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4篇 您的检索式:作者名="Hengfei Gu"
    题名 作者 年代 出处 被引量
1The influence of microtexture on the formation mechanism of nodules in Zircaloy-4 alloy tube显示文摘Corrosion re sistance of Zircaloy-4 alloy tube in superheated steam at 673 K/10.3 MPa is anisotropic.A part of the surface undergoes uniform corrosion while the other suffers nodular corrosion.Narrow and wide nodules are observed after an exposure period of 3 and 30 days,respectively.A new matrix transformation method is established in order to study the formation mechanism of nodules in the cross-section(CS) of Zircaloy-4 alloy tube using the EBSD technique,while the CS perpendicular to axial direction(AD).The results reveal that the microtexture is a key factor behind the two types of corrosion.Furthermore,the oxide layers grow anisotropically over the corroded surface.A thick oxide layer forms over the nodular corrosion region on the grains with c-axis oriented in the range of 40° around tangential direction(TD),whereas a thin oxide layer over the uniform corrosion region is detected on the grains with c-axis oriented in the range of 68° around TD.In short,the anisotropic growth of oxide layer was caused by the change of microtexture of the Zr-4 alloy tube,and this anisotropic growth of oxide layer contributed to the nodules formation.Yingdong Zhang Fusen Yuan Fuzhou Han Muhammad Ali Wenbin Guo Geping Li Chengze Liu Hengfei Gu 2020Journal of Materials Science & Technology2020,47,12:2
2Nano-refinement of the face-centered cubic Zr(Fe,Cr)_(2)secondary phase particles in Zircaloy-4 alloy via localized-shearing/bending-driven fracture under high-temperature compression显示文摘Nanoparticles are extensively introduced to improve the mechanical,physical,and chemical properties of alloys.In the present study,the underlying nano-refinement mechanisms of face-centered cubic Zr(Fe,Cr)_(2)secondary phase particles(SPPs)that precipitated in Zircaloy-4 alloy under high-temperature compression were investigated in detail by utilizing high-resolution transmission electron microscopy(HRTEM)and conventional TEM techniques.The frequently observed Zr(Fe,Cr)_(2)SPPs were incoherent with the matrix and exhibited brittle fracture behaviors without measurable plasticity.HRTEM observations revealed two mechanisms underlying the nano-refinement of incoherent micro-sized SPPs via localized shear fracture on{11¯2}SPP and nanoprecipitate-assisted bending fracture,respectively.The latter was,for the first time,found to occur when the movements of large SPPs were blocked by nanometer-sized SPP during alloy deformation.Accordingly,two force models were proposed to visualize their potential nano-refinement processes.The knowledge attained from this study sheds new light on the deformation behaviors of Zr(Fe,Cr)_(2)SPPs and their associated size refinement mechanisms under high-temperature compression,and is expected to greatly benefit the process optimization of zirconium alloys to achieve precipitate nano-refinement.Fuzhou Han Geping Li Fusen Yuan Wenbin Guo Jie Ren Qichen Wang Yingdong Zhang Ali Muhammad Chengze Liu Hengfei Gu 2023Journal of Materials Science & Technology2023,,34:0
3A new type face-centered cubic zirconium phase in pure zirconium显示文摘So far,only two orientation relationships(OR)between hexagonal close-packed(HCP)(αphase)and facecentered cubic(FCC)structures in zirconium and titanium alloys have been reported.Here a new type FCC phase(named γ phase)with OR:<11■0>_(α)‖<100>_(γ) and{0001}_(α)‖{002}_(γ) was observed for the first time in annealed pure zirconium by means of transmission electron microscopy(TEM)technique.The α→γ phase transformation can be accomplished via expansion along[1■00]direction and slip of Shockley partial dislocation with 1/3[1■00]on(0001)basal planes.Fusen Yuan Geping Li Fuzhou Han Yingdong Zhang Ali Muhammad Wenbin Guo Jie Ren Chengze Liu Hengfei Gu Gaihuan Yuan 2021Journal of Materials Science & Technology2021,,22:0
4Deformation twinning in octahe dron-base d face-centere d cubic metallic structures:Localized shear-force dipoles drive atomic displacements显示文摘Twinning is found to impart favorable mechanical,physical and chemical properties to nanostructured materials.Deformation twinning prevails in face-centered cubic(FCC)nanocrystalline materials upon loading.In FCC structures,the<112>{111}deformation twinning is traditionally believed to nucleate and grow through layer-by-layer emission of 1/6<112>Shockley partial dislocations on consecutive{111}planes.We report that deformation twinning is able to occur in crystalline(Fe,Nb)_(23)Zr_(6)nanoparticles(NPs)that have a large Mn 23 Th 6-type FCC structure with a Zr-octahedron as a motif.Based on direct atomic-scale observations,we discover a new zero-net-strain path for the<112>{111}deformation twin-ning in FCC structures.To form a[¯1¯12]/(111)twin,for example,short(¯1¯11)planes within two adjacent(111)plane layers in the repeated three-layer sequence of(111)planes are shear deformed continuously by a shear-force dipole along the[11¯2]direction like a domino effect,whereas the other(111)plane in the repeated sequence remains intact.In addition,a loading criterion for deformation twinning of a FCC NP under uniaxial compression is proposed based on our observations.Our work here not only extends the fundamental understanding on deformation twinning in FCC structures,but also opens up studies of deformation behaviors in a class of Mn 23 Th 6-type FCC materials.Hengfei Gu Chengze Liu Fusen Yuan Fuzhou Han Yingdong Zhang Muhammad Ali Wenbin Guo Jie Ren Lifeng Zhang Songquan Wu Geping Li 2022Journal of Materials Science & Technology2022,,31:0
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