As a graduate student at Tech, I opted to complete a thesis; this was for Dr. Aaron Stebner at the Advanced Manufacturing Pilot Facility, investigating laser directed energy deposition methods for refractory alloy systems. If you'd like to read more than what's here, check out either my thesis or the article I published:
When I was in middle school, my parents gifted me a book called The Disappearing Spoon, authored by Sam Kean. In it, the hidden history of elements was unfolded, leaving me with a love for the elements; in particular, molybdenum stood out as my favorite. Years later, while searching for labs to complete my graduate thesis in, I heard of an opportunity to study additively manufacturing molybdenum. I jumped at the opportunity and found in it a great deal of interest and happiness. My two years in grad school consisted of learning a great deal about both additive manufacturing and molybdenum, which I will forever be grateful for.
The bulk of my research consisted of investigating methods of using the laser powder blown directed energy deposition manufacturing platform to create molybdenum samples, which then were characterized for microstructure, tensile strength, density, and much more. These efforts extended both into a pure molybdenum feedstock and one alloyed with lanthanum oxide, a common inoculant used to increase strength at elevated temperatures. During my team, I was able to gain a great deal of experience with laboratory devices, techniques, and results, that have since made me a much better engineer.Â
Spending two years learning about Mo taught me more about engineering and myself than I could possible write here. Notably, I am now considerably better at 3D printing and much more knowledgeable about materials and their characterization through laboratory equipment. A retrospective lens applied to my research yields an increase in understanding for experimental design and applying said design. I feel as if I matured greatly in this regard during my time. Personally, I think my motivations as an engineer clarified during my graduate tenure, leading me to enjoy bringing hard-to-manufacture physical products into the world.
(Above) Microstructures, via opitcal microscopy, of Molybdenum alloyed with various weight percents of lanthana, from 0% (a) to 3.5% (f); alloying yielded positive grain refinement results
(Top left) Optomec laser directed energy deposition platform, build plates, and nozzle
(Bottom left) Scanning electron microscopy (SEM) of alloyed powder
(Above) Observed lanthana additions in the microstructre of the deposited metal, under SEM (a/b) and optical (c/d) microscopy
(Left) 3D reconstruction of microstructure of hardness sample