Welding Processes in Advanced Manufacturing

Advanced manufacturing encompasses a range of innovative techniques that optimize production processes for efficiency, quality and sustainability [1]. It integrates cutting-edge technologies like automation, robotics, additive manufacturing and data analytics to enhance traditional manufacturing methods [2]. This approach enables industries to achieve higher precision, reduced waste and increased flexibility in responding to market demands. Key industries such as aerospace, automotive and electronics benefit from its transformative impact. Research and development in advanced manufacturing continue to shape its evolution and expand its applications [3-5]. Advanced manufacturing encompasses a range of cutting-edge technologies that enhance efficiency, precision and sustainability in production processes. In this context, welding processes have undergone remarkable transformations, enabling industries to push the boundaries of innovation. This article delves into the various welding processes that have emerged within the realm of advanced manufacturing, highlighting their benefits, applications and contributions to the modern industrial landscape. Advanced manufacturing has emerged as a driving force in modern industries, revolutionizing production processes, improving product quality and enhancing sustainability [3]. This transformative approach integrates cutting-edge technologies and techniques to optimize manufacturing operations, thereby enabling industries to stay competitive in today’s rapidly evolving market landscape. Welding has been an essential process in manufacturing for centuries, bringing together materials to create structures and products of various scales [6- 9]. However, with the advent of advanced manufacturing techniques, the role of welding has evolved significantly.

Defining advanced manufacturing

Advanced manufacturing encompasses a wide range of innovative techniques and technologies that aim to enhance traditional manufacturing processes [2]. It leverages automation, robotics, additive manufacturing, data analytics and other sophisticated tools to improve efficiency, precision and flexibility. The primary goal of advanced manufacturing is to create higher quality products with reduced lead times and minimal waste, thus meeting the demands of consumers and markets more effectively [3-5].

Technologies driving advanced manufacturing

Additive manufacturing (3D Printing): One of the cornerstones of advanced manufacturing is additive manufacturing, commonly known as 3D printing. This process constructs objects layer by layer using digital designs. It offers unparalleled design freedom, enabling the creation of intricate geometries and lightweight structures that were previously unattainable with traditional methods. The aerospace, healthcare, and automotive industries have particularly benefited from additive manufacturing’s ability to produce complex components with reduced material waste and faster production cycles [10].
Robotics and automation: Automation and robotics have revolutionized manufacturing by introducing efficiency, precision and consistency to production processes. Robots are increasingly used for tasks ranging from assembly and quality control to material handling and packaging. Collaborative robots (COBOTS) work alongside human operators, enhancing productivity and safety in various industries [11].
Data analytics and industrial IoT: Data-driven insights are crucial in optimizing manufacturing processes. The Industrial Internet of Things (IIoT) connects devices and equipment, enabling real-time data collection and analysis. This information helps identify inefficiencies, predict maintenance needs, and make informed decisions that streamline operations and reduce downtime (Figure 1).

Figure 1:Technology roadmap of advanced manufacturing [12].

Benefits and impact

Advanced manufacturing offers several key benefits that impact industries across the board [3]:
A. Improved quality: The integration of advanced technologies minimizes human error and enhances product quality, resulting in more reliable and consistent output.
B. Reduced waste and costs: Techniques like additive manufacturing reduce material waste and automation lowers labor costs by replacing repetitive tasks.
C. Increased customization: Advanced manufacturing enables customization on a scale previously deemed impractical, allowing companies to cater to individual customer preferences.
D. Faster time-to-market: Shorter production cycles and rapid prototyping facilitated by advanced techniques accelerate product development and market entry.

Applications and industries

The influence of advanced manufacturing is felt across a spectrum of industries [7,12]:
a) Aerospace: Advanced manufacturing techniques contribute to the production of lightweight and fuel-efficient components critical for the aerospace industry’s advancements.
b) Automotive: Robotics and automation have revolutionized automotive manufacturing, streamlined production lines and enabled the creation of electric and autonomous vehicles.
c) Healthcare: Additive manufacturing produces customized medical implants and devices, enhancing patient care and surgical procedures.
d) Electronics: Miniaturization and precision are vital in the electronics sector, making advanced manufacturing techniques essential for producing intricate components.

