Doctor of Philosophy (PhD)


The Department of Mechanical & Industrial Engineering

Document Type



Additive Manufacturing (AM) has gained attention in recent years due to its unique capabilities in the fabrication of complex parts. As with any new research, there is still a lack of sufficient understanding in the field of additive manufacturing, and further investigation is needed to solve existing problems. Ultimately, the aim is to enable the widespread use of AM components across various industries.

Chapter One provides a brief introduction to the background and current bottlenecks of additive manufacturing technology. Chapter two focuses on the development of high-strength 7075 aluminum alloy (Al7075) for Fused Deposition Modeling and Sintering (FDMS) technology. Al7075 alloy is renowned for its excellent strength-to-weight ratio and mechanical properties. In this chapter, the aim is to explore the feasibility of using FDM to print Al7075 alloy. The main objective of this research is to simulate various forming processes of FDM technology using conventional powder metallurgy techniques to determine the sintering performance and strength of FDM-printed parts. The main focus of chapters three and four chapters is the investigation of the application of Laser Powder Bed Fusion (L-PBF) technology in Inconel 939 alloy (IN939). IN939 alloy is a high-temperature nickel-based alloy widely used in industries such as aerospace and gas turbine engines due to its excellent high-temperature strength, corrosion resistance, and oxidation resistance. The research conducted in these chapters aims to deepen the understanding of the feasibility and limitations of applying laser powder bed fusion technology to IN939 alloy. It also serves as a theoretical foundation and experimental guide for the practical utilization of this technology in high-temperature alloy fields, particularly in aerospace and gas turbine engine applications. Chapter five presents the overall conclusions of the key findings and insights obtained throughout the research and outlines the future research work about Additive Friction Stir Deposition (AFS-D) that needs to be pursued.



Committee Chair

Guo, Shengmin