pages, 6645 KiB  
Article
Corrosion Behavior of Friction Stir Welded AA8090-T87 Aluminum Alloy
by Chandrasekaran Shyamlal, Rajesh Shanmugavel, J. T. Winowlin Jappes, Anish Nair, M. Ravichandran, S. Syath Abuthakeer, Chander Prakash, Saurav Dixit and N. I. Vatin
Materials 2022, 15(15), 5165; https://doi.org/10.3390/ma15155165 - 26 Jul 2022
Cited by 16 | Viewed by 1417
Abstract
Aerospace alloys with reduced wall thickness but possessing higher hardness, good tensile strength and reasonable corrosion resistance are essential in manufacturing of structures such as fuselage. In this work, friction stir welding has been carried out on such an aerospace aluminum alloy AA8090 [...] Read more.
Aerospace alloys with reduced wall thickness but possessing higher hardness, good tensile strength and reasonable corrosion resistance are essential in manufacturing of structures such as fuselage. In this work, friction stir welding has been carried out on such an aerospace aluminum alloy AA8090 T87 which contains 2.3% lithium. Tool rotational speed of 900 rpm and traverse speeds of 90 mm/min., 110 mm/min. are the welding parameters. Hardness analysis, surface roughness analysis and corrosion analysis are conducted to analyze the suitability of the joint for the intended application. The samples were corrosion tested in acid alkali solution and they resulted in the formation of pits of varying levels which indicate the extent of surface degradation. Hardness of the samples was measured after corrosion analysis to observe the changes. The analysis suggests that the change in tool traverse speed transformed the corrosion behavior of the joint and affected both the hardness and surface roughness which mitigated the quality of the joint. Full article
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12 pages, 6838 KiB  
Article
Microstructure and Mechanical Properties Analysis of Al/Cu Dissimilar Alloys Joining by Using Conventional and Bobbin Tool Friction Stir Welding
by Kishan Fuse, Vishvesh Badheka, Ankit D. Oza, Chander Prakash, Dharam Buddhi, Saurav Dixit and N. I. Vatin
Materials 2022, 15(15), 5159; https://doi.org/10.3390/ma15155159 - 25 Jul 2022
Cited by 7 | Viewed by 1595
Abstract
The feasibility of producing welding joints between 6061-T6 aluminum and pure copper sheets of 6 mm thickness by conventional friction stir welding (CFSW) and bobbin tool friction stir welding (BTFSW) by using a slot-groove configuration at the joining surface was investigated. The microstructure [...] Read more.
The feasibility of producing welding joints between 6061-T6 aluminum and pure copper sheets of 6 mm thickness by conventional friction stir welding (CFSW) and bobbin tool friction stir welding (BTFSW) by using a slot-groove configuration at the joining surface was investigated. The microstructure of the welded samples was examined by using an optical microscope and X-ray diffraction. Furthermore, the mechanical properties of the weld samples are compared based on the results of the tensile test, hardness measurement, and fractography test. The slot-groove configuration resulted in the presence of a bulk-sized Al block on the Cu side. The microscopic observations revealed the dispersion of fine Cu particles in the stir zone. The presence of intermetallic compounds (IMCs) CuAl2, which are hard and brittle, lowered the strength of the weld joints. The strength of the weld joints produced with BTFSW was superior to that of the C-FSW. The maximum hardness values of 214 HV and 211 HV are reported at the stir zone for BTFSW and CFSW, respectively. The fracture location of all the joints was at the intersection of the stir zone and the thermomechanically affected zone was on the Cu side. Full article
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15 pages, 6562 KiB  
Article
Multi-Objective Welding-Parameter Optimization Using Overlaid Contour Plots and the Butterfly Optimization Algorithm
by Rehan Waheed, Hasan Aftab Saeed and Bilal Anjum Ahmed
Materials 2022, 15(13), 4507; https://doi.org/10.3390/ma15134507 - 27 Jun 2022
Cited by 4 | Viewed by 1457
Abstract
Distortion and residual stress are two unwelcome byproducts of welding. The former diminishes the dimensional accuracy while the latter unfavorably affects the fatigue resistance of the components being joined. The present study is a multi-objective optimization aimed at minimizing both the welding-induced residual [...] Read more.