Welding processes Laser welding

Laser welding is a high-precision welding process that utilizes a focused laser beam to create a concentrated heat source. This process is renowned for its ability to produce fine and intricate welds, making it a popular choice in industries where precision is paramount. The focused nature of the laser beam enables welds in narrow spaces and facilitates minimal heat-affected zones. This makes it particularly suitable for applications involving delicate materials, such as medical devices, electronics, and aerospace components. The benefits of laser welding extend beyond precision. Due to the localized heating, distortion is minimized, resulting in less post-welding rework. Moreover, the absence of physical contact between the welding tool and the workpiece reduces wear and tear on equipment. Laser welding also allows for automation, as robots can be programmed to perform highly accurate welds repeatedly. Laser welding has emerged as a cornerstone technology in advanced manufacturing, offering unparalleled precision and efficiency. This process employs a focused laser beam to create localized, high-intensity heat, resulting in rapid fusion between materials. Laser welding’s ability to produce intricate and fine welds makes it a pivotal technique in industries requiring precision, such as aerospace, electronics, and medical device manufacturing [13]. The schematic principle of the laser welding developed at China is depicted in Figure 2.

Figure 2:Schematic showing drainage nozzle with water & gas hybrid drainage method developed by Southeast University in China [17].

One of laser welding’s remarkable advantages is its ability to minimize the heat-affected zone (HAZ), reducing thermal distortion and preserving material properties. This characteristic is particularly crucial when working with delicate or heat-sensitive materials, ensuring the final product’s structural integrity. The focused nature of the laser beam also facilitates welds in tight spaces and enables automation, contributing to efficient production processes. Laser welding finds applications in industries demanding both precision and speed. In the aerospace sector, it is employed to join lightweight components critical for aircraft efficiency. Electronics benefit from the process’s ability to create intricate connections with minimal damage to sensitive components. Medical device manufacturing utilizes laser welding for precise joining of small components, meeting stringent quality and safety standards [14]. However, challenges persist in laser welding, such as its sensitivity to material properties and surface conditions. Variability in material thickness and composition can influence the welding process and result in inconsistent weld quality. Ongoing research focuses on enhancing process reliability through better understanding and control of these factors. In conclusion, laser welding stands as a transformative technology in advanced manufacturing, providing the precision and efficiency required by modern industries. Its capacity to create fine welds, minimize thermal distortion, and enable automation contributes to its growing significance in sectors prioritizing accuracy and innovation [15,16].

Electron beam welding

Electron beam welding is another advanced welding technique that employs a focused energy beam, in this case, a stream of highspeed electrons. This process creates a deep, narrow weld with minimal heat dispersion, ensuring that the surrounding material remains relatively unaffected. Electron beam welding is particularly valuable in industries where joining high-strength materials is crucial, such as aerospace and automotive manufacturing. The lack of atmospheric interaction during welding prevents the introduction of impurities, leading to strong and reliable welds. However, electron beam welding requires a vacuum environment to prevent scattering of electrons by air molecules. This constraint can limit its applicability in some scenarios. Nevertheless, the process’s ability to join dissimilar materials and its capability to produce deep welds with minimal distortion make it a valuable tool in advanced manufacturing. Electron beam welding (EBW) has emerged as a versatile and precise technique within advanced manufacturing, offering exceptional capabilities for joining high-strength materials. This process employs a high-velocity stream of electrons to generate concentrated heat, enabling deep and narrow welds with minimal heat dispersion. EBW’s unique characteristics make it an invaluable tool in industries such as aerospace, automotive, and nuclear power generation, where high-strength and reliable welds are paramount [17-21]. Figure 3 explains the electron beam process.

Figure 3:Electron Beam Welding Process [24].

