Doctor of Philosophy (PhD)
Department of Mechanical & Industrial Engineering
Additive manufacturing (AM) has gained attention in recent years due to its unique properties in the fabrication of complex parts. Same as any other new topics, in some areas, there is still a lack of enough knowledge and there is the need for further investigations to enable the applications of AM parts widely in industries. Chapter 2, and Chapter 5 to Chapter 8 of this report are focused on the corrosion properties of the parts and coatings fabricated using the laser powder bed fusion based AM method or laser surface processing method, including a comprehensive review. Laser powder bed fusion based AM was used to prepare copper alloy, titanium alloy, and stainless steel AM parts, and laser surface modification was performed on Fe-14Cr alloy.
The application of nickel superalloys is well known in various industries. Chapter 3, Chapter 9, Chapter 10 are a part of a DOE-funded project which has the final goal of producing Inconel 939 based superalloy parts with additive manufacturing method. The first step was to modify its composition to reach a better fatigue behavior (Chapter 9) with the help of phase composition and antiphase boundary energy associated with each phase. Since the lack of information about the hot corrosion properties of the newly designed alloys, the last chapter has been dedicated to evaluating Inconel 939 corrosion performance at elevated temperatures.
Hemmasian Ettefagh, Ali, "Corrosion Performance of Additively Manufactured Alloys and Hot Corrosion" (2021). LSU Doctoral Dissertations. 5452.