Active Projects
Multi-Principle Element Alloys
In-situ transmission electron microscopy (TEM) ion irradiation serves as a critical characterization method in the nuclear materials community to decipher irradiation-induced defect formation in alloys and materials. Multi-Principal Element Alloys (MPEAs) are a new class of alloys with enhanced properties, including potentially enhanced irradiation resistance. In this work, the microstructure of an equiatomic HfNbTaZr MPEA under heavy ion irradiation is being studied at room temperature and 300 °C under ex-situ and in-situ TEM irradiation.
YHx for Microreactor Moderation
As energy demands increase, nuclear reactors, especially microreactors, become a promising energy source. These reactors run at high temperatures (>280°C), requiring moderators that can endure these environments. Yttrium hydride is a possible moderator, but little is known about the material’s phase stability and hydrogen retention under irradiation. Through the use of a gold ion beam, samples with stoichiometries ranging from 1.6 to 2.0 were irradiated and tested.
Corrosion of Laser Weldments
This study explores the impact of localized corrosion on the mechanical performance of laser-welded 316L SS using a sequential testing methodology. 316L SS is a common material choice for dry cask storage of nuclear waste. Many storage sites are located near chloride-rich environments where long-term exposure may induce Stress Corrosion Cracking (SCC). The welds on casks create a mechanical weak point due to the high temperatures and stresses during formation. Laser welds offer minimal sensitization and finer grain structures compared to traditional welding methods which may offer superior long-term corrosion resistance.
Fusion Divertor Materials Analyses
Refractory complex concentrated alloys (CCAs) may offer enhanced performance in the divertor region of a fusion reactor environment where plasma-facing materials will be subject to high temperatures, low energy He/D particles, and 14 MeV neutrons. In this work, specimens with the nominal composition of NbTaMoTi, NbTaMo, NbTaTi, and NbTa were fabricated via directed energy deposition (DED) and subsequently bombarded with 40 eV He ions at 1000 K. Post irradiation, the surface morphology and composition are being examined with electron microscopy and x-ray photoelectron spectroscopy to offer information on the spatial distribution of surface nano-structuring.