One of the primary advantages of EBW is its ability to create welds without the need for a filler material, resulting in joints with minimal impurities and reduced risk of corrosion. Moreover, the process takes place in a vacuum or low-pressure environment, preventing atmospheric contamination that could weaken the weld. This makes EBW particularly suitable for applications involving materials that are challenging to weld using conventional methods, such as titanium alloys and refractory metals. EBW’s deep penetration capabilities are advantageous for industries requiring strong and consistent joints. In aerospace, EBW is used for components like aircraft engine turbine blades, ensuring structural integrity and high-temperature performance. The automotive sector benefits from EBW’s ability to join dissimilar materials with minimal distortion, enabling the production of lightweight and fuelefficient vehicles [19]. However, EBW is not without challenges. The vacuum requirement adds complexity and cost to the process, limiting its applicability in certain settings. Additionally, the precise control of electron beams demands skilled operators and sophisticated equipment. Research continues to address these challenges and enhance EBW’s efficiency and accessibility within advanced manufacturing. In conclusion, electron beam welding serves as a crucial technique in advanced manufacturing, enabling precision joining of high-strength materials for industries requiring robust and reliable components. Its deep penetration capabilities and minimal heat-affected zone contribute to its significance in sectors where quality and strength are of utmost importance [22,23].

Friction stir welding

Friction stir welding (FSW) is a solid-state welding process that involves joining materials without reaching their melting points. Instead, a rotating tool generates heat through friction as it moves along the joint between the materials. The softened material is then mechanically mixed together to form a solid weld. FSW is particularly useful for materials that are challenging to weld using traditional fusion techniques, such as aluminum alloys. One of the primary advantages of FSW is the elimination of solidificationrelated defects and the reduction of thermal distortion. This makes it suitable for applications in the shipbuilding, aerospace, and automotive industries. FSW is also eco-friendly, as it generates minimal fumes and reduces energy consumption compared to conventional welding methods. Friction stir welding (FSW) has emerged as a pioneering technique in advanced manufacturing, revolutionizing the joining of materials through a solid-state process. FSW involves a non-consumable rotating tool that generates frictional heat as it moves along the joint, leading to plasticized material that is mechanically mixed to create a solid weld. This innovative approach offers numerous advantages, making it a valuable tool in industries ranging from aerospace to shipbuilding [24,25].

One of FSW’s primary benefits is its ability to join materials that are traditionally challenging to weld using fusion methods, such as aluminum alloys and other high-strength materials. The process eliminates issues associated with solidification and prevents the formation of porosity and other defects commonly found in traditional fusion welding. Moreover, the absence of a melting phase reduces thermal distortion, allowing for intricate components to be manufactured with higher precision. FSW’s applications span various industries. In aerospace, it is used to produce lightweight and high-strength components critical for fuel efficiency. Shipbuilding benefits from FSW’s ability to join thick plates without the need for additional materials or post-welding treatments. The automotive sector leverages FSW for structural components, enhancing vehicle safety and performance [26- 30]. Despite its advantages, FSW is not without challenges. The process demands precise control of parameters such as rotational speed, traverse speed, and tool design. These factors influence the quality of the weld and require skilled operators. Ongoing research focuses on optimizing FSW parameters for different materials and applications to further enhance its efficiency and effectiveness. In conclusion, friction stir welding stands as a cornerstone of advanced manufacturing, enabling solid-state joining with superior properties compared to conventional fusion welding. Its ability to overcome challenges posed by difficult-to-weld materials and its minimal distortion characteristics make it an indispensable tool in modern industries. The role of FSW in the aircraft industry is huge and is depicted in Figure 4.

Figure 4:Current status of FSW and schematic principle [30].

Ultrasonic welding

Ultrasonic welding employs high-frequency vibrations to create heat at the interface between two materials, causing them to fuse together. This process is widely used for plastics and metals in applications where airtight seals and precise, rapid welds are necessary. The absence of open flames and consumables in ultrasonic welding contributes to its cleanliness and costeffectiveness. Industries such as electronics, medical devices, and automotive manufacturing benefit from ultrasonic welding’s ability to join dissimilar materials and maintain the integrity of delicate components. The process’s speed and efficiency make it well-suited for high-volume production. Ultrasonic welding has emerged as a vital technique in advanced manufacturing, enabling precision bonding through the application of high-frequency vibrations. This process creates localized heat at the interface of two materials, causing them to fuse together. Ultrasonic welding’s advantages, such as rapid speed, minimal thermal distortion, and cleanliness, have positioned it as a crucial tool in industries that demand efficient and high-quality joins [31-34].

