Books by Ajithkumar Sitharaj
Elsevier, 2025
In response to growing environmental concerns and the urgency to combat global warming, there has... more In response to growing environmental concerns and the urgency to combat global warming, there has been a notable shift toward eco-friendly biocomposites. Among these alternatives, root-based fiber–reinforced composites (RFCs) have gained significant attention due to their biodegradable and sustainable characteristics. Natural fibers derived from plant roots possess the benefits of abundant availability, cost-effectiveness in the harvesting process, and favorable mechanical properties. These composites exhibit desirable traits such as degradability, renewability, nonabrasiveness, and nontoxicity. Additionally, they demonstrate comparable properties to synthetic fiber composites, enabling extensive applications across diverse fields. However, root-based fibers have certain limitations, including high moisture absorption, poor fire resistance, swelling and degradation, nonhomogeneity of mechanical characteristics, and inadequate interfacial interactions with polymeric matrices. Surface functionalization of the fibers using various approaches, such as physical and chemical treatments, offers a potential solution to overcome these drawbacks, particularly by improving the compatibility of the fiber with the polymeric matrix. This chapter presents commonly employed methods for the modification of root-based fibers and their applications. Additionally, the chapter delves into the future prospects of RFCs through a comprehensive patent landscape analysis. The analysis provides insights into the potential advancements and opportunities in this field by examining patent trends, technological clusters, and emerging research areas.
Elsevier, 2024
Mineral fiber composites have garnered widespread use in diverse industries due to their exceptio... more Mineral fiber composites have garnered widespread use in diverse industries due to their exceptional properties compared with other fibers. These composites find applications in electronics, aviation, medical, maritime, automotive, and concrete structures, boasting advantages such as strength, durability, and lightweight properties. However, their production and disposal pose significant environmental challenges. The energy-intensive manufacturing processes involving fiber extraction, processing, and composite fabrication, contribute to environmental impacts. Furthermore, the nonbiodegradable nature of these composites raises concerns during disposal. To address these environmental issues, life cycle assessment (LCA) studies are conducted, thoroughly analyzing all life cycle stages, from raw material extraction to end-of-life disposal, to assess the environmental footprint of mineral fiber composites. This chapter explores the comprehensive LCA and environmental impact assessment studies on mineral fibers and their composite manufacturing processes. It provides invaluable insights into the environmental performance of mineral fiber composites, enabling the formulation of strategies to minimize their negative effects and foster more sustainable practices in their production and utilization.
taylor and francis, 2025
ABSTRACT
The Wire and Arc Directed Energy Deposition (WA-DED) process is an ideal method for addi... more ABSTRACT
The Wire and Arc Directed Energy Deposition (WA-DED) process is an ideal method for additive manufacturing (AM) of sizable metallic parts. It offers a higher deposition rate, material efficiency, and shorter lead times than powder-based AM methods. Titanium alloys have gained significant importance across aerospace, biomedical, and automotive sectors due to their outstanding mechanical characteristics, lightweight nature, corrosion resistance, and biocompatibility. Specifically, β-titanium alloys that exhibit a lower modulus when compared to human bone have been increasingly employed in the field of biomedical applications. In contrast, α and α+β titanium alloys find favor in automotive and aerospace industries due to their lightweight attributes. However, conventional manufacturing faces challenges, particularly in producing intricate, massive titanium components with a high buy-to-fly ratio. Consequently, WA-DED has emerged as a leading solution, capable of producing large-scale and near-net-shape titanium alloy parts. This chapter discusses recent advancements in WA-DED for titanium alloys and explores its promising future potential.
Wiley, 2025
Hybrid welding is a specially developed manufacturing process where two or more forms of welding ... more Hybrid welding is a specially developed manufacturing process where two or more forms of welding are combined to derive maximum benefits from each of their characteristics. The most common form of hybrid welding uses the combination of laser with arc welding. This chapter addresses the current status, progress, and applications of hybrid laser arc welding (HLAW) technology. It is the simultaneous use of laser and arc welding techniques that gives faster welding speeds compared to when one uses either technology. The laser provides a deep penetration, and the arc welding fills up the junction properly to provide strength and excellent weld. The concentrated thermal energy provided by the laser drastically reduces the overall extent of the heat-affected zone, which consequently results in an enormous decrease in thermal distortion and residual stresses at the welded regions. This process produces welds with very high mechanical properties and lower possibilities of defects like porosity and cracking. HLAW finds massive applications across various industries. The automotive industry applies it to make lightweight highly strength-to-weight-proportioned components. Shipbuilding industries use this process in joining heavy plates without the distortion of members. The aerospace industries apply it in making highly critical structural components. It is also used in the construction and energy industries in the construction of strongly base metal structures and pipelines.
