Session: 03-03-04: Annual Congress-Wide Symposium on Additive Manufacturing IV

Paper Number: 166709

The Influence of Heat Input on Microstructure Properties of Wire Arc Additively Manufactured TI-6Al-4V Alloy 

Abstract:

Wire Arc Additive Manufacturing (WAAM) has emerged as a significant technology for the fabrication of titanium and its alloy components, particularly in the aerospace industry where weight reduction, high strength, and structural integrity are crucial factors. Titanium and its alloys are widely used in aerospace applications due to their excellent strength-to-weight ratio, corrosion resistance, and high-temperature performance. However, conventional manufacturing processes, such as machining and casting, are often associated with high costs, material wastage, and long production cycles, making them less productive and economically unviable for large-scale component fabrication. WAAM offers a viable alternative by utilizing a wire-based feedstock and an electric arc as a heat source to build components layer by layer. This additive approach significantly reduces material waste, lowers production costs, and shortens lead times, making it an attractive option for aerospace applications.

One of the major advantages of WAAM is its ability to produce large-scale components with near-net shape geometry, reducing the need for extensive post-processing. However, the mechanical properties and structural integrity of the deposited material are highly dependent on process control parameters, particularly heat input. The present study investigates the feasibility of applying WAAM for manufacturing titanium alloy components while examining the influence of heat input on microstructural properties and grain morphology. The results provide valuable insights into how process parameters can be optimized to achieve the desired mechanical performance.

The study reveals that heat input plays a critical role in determining the microstructural characteristics of the deposited titanium alloys. Specifically, variations in heat input directly impact the grain structure and anisotropic tensile properties of the components. At lower heat input levels, the deposits exhibit a mixture of prior-β grains, including both equiaxed and columnar grains, which are typically present in the middle region of the microstructure. This mixed grain morphology contributes to a more uniform distribution of mechanical properties across the component. In contrast, at higher heat input levels, the deposited material predominantly consists of larger columnar grains, resulting in anisotropic mechanical properties. The elongated columnar grains, oriented along the deposition direction, can lead to variations in strength and ductility, which must be carefully controlled to ensure reliable performance in aerospace applications.

Furthermore, the ability to manipulate heat input provides a means to tailor the microstructure and mechanical properties of WAAM-produced components. By adjusting process parameters such as voltage, current, and travel speed, it is possible to regulate the heat input and control grain growth, leading to improved performance and consistency in manufactured parts. This study highlights the importance of optimizing process conditions to achieve superior material properties, paving the way for the wider adoption of WAAM in aerospace manufacturing.

Keywords: Ti-6Al-4V; Wire arc additive manufacturing; Grain size; Columnar grains; Microstructure; Equi-axed grains; Cooling methods.

Presenting Author: Ragavanantham Shanmugam Fairmont State University

Presenting Author Biography: Dr. Ragavanantham Shanmugam currently serves as the Department Chair and Associate Professor of Engineering Technology at Fairmont State University. With over 25 years of academic and administrative experience spanning India and the United States, he has led programs in advanced manufacturing, mechanical engineering, and STEM education reform. Dr. Shanmugam’s leadership focuses on curriculum modernization, faculty development, and inclusive student engagement strategies, especially in underrepresented regions. He has secured over $10.9 million in research and educational funding from agencies such as NSF, NASA, DoE, and USDA. His recent initiatives explore AI-assisted learning analytics, structured student success pathways, and the intersection of workforce needs and academic innovation. Dr. Shanmugam is deeply committed to advancing meaningful, equity-driven change in engineering education and preparing the next generation of problem-solvers through real-world, data-informed teaching strategies.

Authors:

Muralimohan Cheepu Vitzronextech Co., Ltd
Ragavanantham Shanmugam Jacksonville State University
Lava Kumar Vandrangi Pepco Holdings