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Mass transport in a highly immiscible alloy on extended shear deformation

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Journal of Materials Science & Technology 2023年第3期134卷 197-208页

作者： Miao Song Jia Liu Xiaolong Ma Qin Pang Matthew J.Olszta Joshua Silverstein Madhusudhan R.Pallaka Peter V.Sushko Suveen N.Mathaudhu Cynthia Powell Arun Devaraj Bharat Gwalani Physical and Computational Sciences Directorate Pacific Northwest National Laboratory902 Battelle BoulevardRichlandWA 99354USA Energy and Environmental Directorate Pacific Northwest National Laboratory902 Battelle BoulevardRichlandWA 99354USA Material Science and Engineering Program University of CaliforniaRiversideCA92521USA Colorado School of Mines 1500 Illinois St.GoldenCO 8040USA Department of Materials Science and Engineering North Carolina State UniversityRaleighNC27695-7907USA State Key Laboratory of Powder Metallurgy Central South Uni-versityChangsha 410083China

Forced mixing to a single-phase or supersaturated solid solution(SSS)and its prerequisite microstructure evolution in immiscible systems has been a focus of research for fundamental science and practical *** the formation of SSS by shear deformation could enable a material design beyond conventional equilibrium microstructure in immiscible ***,a highly immiscible Cu-50 at.%Cr binary alloy(mixing enthalpy of∼20 kJ mol^(−1))was employed to investigate the microstructure evolution and localized tendencies of SSS during severe shear *** results demonstrate the dislocation mediated microstructural refinement process in each phase of the binary alloy and the mechanisms associated with localized solute supersaturation as a function of shear *** grain refinement in the softer Cu phase occurs owing to the strain localization driving the preferential dynamic *** grain refinement of the Cr phase,however,is enabled by the progressive evolution of grain lamination,splitting,and fragmentation as a function of shear *** solute supersaturation is found to be strongly dependent on the local environments that affect the dislocation activity,including the level of microstructure refinement,the interfacial orientation relationship,the mechanical incompatibility,and the localized preferential phase *** initio simulations confirm that it is more favorable to oxidize Cr than Cu at incoherent Cu/Cr interfaces,limiting the mass transport on an incoherent *** results unveil the mechanism underpinning the non-equilibrium mass transport in immiscible systems upon severe deformation that can be applied to produce immiscible alloys with superior mechanical properties.

关键词： Tribology Immiscible alloys Nanostructures shear deformation Forced mixing Atom probe

Micro Defects Evolution of Nickel-Based Single Crystal Superalloys during shear deformation:A Molecular Dynamics Study

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Acta Metallurgica Sinica(English Letters) 2023年第12期36卷 2089-2099页

作者： Peng Zhang Ming Chen Qiang Zhu Linfu Zhang Guohua Fan Heyong Qin Qiang Tian National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China School of Materials Science and Engineering Harbin Institute of TechnologyWeihai 264209China Key Laboratory for Light-Weight Materials Nanjing Tech UniversityNanjing 211816China Central Iron&Steel Research Institute Group Beijing 100081China

Nickel-based single crystal superalloys have become the main structural materials of the aero-engines due to excellent high-temperature *** micro defects evolution of nickel-based single crystal superalloys under shear deformation was investigated by molecular dynamics(MD)simulations in the present *** is found that the interfacial dislocations decompose into Shockley dislocations under low shear stress,resulting in the plastic deformation of the Ni *** initial plastic deformation of the Ni3Al phase is caused by Shockley dislocations cutting into the Ni3Al *** following deformation from low temperature to medium temperature is controlled by dislocation slip,but the deformation at high temperature is *** is also found that the microvoid evolution can be divided into void growth and coalescence during shear *** microvoid could prevent dislocation entanglement,accelerate dislocation decomposition,and promote earlier plastic deformation under relatively low temperatures.

关键词： Nickel-based single crystal superalloys Micro defects evolution Molecular dynamics simulation shear deformation

Comparison of contribution of sub-rapid cooling and shear deformation to refinement of Fe-rich phase in hypereutectic Al-Fe alloy during rheo-extrusion

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Journal of Iron and Steel Research International 2020年第11期27卷 1294-1302页

作者： Xiang Wang Ren-guo Guan Yuan-dong Li Ti-jun Chen State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou 730050GansuChina School of Materials Science and Engineering Northeastern UniversityShenyang 110819LiaoningChina

A hypereutectic Al-3Fe(wt.%)alloy was subjected by rheo-extrusion,and the effect of sub-rapid cooling and shear deformation on the refinement of Fe-rich phase was *** results showed that both the primary Fe-rich phase and eutectic Fe-rich phase in the solidified Al-Fe alloy were finer than the platelike Fe-rich phase in the as-cast Al-Fe alloy with the same content of *** solidified Al-Fe alloy was subjected to three stages of shear deformation,and both the primary Fe-rich phase and eutectic Fe-rich phase were fractured and the average length was refined to 400 nm,while Fe-rich phase in the as-cast Al-3Fe(wt.%)alloy was platelike and its average length was 40 *** tensile strength and elongation of the hypereutectic Al-3Fe(wt.%)alloy containing nanosized Fe-rich phase were 162 MPa and 25.78%while those of the as-cast AI-3Fe(wt.%)alloy containing coarse platelike Fe-rich phase were 102 MPa and 16.84%,*** the refineme nt of Fe-rich phase in hypereutectic Al-Fe alloy during rheo-extrusion,the three stages of shear deformation contributed more than sub-rapid cooling.