Papers by Ajithkumar Sitharaj
Metal additive manufacturing is experiencing rapid growth due to its ability to produce intricate... more Metal additive manufacturing is experiencing rapid growth due to its ability to produce intricately designed parts with customized features for diverse applications. However, the as-built configuration of these parts often exhibits insufficient and poor surface quality. Various imperfections and defects, such as the staircase effect resulting from layer-by-layer deposition, partially fused feedstock material, spatters, balling effects, and inadequate fusion, contribute to notably irregular surface morphology. This elevated surface roughness poses a significant challenge, limiting the potential applications of additive manufactured parts in areas such as fatigue performance, dimensional accuracy, wear and scratch resistance, and aesthetics. In response to these challenges, the manufacturing landscape is transforming by introducing Hybrid Additive Manufacturing (HAM) processes. These processes aim to minimize manufacturing costs while enhancing mechanical properties and surface quality by integrating additive manufacturing with conventional production methods. HAM represents a synergistic blend of techniques, producing a cumulative effect greater than the sum of its individual processes. Hence, this paper offers a comprehensive review of the current state and future prospects of hybridization in metal additive manufacturing, shedding light on innovative strategies to overcome surface quality limitations and optimize the overall performance of additively manufactured parts.
Springer, 2025
Wire arc directed energy deposition (WA-DED) of titanium alloys represents a cutting-edge and ver... more Wire arc directed energy deposition (WA-DED) of titanium alloys represents a cutting-edge and versatile additive manufacturing process that has garnered attention for its efficiency, cost-effectiveness, and applicability to large-scale production. In comparison to traditional subtractive manufacturing methods, WA-DED's layer-by-layer additive process significantly reduces lead times. Titanium alloys are particularly well-suited for WADED due to their high strength-to-weight ratio, corrosion resistance, and suitability for aerospace and biomedical applications. However, adopting conventional WADED methods has faced challenges due to the increasing demand for intricate, high-quality products. The hybridization of the WADED approach combines traditional additive manufacturing methods with specialized techniques to address these challenges and optimize the production of components. Hence, this article explores the hybridization methods utilized in WADED for titanium alloys. Hybridization techniques contribute to the production of high-quality titanium alloy components with enhanced properties and functionality. Processes such as laser shock peening and ultrasonic impact treatment refine the microstructure, leading to improved mechanical properties and heightened performance in titanium alloy components. Precision control is achieved through techniques like CNC machining, ensuring that the deposited material adheres precisely to specified specifications. Laser shock peening aids in managing residual stresses within the manufactured components, a critical aspect of preventing deformation and cracking in titanium alloys. Hybridization facilitates more efficient material usage by incorporating methods like inter-pass cold rolling and hot wire, optimizing material deposition, minimizing waste, and reducing costs. Finally, the future scope of
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Books by Ajithkumar Sitharaj
The Wire and Arc Directed Energy Deposition (WA-DED) process is an ideal method for additive manufacturing (AM) of sizable metallic parts. It offers a higher deposition rate, material efficiency, and shorter lead times than powder-based AM methods. Titanium alloys have gained significant importance across aerospace, biomedical, and automotive sectors due to their outstanding mechanical characteristics, lightweight nature, corrosion resistance, and biocompatibility. Specifically, β-titanium alloys that exhibit a lower modulus when compared to human bone have been increasingly employed in the field of biomedical applications. In contrast, α and α+β titanium alloys find favor in automotive and aerospace industries due to their lightweight attributes. However, conventional manufacturing faces challenges, particularly in producing intricate, massive titanium components with a high buy-to-fly ratio. Consequently, WA-DED has emerged as a leading solution, capable of producing large-scale and near-net-shape titanium alloy parts. This chapter discusses recent advancements in WA-DED for titanium alloys and explores its promising future potential.
Papers by Ajithkumar Sitharaj