Hahn Choo
University of Tennessee
Ultimate tensile strengthAmorphous metalNanocrystalline materialDeformation (engineering)CreepComposite materialMetallurgyGrain sizeMaterials scienceDiffractionShear bandAlloyResidual stressTexture (crystalline)Phase (matter)Amorphous solidNeutron diffractionPlasticityCrystallographyMicrostructure
231Publications
47H-index
5,225Citations
Publications 229
Newest
#1Rakesh R. Kamath (UT: University of Tennessee)H-Index: 1
#2Peeyush Nandwana (ORNL: Oak Ridge National Laboratory)H-Index: 19
Last. Hahn Choo (UT: University of Tennessee)H-Index: 47
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Abstract null null The effect of a spot melt strategy on the solidification texture, variant selection, phase fraction, and their variations along the build height was investigated in comparison to a conventional linear melt strategy. Ti-6Al-4V alloy samples were manufactured by an electron-beam powder bed fusion process using two different melt strategies and characterized using high-energy synchrotron x-ray diffraction. The linear and spot melt cases resulted in β null cube and fiber textures,...
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#1Michael C. Gao (DOE: United States Department of Energy)H-Index: 36
#2E-Wen HuangH-Index: 17
Last. Liang Jiang (Yantai University)
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#1Robert Minneci (UT: University of Tennessee)H-Index: 1
#2Eric A. Lass (UT: University of Tennessee)H-Index: 3
Last. Claudia J. Rawn (UT: University of Tennessee)H-Index: 35
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This review examines the development and current state of Cu-rich Cu–Cr–Nb alloys commonly referred to as GRCop or Glenn Research copper alloys with emphasis on Cu–8Cr–4Nb (at%), or GRCop-84, and C...
4 CitationsSource
#1Peijun Hou (UT: University of Tennessee)H-Index: 1
#2Yuan Li (UT: University of Tennessee)H-Index: 2
Last. Hahn Choo (UT: University of Tennessee)H-Index: 47
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Abstract null null The micromechanics of the formability of a lean duplex TRIP steel was investigated using Synchrotron X-Ray Diffraction (S-XRD) measurements and Crystal Plasticity Finite Element Modeling (CPFEM). Specifically, the effect of the ferrite phase on the reduction of stress concentrations in the martensite phase and the influence of the austenite texture on the distribution of the martensite phase in the deep-drawn duplex TRIP steel were studied in comparison to a TRIP steel case. A...
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#2Rakesh R. KamathH-Index: 1
Last. Zhenyu KongH-Index: 23
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Background/foreground separation is one of the most fundamental tasks in computer vision, especially for video data. Robust PCA (RPCA) and its tensor extension, namely, Robust Tensor PCA (RTPCA), provide an effective framework for background/foreground separation by decomposing the data into low-rank and sparse components, which contain the background and the foreground (moving objects), respectively. However, in real-world applications, the video data is contaminated with noise. For example, in...
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#1Bo Shen (VT: Virginia Tech)
#2Rongxuan Wang (VT: Virginia Tech)H-Index: 1
Last. Zhenyu Kong (VT: Virginia Tech)H-Index: 23
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Recent developments of advanced imaging systems spur their applications in many areas, ranging from satellite remote sensing for geographic information to thermal imaging analysis for manufacturing...
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#1Yuan Li (UT: University of Tennessee)H-Index: 2
#2Peijun Hou (UT: University of Tennessee)H-Index: 1
Last. Hahn Choo (UT: University of Tennessee)H-Index: 47
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Abstract Effect of dynamic recrystallization (DRX) on the grain refinement and texture modification was studied by conducting a series of hot compression on AZ31B Mg alloy. Processing-grain size-texture maps were established as a function of temperature, strain rate, strain, and the Zener-Hollomon parameter (Z). Moreover, influence of simultaneous changes in the grain size and texture on tensile yield strength and ductility of the hot-worked Mg alloy was studied using the grain size and texture ...
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#1Hahn Choo (UT: University of Tennessee)H-Index: 47
#2Logan P. White (UT: University of Tennessee)H-Index: 1
Last. E. Garlea (ORNL: Oak Ridge National Laboratory)H-Index: 8
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Abstract Tensile plastic deformation and fracture behavior of a laser powder bed fusion processed 316 L stainless steel alloy was investigated in situ using high-resolution synchrotron x-ray computed microtomography (sXCT). Three different cases were studied: (1) specimen A1, near full-density with initial porosity of 0.04%, (2) specimen B1, initial lack-of-fusion (LOF) porosity of about 3% with the major axis of defects aligned nearly perpendicular to the tensile loading direction (LD), and (3)...
1 CitationsSource
#1Peijun Hou (UT: University of Tennessee)H-Index: 1
#2Yuan Li (UT: University of Tennessee)H-Index: 2
Last. Hahn Choo (UT: University of Tennessee)H-Index: 47
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Abstract Constitutive micromechanical behavior of transformation induced plasticity (TRIP) stainless steel (SS) alloys was investigated using high-energy synchrotron x-ray diffraction (S-XRD) and in-situ neutron diffraction techniques. First, four different steel alloys were designed and produced: (1) a metastable austenitic TRIP SS, (2) a stable austenitic SS, which is a stable counterpart of the TRIP SS, (3) a lean duplex TRIP SS with ferrite and metastable austenite phases, and (4) a lean dup...
2 CitationsSource
#1Hahn Choo (UT: University of Tennessee)H-Index: 47
#2Michael Koehler (UT: University of Tennessee)H-Index: 15
Last. E. Garlea (ORNL: Oak Ridge National Laboratory)H-Index: 8
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Abstract The micromechanics of plastic deformation behavior of a selective laser melt processed austenitic stainless steel were studied by investigating the evolutions of texture and intergranular strain using in situ high-energy synchrotron x-ray diffraction (sXRD). The effects of defect characteristics on tensile behavior were studied using three different samples: a near full-density sample with elliptical closed voids and two samples with lack-of-fusion (LOF) defects tensile loaded either pe...
6 CitationsSource