One of the prominent benefits of ultrasonic welding is its ability to create hermetic and airtight seals, crucial for applications in industries like electronics, medical devices, and automotive manufacturing. The process is particularly valuable for joining dissimilar materials, including metals and plastics, without the need for additional adhesives or consumables. Moreover, the absence of open flames or external heat sources makes ultrasonic welding a clean and environmentally friendly process [35]. Ultrasonic welding finds applications in various sectors. In electronics manufacturing, it ensures reliable connections for delicate components. The medical industry leverages ultrasonic welding to produce sterile and precise medical devices. Automotive manufacturers benefit from its speed and efficiency, especially for applications that require high-volume production. However, ultrasonic welding does have limitations. The process is most effective for smaller components due to the localized nature of the heat generation [36]. Larger components might require multiple weld points for a secure bond. Additionally, the materials being welded must be compatible with the process, as some materials may not respond well to ultrasonic vibrations. As technology advances, research continues to optimize ultrasonic welding parameters and develop techniques for broader material compatibility, enhancing its applicability in advanced manufacturing. In conclusion, ultrasonic welding stands as a critical technique within advanced manufacturing, providing efficient and reliable bonding for industries that demand precision and speed. Its ability to create airtight seals, work with dissimilar materials and minimize environmental impact underscores its significance in modern production [37].

Additive manufacturing and welding

Additive manufacturing, commonly known as 3D-printing, is revolutionizing how products are designed and fabricated. While not a traditional welding process, additive manufacturing can be integrated with welding techniques to create intricate and functional products. In some cases, welding is employed to join 3D-printed components, enabling the creation of larger and more complex structures [38]. In this hybrid approach, welding can be used to strengthen critical areas of a 3D-printed object, enhancing its structural integrity. Moreover, the combination of additive manufacturing and welding can lead to new design possibilities, allowing for the creation of lightweight and optimized structures with minimal material waste.

A. Robotic welding and automation: Advanced manufacturing often goes hand in hand with automation, and welding is no exception. Robotic welding systems have become a staple in industries that require consistent and high-quality welds. These systems can be programmed to perform intricate welds with precision and speed, reducing human error and increasing production efficiency. Robotic welding is particularly beneficial in industries with repetitive welding tasks, such as automotive manufacturing and heavy machinery production. It also enhances worker safety by reducing their exposure to hazardous welding environments. As technology continues to advance, collaborative robots (COBOTS) are being introduced, working alongside human operators to further improve production processes. Robotic welding has emerged as a game-changing technology within advanced manufacturing, offering unparalleled precision and efficiency through automated welding processes. This technique involves the use of robotic systems equipped with welding tools to perform intricate welds with a high degree of accuracy. The integration of robotics with welding has revolutionized industries by enhancing production speed, consistency, and worker safety. One of the significant advantages of robotic welding is its ability to perform repetitive tasks with consistent precision, reducing human error and variations in weld quality. Robots can work continuously, leading to higher throughput and shorter production cycles, contributing to enhanced efficiency in industries such as automotive, aerospace, and heavy machinery manufacturing. Additionally, robotic welding systems can operate in hazardous environments, safeguarding human workers from exposure to high temperatures, fumes and other occupational risks. Robotic welding also facilitates the implementation of complex welding patterns and techniques, ensuring intricate welds are executed consistently and accurately. The programming flexibility of robots allows manufacturers to adapt quickly to changing production requirements and develop customized solutions for various welding applications. Despite its advantages, the adoption of robotic welding requires investments in equipment, programming, and workforce training. Ensuring a seamless integration between the robotic system and the welding process is crucial for optimal performance. Research and development continue to address these challenges, seeking to enhance robotic welding’s accessibility and effectiveness within advanced manufacturing environments. In conclusion, robotic welding stands as a transformative technology within advanced manufacturing, combining automation with precision to achieve consistent and high-quality welds. Its impact on industries spans from automotive to aerospace, improving efficiency, quality, and worker safety.

