Projects

Development, Characterization and Performance Evaluation of Surface Engineered Additively Manufactured Parts for Nuclear Reactors (Funding Agency: National Science Foundation)

Metal additive manufacturing (AM) has developed significantly since its invention. In this project, laser-based directed energy deposition (DED) process will be utilized to fabricate metallic parts for nuclear reactor application. Post printing, the samples will be analyzed using neutron diffraction to reveal the evolution of microstructure, residual stress, and phase fractions at different build height regions along the build direction of fabricated samples to correlate the microstructural details with process conditions. Our research goal is to leverage this perspective to develop next-generation nuclear reactor components with enhanced reliability and customizability when encountering friction and wear at different temperatures. We will fabricate functionally graded metallic components made of Nitronic 60 stainless steel by leveraging customized laser-based directed energy deposition (DED) technique equipped with an ultrasonic impact peening (UIP) capability. Nitronic 60 is an inexpensive austenitic stainless steel widely used in the nuclear sector due to its galling-resistance properties. This material can present high-temperature wear and corrosion resistance, and widely used in valve seats, bushings, roller bearings, and rings. We believe that optimized process parameters during UIP treatment can result in a strain-induced FCC to HCP martensitic phase transformation (SIM) in the deposited near-surface layers of Nitronic 60, and enhanced materials states, such as residual stress with refined grains, can result in improved tribological behavior.