Joining Operations for Aerospace Materials

Inhaltsverzeichnis

1. Frontmatter

2. Chapter 1. Adhesive Bonding Operations for Aeronautical Materials

   Fermin Bañon, Carolina Bermudo, Francisco Javier Trujillo, Sergio Martin-Béjar, Manuel Herrera, Lorenzo Sevilla

   Abstract

   This chapter provides an overview of adhesive bonding operations for aeronautical materials, which play a crucial role in joining aircraft components. It begins by discussing the predominant materials used in aircraft structures, including aluminum, titanium, and composite materials, while also examining their advantages and limitations in aircraft manufacturing. Emphasis is placed on bonding technologies, underscoring their significance in effectively joining diverse materials, particularly in the context of hybrid structures. The chapter also focuses on the analysis of various industrial adhesives, such as rigid and tacky types, highlighting their applications and the challenges they present. Furthermore, surface activation methods for these materials are explored in detail, discussing the impact of different treatments on surface wettability and adhesion. The chapter underscores the importance of accurate surface preparation, underscoring its role in enhancing the durability and reliability of adhesive bonds in aerospace applications.

3. Chapter 2. Riveted Joints in Aircraft Structures

   Mohammad Rauf Sheikhi, Melih Cemal Kuşhan, Selim Gürgen

   Abstract

   Joining methods are widely used in the applications of aerospace industries. The aircraft structure consists mainly of assemblies that need various ways to join them to achieve the required functions. Riveted joints have many benefits and remain popular in classic and modern aircraft structures. They can resist vibration, heat, and pressure expansion better than other joints, especially on the thin, delicate sheet metal often used to build aircraft. This chapter investigates the riveted joints in aircraft structures. The chapter provides an overview of different joining methods and their significance for aircraft structures. It then describes the typical riveted joints in aircraft assemblies and their classifications. It also gives a brief description of the modern processing techniques in riveted joints. After that, it discusses the factors that affect the damage to riveted joints. Finally, a case study is presented on single-riveted and double-riveted joints, connecting aerospace-grade aluminum alloys as well as being compared with an adhesively bonded joint as an alternative to riveted joints.

4. Chapter 3. Bolted Joints in Aerospace Structures

   Ömer Yay, Gökhan Kunt, Selim Gürgen

   Abstract

   Bolted joints are significantly important for the structural integrity, performance, and safety of aerospace structures since they are highly preferred for assembling the aerospace structures. For this reason, a careful approach is required for designing reliable joints in the aerospace industry. In this chapter, bolted joints in aerospace structures are discussed. Materials and surface treatments are given for the bolts used in the aerospace sector while mainly focusing on the bolt design by discussing the joining mechanisms and common failure modes in bolted joints.

5. Chapter 4. Brazing of Materials for Aerospace Applications

   Sónia Simões

   Abstract

   Developing joining technologies to produce advanced components with unique properties is attracting attention for aerospace applications. Brazing is one of the most reliable processes for the aerospace industry to obtain sound joints between dissimilar materials. This process takes place within a vacuum furnace or under controlled atmospheric conditions to produce strong bonds with notable resistance against corrosion and oxidation. This chapter presents the latest approaches to brazing similar and dissimilar materials for aerospace applications. The selection of brazing alloys is an essential step in this process. As such, the commonly used brazing alloys, such as those based on titanium or silver, and the new alloys being developed in this field will also be presented. Emphasis is placed on self-propagating high-temperature systems, nanomaterials, composite fillers, and amorphous filler metals.

6. Chapter 5. Numerical Simulation of Fusion Welding Processes

   F. A. O. Fernandes, A. B. Pereira, M. C. Silva

   Abstract

   This chapter is dedicated entirely to the numerical simulation of fusion welding processes. Initially, it introduces numerical simulation by discussing its historical background, fundamental concepts, and limitations. It thoroughly examines various types of analyses and models, focusing particularly on mechanical, thermal, and metallurgical aspects. Additionally, it discusses two types of heat source models along with their parameters and heat distribution mechanisms. The concept of mesh discretization and the available elements for it are also addressed. Finally, it briefly discusses the existing software for such simulations.

7. Chapter 6. Gas Tungsten Arc Welding Joints: Impact of Post Weld Heat Treatment (PWHT) and Nitrogen Addition in Shielding Gas

   Ali Tahaei, Behrouz Bagheri Vanani, Mahmoud Abbasi

   Abstract

   In this study, the UNS S32304 duplex stainless steel was welded by gas tungsten arc welding. The influences of the post weld heat treatment (PWHT) and the nitrogen addition to the shielding gas on the microstructure evolution, ferrite/austenite ratio, and mechanical characteristics of weld joints were investigated. Microstructural investigation showed the presence of coarse austenite laths with smoother boundaries with the matrix. From the results, the austenite and ferrite were observed with no evidence of undesired intermetallic phases. The phase percentage indicated that the best result for reaching an equivalent percentage of austenite and ferrite phases was obtained after using nitrogen gas and PWHT. It was concluded that specimens with the addition of nitrogen gas followed by PWHT show the highest mechanical characteristics among the conditions. The fracture surface of the specimen with the addition of nitrogen shows a small dimple size and a high percentage of separated voids while that after PWHT depicted relatively large dimples.

8. Chapter 7. Laser Welding of Lightweight Alloys

   Anika Akther, Nahiyan Kabir, Mobasher Hossain Takib, Sazedur Rahman, Md Enamul Hoque

   Abstract

   In this modern era, the importance of using light alloys in various manufacturing sectors such as automotive, military, biomedical, and aerospace has significantly increased. This is primarily due to their cost-effectiveness and favorable processing characteristics, including resistance to failure and high plasticity. The growing demand for lightweight structures made from materials like aluminum, magnesium, and titanium necessitates efficient machining methods that are also sustainable. To meet this demand, a range of versatile manufacturing techniques have been adopted, including alloying mixtures, friction stir welding, bulk deformation, surface modification methods, and additive manufacturing. Among these methods, laser welding has gained popularity in numerous studies due to its ability to handle high strain rates, fabrication complexities, wear, and collisions. Laser welding stands out for its capacity to bond thinner materials without the need for filler, thereby sustaining tensile and bending strength without excessive material usage. This is achieved through the electromagnetic heat and radiation emitted by the laser, which simultaneously enhances strength. This study focuses on the elaborate discussion of laser welding, which includes the benefits of laser welding over other conventional welding methods and its application in different types of alloys.

9. Chapter 8. Friction Stir Welding for Aerospace Alloys

   I. Del Sol, J. Salguero, M. Batista, A. Astarita, J. M. Vázquez

   Abstract

   Friction stir welding (FSW) has gained prominence as a transformative welding technique, especially for aerospace alloys, owing to its inherent advantages over conventional fusion welding methods. FSW offers distinct advantages, including minimized thermal distortion, improved mechanical properties, and a reduced heat-affected zone, addressing the challenges posed by traditional welding methods. Focused primarily on metals alloys and composites, this study explores the main process parameters, tool materials, and design considerations, critical for achieving superior weld quality and mechanical performance. This chapter investigates into the microstructural evolution during FSW, emphasizing the impact of welding parameters on grain refinement and defect mitigation. The study also discusses recent advancements in tool design and process optimization techniques to enhance the efficiency and reproducibility of FSW in aerospace manufacturing.

10. Backmatter