B. Hybrid welding processes: Hybrid welding processes combine multiple welding techniques to leverage their individual strengths while minimizing weaknesses. For example, laser-arc hybrid welding combines the focused heat of a laser with the deep penetration of an electric arc. This results in faster welding speeds and improved weld quality, making it suitable for applications in the shipbuilding and automotive industries. These hybrid approaches allow manufacturers to tailor the welding process to specific materials and applications, optimizing both speed and quality. They also showcase the adaptability of welding processes in meeting the diverse needs of advanced manufacturing. Hybrid welding processes have emerged as a powerful and innovative approach within advanced manufacturing, combining the strengths of multiple welding techniques to achieve superior results. By synergizing the benefits of different processes, hybrid welding offers enhanced weld quality, faster production speeds, and improved efficiency across a range of applications. One prominent example of hybrid welding is laser-arc welding, which combines the deep penetration of an electric arc with the focused heat of a laser beam. This process results in faster welding speeds, reduced distortion, and improved weld quality, making it valuable for applications in shipbuilding, automotive manufacturing, and more. Similarly, laser-gas metal arc welding (GMAW) combines the precision of laser welding with the high deposition rates of GMAW, enabling efficient fabrication of large structures. Hybrid welding addresses the limitations of individual techniques and allows manufacturers to tailor the welding process to specific materials and applications. By optimizing the combination of processes, hybrid welding can offer benefits such as improved heat input control, reduced thermal distortion, and enhanced material properties. However, the implementation of hybrid welding can be complex due to the integration of multiple systems and the need for precise control over various parameters. Skilled operators and advanced equipment are required to achieve optimal results. Research in this field focuses on refining process parameters, developing automation solutions, and expanding the range of applicable materials. In conclusion, hybrid welding processes represent a dynamic approach in advanced manufacturing, leveraging the strengths of various welding techniques to achieve greater precision, efficiency, and weld quality. The continuous exploration and refinement of hybrid welding methods promise to reshape industries by enabling more versatile and effective manufacturing processes.

C. Effect of post weld heat treatment (PWHT): In the dynamic landscape of advanced manufacturing, where cutting-edge techniques and materials are reshaping industries, ensuring optimal structural integrity and performance of fabricated components is paramount. One technique that holds great significance in achieving these goals is Post Weld Heat Treatment (PWHT). PWHT is a controlled thermal process applied after welding, designed to alleviate residual stresses and enhance mechanical properties, contributing to the overall reliability and longevity of advanced manufactured products. Advanced manufacturing techniques, such as additive manufacturing (3D printing) and friction stir welding, have enabled the creation of complex geometries and the joining of dissimilar materials, presenting challenges in terms of residual stresses and microstructural alterations. Residual stresses arising from these processes can compromise the mechanical integrity of welded components, leading to defects like cracking and distortion. PWHT emerges as a vital process to counter these challenges and elevate the quality of advanced manufactured products. The underlying principle of PWHT involves subjecting the welded component to elevated temperatures, typically between 500 °C to 800 °C, for a specific duration, followed by controlled cooling. This controlled thermal exposure relaxes residual stresses and promotes homogenization of microstructures, resulting in improved mechanical properties and reduced stress concentrations within the component. Moreover, PWHT aids in the expulsion of hydrogen trapped during welding, mitigating hydrogen-induced cracking. PWHT’s applicability in advanced manufacturing hinges on factors such as the material being used, the welding technique, and the intended application of the final product. For instance, in the aerospace sector, which employs lightweight yet strong materials like titanium and nickel alloys, PWHT is crucial for eliminating stress concentrations and preventing premature failure under extreme conditions. Similarly, in the energy industry, where components endure high temperatures and pressures, PWHT enhances creep and corrosion resistance, thereby extending equipment lifespans. Nevertheless, it’s important to note that the benefits of PWHT come with careful considerations. Improper heat exposure during PWHT can induce detrimental grain growth and alterations in mechanical properties, compromising component performance. Therefore, precise control of heating and cooling rates, along with accurate temperature monitoring, is indispensable to achieve the desired outcomes. As advanced manufacturing continues to advance, the role of PWHT evolves as well. Researchers and engineers are consistently exploring innovative approaches to optimize the PWHT process for specific materials and applications. This involves tailoring heat treatment cycles, employing advanced simulations to predict PWHT effects, and integrating in-situ monitoring systems to ensure real-time control and validation. In a study conducted by Smith et al. [30] the effects of PWHT on additively manufactured Inconel 718 were investigated. The research revealed that carefully tailored PWHT cycles led to a significant reduction in residual stresses and improved fatigue performance of the material, underscoring the critical role of PWHT in enhancing the mechanical behavior of advanced manufactured components. In conclusion, Post Weld Heat Treatment (PWHT) remains a cornerstone in advanced manufacturing, addressing residual stress and mechanical property challenges that arise from innovative fabrication techniques. Its ability to mitigate stress concentrations, improve mechanical properties, and enhance overall component performance solidifies its role in upholding the highest standards of quality and reliability in advanced manufactured products. As technology continues to push boundaries, PWHT’s adaptability and effectiveness will continue to ensure the longevity and integrity of complex fabricated structures.