Distortion and residual stress are two unwelcome byproducts of welding. The former diminishes the dimensional accuracy while the latter unfavorably affects the fatigue resistance of the components being joined. The present study is a multi-objective optimization aimed at minimizing both the welding-induced residual stress as well as distortion. Current, voltage, and welding speed were the welding parameters selected. It was observed that the parameters that minimize distortion were substantially different from those that minimized the residual stress. That is, enhancing dimensional accuracy by minimizing distortion results in an intensification of residual stresses. A compromise between the two objectives was therefore necessary. The contour plots produced from the response surfaces of the two objectives were overlaid to find a region with feasible parameters for both. This feasible region was used as the domain wherein to apply the novel butterfly optimization algorithm (BOA). This is the first instance of the application of the BOA to a multi-objective welding problem. Weld simulation and a confirmatory experiment based on the optimum weld parameters thus obtained corroborate the efficacy of the framework. Full article
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Review

Jump to: Editorial, Research

18 pages, 5619 KiB  
Review
A Review of Numerical Simulation of Laser–Arc Hybrid Welding
by Zhaoyang Wang, Mengcheng Gong, Longzao Zhou and Ming Gao
Materials 2023, 16(9), 3561; https://doi.org/10.3390/ma16093561 - 06 May 2023
Cited by 2 | Viewed by 1670
Abstract
Laser–arc hybrid welding (LAHW) is known to achieve more stable processes, better mechanical properties, and greater adaptability through the synergy of a laser and an arc. Numerical simulations play a crucial role in deepening our understanding of this interaction mechanism. In this paper, [...] Read more.
Laser–arc hybrid welding (LAHW) is known to achieve more stable processes, better mechanical properties, and greater adaptability through the synergy of a laser and an arc. Numerical simulations play a crucial role in deepening our understanding of this interaction mechanism. In this paper, we review the current work on numerical simulations of LAHW, including heat source selection laws, temperature field, flow field, and stress field results. We also discuss the influence of laser–arc interaction on weld defects and mechanical properties and provide suggestions for the development of numerical simulations of LAHW. Full article
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33 pages, 12930 KiB  
Review
Friction Stir Welding of Aluminum in the Aerospace Industry: The Current Progress and State-of-the-Art Review
by Mohamed M. Z. Ahmed, Mohamed M. El-Sayed Seleman, Dariusz Fydrych and Gürel Çam
Materials 2023, 16(8), 2971; https://doi.org/10.3390/ma16082971 - 08 Apr 2023
Cited by 53 | Viewed by 4719
Abstract
The use of the friction stir welding (FSW) process as a relatively new solid-state welding technology in the aerospace industry has pushed forward several developments in different related aspects of this strategic industry. In terms of the FSW process itself, due to the [...] Read more.
The use of the friction stir welding (FSW) process as a relatively new solid-state welding technology in the aerospace industry has pushed forward several developments in different related aspects of this strategic industry. In terms of the FSW process itself, due to the geometric limitations involved in the conventional FSW process, many variants have been required over time to suit the different types of geometries and structures, which has resulted in the development of numerous variants such as refill friction stir spot welding (RFSSW), stationary shoulder friction stir welding (SSFSW), and bobbin tool friction stir welding (BTFSW). In terms of FSW machines, significant development has occurred in the new design and adaptation of the existing machining equipment through the use of their structures or the new and specially designed FSW heads. In terms of the most used materials in the aerospace industry, there has been development of new high strength-to-weight ratios such as the 3rd generation aluminum–lithium alloys that have become successfully weldable by FSW with fewer welding defects and a significant improvement in the weld quality and geometric accuracy. The purpose of this article is to summarize the state of knowledge regarding the application of the FSW process to join materials used in the aerospace industry and to identify gaps in the state of the art. This work describes the fundamental techniques and tools necessary to make soundly welded joints. Typical applications of FSW processes are surveyed, including friction stir spot welding, RFSSW, SSFSW, BTFSW, and underwater FSW. Conclusions and suggestions for future development are proposed. Full article
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25 pages, 14854 KiB  
Review
The Characteristic Microstructures and Properties of Steel-Based Alloy via Additive Manufacturing
by Chunlei Shang, Honghui Wu, Guangfei Pan, Jiaqi Zhu, Shuize Wang, Guilin Wu, Junheng Gao, Zhiyuan Liu, Ruidi Li and Xinping Mao
Materials 2023, 16(7), 2696; https://doi.org/10.3390/ma16072696 - 28 Mar 2023
Cited by 5 | Viewed by 1702
Abstract
Differing from metal alloys produced by conventional techniques, metallic products prepared by additive manufacturing experience distinct solidification thermal histories and solid−state phase transformation processes, resulting in unique microstructures and superior performance. This review starts with commonly used additive manufacturing techniques in steel−based alloy [...] Read more.
Differing from metal alloys produced by conventional techniques, metallic products prepared by additive manufacturing experience distinct solidification thermal histories and solid−state phase transformation processes, resulting in unique microstructures and superior performance. This review starts with commonly used additive manufacturing techniques in steel−based alloy and then some typical microstructures produced by metal additive manufacturing technologies with different components and processes are summarized, including porosity, dislocation cells, dendrite structures, residual stress, element segregation, etc. The characteristic microstructures may exert a significant influence on the properties of additively manufactured products, and thus it is important to tune the components and additive manufacturing process parameters to achieve the desired microstructures. Finally, the future development and prospects of additive manufacturing technology in steel are discussed. Full article
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