关键词： Fe-rich phase Hypereutectic Al-Fe alloy Refinement Sub-rapid cooling shear deformation

Closed-form solution for shear lag effects of steel-concrete composite box beams considering shear deformation and slip

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Journal of Central South University 2012年第10期19卷 2976-2982页

作者：周旺保蒋丽忠刘志杰刘小洁 School of Civil Engineering Central South University National Engineering Laboratory for High Speed Railway Construction

Based on the consideration of longitudinal warp caused by shear lag effects on concrete slabs and bottom plates of steel beams,shear deformation of steel beams and interface slip between steel beams and concrete slabs,the governing differential equations and boundary conditions of the steel-concrete composite box beams under lateral loading were derived using energy-variational *** closed-form solutions for stress,deflection and slip of box beams under lateral loading were obtained,and the comparison of the analytical results and the experimental results for steel-concrete composite box beams under concentrated loading or uniform loading verifies the closed-form *** investigation of the parameters of load effects on composite box beams shows that:1) Slip stiffness has considerable impact on mid-span deflection and end slip when it is comparatively small;the mid-span deflection and end slip decrease significantly with the increase of slip stiffness,but when the slip stiffness reaches a certain value,its impact on mid-span deflection and end slip decreases to be negligible.2) The shear deformation has certain influence on mid-span deflection,and the larger the load is,the greater the influence is.3) The impact of shear deformation on end slip can be neglected.4) The strain of bottom plate of steel beam decreases with the increase of slip stiffness,while the shear lag effect becomes more significant.

关键词： steel-concrete composite box beam shear lag effect shear deformation slip closed-form solution

Closed-form solution to thin-walled box girders considering effects of shear deformation and shear lag

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Journal of Central South University 2012年第9期19卷 2650-2655页

作者：周旺保蒋丽忠刘志杰刘小洁 School of Civil Engineering Central South University National Engineering Laboratory for High Speed Railway Construction(Central South University)

Considering three longitudinal displacement functions and uniform axial displacement functions for shear lag effect and uniform axial deformation of thin-walled box girder with varying depths,a simple and efficient method with high precision to analyze the shear lag effect of thin-walled box girders was *** governing differential equations and boundary conditions of the box girder under lateral loading were derived based on the energy-variational method,and closed-form solutions to stress and deflection corresponding to lateral loading were *** and calculations were carried out with respect to a trapezoidal box girder under concentrated loading or uniform loading and a rectangular box girder under concentrated *** analytical results were compared with numerical solutions derived according to the high order finite strip element method and the experimental *** investigation shows that the closed-form solution is in good agreement with the numerical solutions derived according to the high order finite strip method and the experimental results,and has good *** of the shear lag effect,the stress in cross-section centroid is no longer zero,thus it is not reasonable enough to assume that the strain in cross-section centroid is zero without considering uniform axial deformation.

关键词： shear lag effect thin-walled box girder energy-variational method shear deformation closed-form solution

Asymmetry in interface and bending property of Al/Cu/Al bimetallic laminates

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Rare Metals 2014年第5期33卷 556-562页

作者： Xiao-Bing Li Guo-Yin Zu Ping Wang School of Materials and Metallurgy Northeastern University

This work was aimed to study the interfacial microstructures and three-point bending properties of Al/Cu/Al bimetallic laminates produced by the asymmetrical roll bonding and annealing. It is found that the microstructure and bonding strength of the Al/Cu interface are different with those of the Cu/Al interface. The interfacial microstructure of Cu/Al interface is improved due to the large interfacial plastic deformation caused by the different rotation speeds of roll in the asymmetrical roll bonding process. The bonding strength between Al and Cu layer can be enhanced by the moderate atomic diffusion, but is dramatically depressed by the formation of intermetallic compounds in the *** bending strength of bimetallic laminates is enhanced when the Cu/Al interface is loaded in tension because of the improvement of stress transition and damping by the Cu/Al interface during the three-point bending deformation. The bending fracture reveals that the interfacial cracks can be inhibited from the restricted stress concentration in the improved Cu/Al interface.