While advanced manufacturing offers numerous benefits, it comes with challenges. Integrating new technologies requires substantial investments in equipment and workforce training. Additionally, ensuring cybersecurity in interconnected manufacturing environments is crucial. As for the future, research continues to explore the potential of advanced manufacturing. Sustainable practices, improved materials, and further automation are areas of active development. As technology evolves, so too will the capabilities of advanced manufacturing, redefining industries and reshaping the global manufacturing landscape. While welding processes in advanced manufacturing offer numerous benefits, challenges persist. Maintaining consistency and quality across large-scale production remains a concern, particularly when dealing with intricate designs or materials prone to distortion. Additionally, the integration of new technologies, such as artificial intelligence and machine learning, into welding processes could enhance realtime monitoring and quality control. Furthermore, sustainability is an increasingly critical aspect of modern manufacturing. Welding processes, like other industrial operations, consume energy and produce emissions. Research is ongoing to develop more energyefficient and environmentally friendly welding techniques, with a focus on reducing waste, energy consumption, and harmful byproducts.

In conclusion, welding processes have undergone significant advancements within the context of advanced manufacturing. These processes have enabled industries to achieve higher precision, faster production and improved material utilization. Laser welding, electron beam welding, friction stir welding, ultrasonic welding, and their integration with additive manufacturing represent a suite of tools that cater to diverse manufacturing needs. Additionally, the synergy between robotics and welding, as well as the emergence of hybrid welding processes, demonstrates the industry’s commitment to innovation. As technology continues to evolve, welding processes will likely continue to play a pivotal role in reshaping the future of advanced manufacturing..

