Julie Tucker

Profile Information
Dr. Julie Tucker
Oregon State University
Associate Professor
Oregon State University
Ab Initio Modeling, Welding
"Effect of stoichiometry on the evolution of thermally annealed long-range ordering in Ni-Cr alloys" David Sprouster, Fei Teng, George Young, Jia-Hong Ke, Julie Tucker, Materialia Vol. 8 2019 100453 Link
Ni-based alloys, such as alloys 690 and 625, are widely used in the nuclear industry as structural components, because of their desirable mechanical properties and resistance to stress corrosion cracking. However, in some high chromium alloys, a disorder-order phase transformation near 33 at.% Cr, is known to decrease ductility and fracture toughness. In this study, the ordering transformation is investigated in Ni-Cr binary model alloys to better understand the effects of composition. Model alloys with different stoichiometries (Ni/Cr = 1.8, 2.0, 2.2, 2.4) were isothermally aged up to 10,000 h at three temperatures (373°C, 418°C, and 475°C) and characterized by transmission electron microscopy (TEM), microhardness, and synchrotron-based X-ray diffraction (XRD). TEM results show the evolution of the Ni2Cr (MoPt2-type) ordered precipitates between 3,000 h and 10,000 h with corresponding size of ∼10 nm to 20 nm. Microhardness testing results show that off-stoichiometry (Ni/Cr ≠ 2.0) alloys exhibit a smaller change with ordering compared to the stoichiometric (Ni/Cr = 2.0) alloy at all temperatures. XRD quantifies ordering induced lattice contraction in the matrix structure and the size of the ordered precipitates. No BCC Cr was detected by XRD or TEM during characterization in the range of 29.83 to 35.66 at.% Cr after 10,000 h of aging, confirming that all of the hardening can be attributed to the development of Ni2Cr in alloys ranging from Ni/Cr of 1.8 to Ni/Cr of 2.4.
"First-principles study of the products of CO2 dissociation on nickel-based alloys: Trends in energetics with alloying element" Julie Tucker, Surface Science Vol. 677 2018 219-231 Link
"Effect of isothermal and irradiation-induced long range ordering in Ni-Cr based commercial alloys" Julie Tucker, Emmanuelle Marquis, NuMat October 15-18, (2018)
"Effect of Thermal And Irradiation-induced Long Range Ordering in Ni-Cr Model Alloys" Fei Teng, David Sprouster, Peter Hosemann, Li-Jen Yu, Emmanuelle Marquis, Julie Tucker, NuMat October 14-18, (2018)
"Irradiation-accelerated phase transformations for low-temperature phase diagram development" Julie Tucker, Fei Teng, Emmanuelle Marquis, David Sprouster, MRS November 25-30, (2018)
"Role of aging and irradiation on ordering phase transformations in Ni-Cr alloys" Julie Tucker, Fei Teng, Emmanuelle Marquis, MRS Spring Meeting April 16-20, (2018)
"The Role of Ordering Phase Transformations in Micro-mechanics of Ni-Cr Alloys for Nuclear Applications" Fei Teng, Stephanie Pitts, Hi Vo, Peter Hosemann, Julie Tucker, TMS March 11-14, (2018)
NSUF Articles:
DOE Awards 33 Rapid Turnaround Experiment Research Proposals - Projects total approximately $1.2 million These projects will continue to advance the understanding of irradiation effects in nuclear fuels and materials in support of the mission of the DOE Office of Nuclear Energy. Monday, June 18, 2018 - Calls and Awards
DOE awards 39 RTE Projects - Projects total approximately $1.3 million Thursday, February 1, 2018 - Calls and Awards