关键词： Layered structures Bending test Interface shear deformation

Development of through-thickness texture gradient and persistence of shear-type textures during annealing of commercial purity aluminium sheet processed by accumulative roll-bonding

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Journal of Materials Science & Technology 2018年第5期34卷 821-831页

作者： Saiyi Li Liang Yang Nan Qin School of Materials Science and Engineering Central South University Changsha 410083 China Key Laboratory of Nonferrous Metal Materials Science and Engineering of the Ministry of Education Central South University Changsha 410012 China

Ultrafine-grained commercial-purity aluminum（AA1070） sheets produced by four cycles of accumulative roll-bonding（ARB） without lubrication are subjected to annealing treatments in the temperature range from 250℃ to 400℃.Microstructures and microtextures in the surface and center regions of the ARBed and annealed sheets are measured by electron backscatter *** results show that annealing treatments at 325℃ or above lead to a reduction in the microstructure gradient but a significant through-thickness texture gradient different from that in the as-deformed *** center region is featured by the development of a strong cube texture at the expense of rolling *** the surface region,shear-type components are either enhanced or largely retained,showing a high persistency upon *** the grain structures are restored predominantly by continuous recrystallization in the surface region,a mixture of continuous and discontinuous recrystallization is envisaged for the center region.

关键词： Accumulative roll-bonding Texture Annealing Recrystallization shear deformation

A novel hybrid design method of lattice structure based on failure mode

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Science China(Physics,Mechanics & Astronomy) 2022年第9期65卷 79-91页

作者： Chuanlei Li Junfeng Qi Panding Wang Zeang Zhao Zhe Wang Hongshuai Lei Shengyu Duan Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Beijing Spacecrafts Beijing 100094China

Adjusting the mechanical properties of lattice structures is important for many modern application fields. In this paper, a new design method for hybrid multi-layer lattice structures was developed to improve the mechanical properties and energy absorption, by altering and suppressing the formation of the shear band. In these hybrids, all unit cells were divided into two parts:(i) diagonal unit cells and(ii) matrix unit cells. Four categories of unit cells were selected to construct the hybrid multi-layer structures. The compressive moduli, ultimate strengths, and energy absorption properties of the laser powder bed fusion(L-PBF)fabricated structures were assessed by experiments and finite element analysis(FEA). The results revealed the great impact of diagonal unit cells on the mechanical properties of the structures. Stronger diagonal unit cells than matrix unit cells led to hybrid structures with enhanced mechanical properties. Compared with a uniform body-centered cubic(BCC) lattice structure, the relative density of the lattice structure consisting of the weakest BCC matrix unit cells and strongest BFVC diagonal unit cells(coupling of BCC, FCC, and VC) exhibited an increase of 20%. The compressive modulus and ultimate strength of this structure rose by more than 200% and 90%, respectively. Two types of structures with specific properties were generated by hybrid *** first displayed higher modulus, superior strength, and elevated specific energy absorption(SEA) but lower crash load efficiency(CLE). The second illustrated simultaneously higher SEA and elevated CLE. The present results provide a new insight for improving the load-bearing and energy absorption capacities of lattice structures.

关键词： additive manufacturing lattice structure shear deformation hybrid mechanical properties

Variation in Texture and Lankford Value of 1070 Aluminum Sheet Rolled by Cone-shaped Roll

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Journal of Materials Science & Technology 2013年第2期29卷 175-179页

作者： Yasumasa Chino Xinsheng Huang Kazutaka Suzuki Mamoru Mabuchi Materials Research Institute for Sustainable Development National Institute of Advanced Industrial Science and Technology 2266-98 AnagahoraShimo-shidami Moriyama-ku Nagoya 463-8560 Japan Department of Energy Science and Technology Graduate School of Energy Science Kyoto University Yoshida-honmachi Sakyo-ku Kyoto 606-8501 Japan

A rolling with cone-shaped roll, the diameter of which continuously varies along the axial direction, has been proposed as a new shear rolling for controlling the texture of an aluminum alloy sheet. In this study, variations in the texture and Lankford value of a 1070 aluminum sheet rolled by the cone-shaped roll were investigated. Rolling with the cone-shaped roll was found to impose intense shear strain at the edges of the specimen, specifically near the surface. The shear directions in the left and right portions of the specimen were opposite to each other. The surface and middle layer of the specimen rolled by the cone-shaped roll and the reference specimen were characterized by a shear texture and typical recrystallization texture components, respectively. Notably, the specimen rolled by the cone-shaped roll exhibited smaller texture intensity than the reference specimen, especially at the surface, and the shear texture-components were observed at relatively deeper positions. As a result of Lankford value measurements, the specimen rolled with the cone-shape roll exhibited a smaller planar anisotropy than the reference specimen and an average Lankford value close to unity, which are likely due to the texture modifications introduced during rolling with the cone-shaped roll.

关键词： Aluminum Mechanical properties Texture Rolling shear deformation