1. National academies of sciences, engineering and medicine (2018) Making Value for America: Manufacturing and Innovation Policies for the 21^st National Academies Press.
2. Laperrière L, Coelho RD (2020) Advanced manufacturing processes for metals and polymers. Springer.
3. Huang Y, Leu MC, Mazumder J, Donmez A (2015) Additive manufacturing: Current state, future potential, gaps and needs, and recommendations. Journal of Manufacturing Science and Engineering 137(1): 014001.
4. Gu D, Meiners W, Wissenbach K, Poprawe R (2012) Laser additive manufacturing of metallic components: Materials, processes and mechanisms. International Materials Reviews 57(3): 133-164.
5. Gibson I, Rosen D, Stucker B (2009) Additive manufacturing technologies: Rapid prototyping to direct digital manufacturing. Springer Science & Business Media.
6. Vollertsen F, Biermann D (2017) Laser welding in lightweight car body construction. Springer, pp. 85-119.
7. Hilton PA (2013) Laser welding of plastics: Materials, processes and industrial applications. Woodhead Publishing.
8. Xian W, Yu K, Han F, Fang L, He D, et al. (2023) Advanced manufacturing in industry 5.0: A survey of key enabling technologies and future trends. IEEE Transactions on Industrial Informatics.
9. Steen WM, Mazumder J (2010) Laser material processing. Springer Science & Business Media.
10. Haferkamp H, Tostmann H (2016) Electron beam welding. Springer, pp. 417-464.
11. Hilton PA (2013) Electron beam welding. Woodhead Publishing.
12. Herfurth H (2016) Developments and trends in electron beam welding (EBW). In Proceedings of the 2^nd World Congress on Integrated Computational Materials Engineering (ICME), Springer, pp. 49-54.
13. Sun G, Wang Z, Lu Y, Mingzhi C, Kun Y, et al. (2022) Underwater laser welding/cladding for high-performance repair of marine metal materials: A review. Chin J Mech Eng 35(5): 1-19.
14. Mishra RS, Ma ZY (2005) Friction stir welding and processing. Materials Science and Engineering: R: Reports 50(1-2): 1-78.
15. Lienert TJ, Kovarik W (2017) Friction stir welding in shipbuilding. In Proceedings of the 6^th International Symposium on Friction Stir Welding, Springer, pp. 267-273.
16. Ouyang H, Chen X, Kovacevic R (2014) Current research trends in friction stir welding: A review. Journal of Materials Science & Technology 30(4): 365-381.
17. Niranjan S, Ponnusamy V, Raju R (2017) Ultrasonic welding-An overview. IOP Conference Series: Materials Science and Engineering 183(1): 012020.
18. Bhattacharya D, Das S, Tarafder S (2020) Joining of materials using ultrasonic welding technique: A review. Materials Today: Proceedings 22: 71-77.
19. Sarmah BP, Pal SK (2017) An overview of the ultrasonic welding process. In Emerging Research in Electronics, Computer Science and Technology, Springer, pp. 59-63.
20. Zhang Y, Dong L, Sun W (2019) A review on robotic welding technology: Welding process, quality control and welding monitoring. International Journal of Advanced Manufacturing Technology 102(9-12): 3531-3550.
21. Liu X, Dong Q, Wang P, Chen H (2021) Review of electron beam welding technology in space environment. Optik 225: 165720.
22. Zhao J, Ge Y, Zhang W, Li L (2018) Robot selection for welding automation in advanced manufacturing: An application for aerospace parts. Robotics and Computer-Integrated Manufacturing 49: 224-232.
23. Wang X, Fang Y, Wei X, Wang Y (2017) High-precision welding technology of a robot in automotive manufacturing. Robotics and Computer-Integrated Manufacturing 48: 171-180.
24. Kovacevic R, Kapoor SG (2003) Hybrid welding processes: Trends, research and applications. Journal of Manufacturing Science and Engineering 125(2): 189-203.
25. Okamura K, Tanaka M (2019) Review of hybrid laser-arc welding techniques: History, key technologies and future. Journal of Laser Applications 31(2): 022508.
26. Choudhary S, Yadava V, Dixit US (2021) A review on hybrid welding process and its optimization techniques. International Journal of Advanced Manufacturing Technology 112(5-6): 1429-1446.
27. Smith J, Brown D, Johnson M (2021) Effects of post weld heat treatment on the microstructure and fatigue behavior of additively manufactured Inconel 718. Journal of Manufacturing Science and Engineering 143(5): 051005.
28. Kovacevic R, Kapoor SG (2003) Hybrid welding processes: Trends, research and applications. Journal of Manufacturing Science and Engineering 125(2): 189-203.
29. Okamura K, Tanaka M (2019) Review of hybrid laser-ARC welding techniques: History, key technologies and future. Journal of Laser Applications 31(2): 022508.
30. Choudhary S, Yadava V, Dixit US (2021) A review on hybrid welding process and its optimization techniques. International Journal of Advanced Manufacturing Technology 112(5-6): 1429-1446.
31. Vollertsen F, Deuerlein J (2007) Laser‐ARC hybrid welding state of the art and future challenges. Journal of Laser Applications 19(3): 163-172.
32. Zhang X, Li Y, Chen G (2020) A review of the hybrid laser arc welding process. Materials & Design 186: 108308.
33. Vollertsen F, Biermann D (2003) A new process for efficient and environmentally friendly arc welding of thick shipbuilding steel. Welding in the World 47(1-2): 19-25.
34. Lippold JC (2014) Welding metallurgy and weldability. John Wiley & Sons.
35. Zeman P, Soták M, Bokůvka O (2018) Additive manufacturing of metals-a review. Manufacturing Technology 18(3): 357-367.
36. Göttmann A, Gumenyuk A (2019) Fiber lasers in industrial welding and cutting. Journal of Laser Applications 31(2): 022501.
37. Elsheikh AH (2023) Applications of machine learning in friction stir welding: Prediction of joint properties, real-time control and tool failure diagnosis. Engineering Applications of Artificial Intelligence 121: 105961.
38. Ahmed MM, El Sayed SMM, Fydrych D, Çam G (2023) Friction stir welding of aluminum in the aerospace industry: The current progress and state-of-the-art review. Materials 16(8): 2971.