检索结果-南通市图书馆

Sample size effect on the dynamic torsional behaviour of the 2A12 aluminium alloy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Theoretical & Applied Mechanics Letters 2017年第6期7卷 317-324页

作者： J.H.Chen W.F.Xu r.z.xie F.J.zhang W.J.Hu X.C.Huang G.Chen Institute of Systems Engineering China Academy of Engineering PhysicsMianyangSichuan 621999China

In order to investigate the effect of sample size on the dynamic torsional behaviour of the 2A12 aluminium alloy. In this paper, torsional split Hopkinson bar tests are conducted on this alloy with different sample dimensions. It is found that with the decreasing gauge length and thickness, the tested yield strength increases. However, the sample innerlouter diameter has little effect on the dynamic torsional behaviour. Based on the finite element method, the stress states in the alloy with different sample sizes are analysed. Due to the effect of stress concentration zone （SCz）, the shorter sample has a higher yield stress. Furthermore, the stress distributes more uniformly in the thinner sample, which leads to the higher tested yield stress. According to the experimental and simulation analysis, some suggestions on choosing the sample size are given as well.

关键词： Torsional split Hopkinson bar Dynamic torsion Sample size effect Finite element analysis Stress distribution

3D Printing of Tough Hydrogel Scaffolds with Functional Surface Structures for Tissue regeneration

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第2期17卷 18-45页

作者： Ke Yao Gaoying Hong Ximin Yuan Weicheng Kong Pengcheng Xia Yuanrong Li Yuewei Chen Nian Liu Jing He Jue Shi zihe Hu Yanyan zhou zhijian xie Yong He State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China Liangzhu Laboratory Zhejiang UniversityHangzhou 310027People’s Republic of China Key Laboratory of 3D Printing Process and Equipment of zhejiang Province College of Mechanical EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China Stomatology Hospital School of StomatologyZhejiang University School of MedicineHangzhou 310027People’s Republic of China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001People’s Republic of China Institute of Digital Medicine Nanjing First HospitalNanjing Medical UniversityNanjing 210006People’s Republic of China

Hydrogel scaffolds have numerous potential applications in the tissue engineering ***,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical *** by Chinese ramen,we propose a universal fabricating method(printing-P,training-T,cross-linking-C,PTC&PCT)for tough hydrogel scaffolds to fill this ***,3D printing fabricates a hydrogel scaffold with desired structures(P).Then,the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance(T).Finally,the training results are fixed by photo-cross-linking processing(C).The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa(622-fold untreated)and have excellent ***,this scaffold possesses functional surface structures from nanometer to micron to millimeter,which can efficiently induce directional cell ***,this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt,and many hydrogels,such as gelatin and silk,could be improved with PTC or PCT *** experiments show that this scaffold can effectively promote the new generation of muscle fibers,blood vessels,and nerves within 4 weeks,prompting the rapid regeneration of large-volume muscle loss injuries.

关键词： 3D printing Tough hydrogel scaffold Functional surface structure Tissue regeneration Biomaterials

Microstructure and Mechanical Properties of X80 Pipeline Steel Joints by Friction Stir Welding Under Various Cooling Conditions

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2020年第1期33卷 88-102页

作者： G.M.xie r.H.Duan P.Xue z.Y.Ma H.L.Liu z.A.Luo State Key Laboratory of rolling and Automation Northeastern UniversityShenyang 110819China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

X80 pipeline steel plates were friction stir welded(FSW)under air,water,liquid CO2+water,and liquid CO2 cooling conditions,producing defect-free *** microstructural evolution and mechanical properties of these FSW joints were *** granular bainite was observed in the nugget zone(Nz)under air cooling,and lath bainite and lath martensite increased signifi cantly as the cooling medium temperature *** particular,under the liquid CO2 cooling condition,a dual phase structure of lath martensite and fi ne ferrite appeared in the *** to the case under air cooling,a strong shear texture was identifi ed in the Nzs under other rapid cooling conditions,because the partial deformation at elevated temperature was retained through higher cooling *** liquid CO2 cooling,the highest transverse tensile strength and elongation of the joint reached 92%and 82%of those of the basal metal(BM),respectively,due to the weak tempering softening.A maximum impact energy of up to 93%of that of the BM was obtained in the Nz under liquid CO2 cooling,which was attributed to the operation of the dual phase of lath martensite and fi ne ferrite.

关键词： Friction stir welding Pipeline steel Microstructure Mechanical properties Cooling

Deciphering deformation mechanisms of hierarchical dual-phase CrCoNi coatings

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第4期39卷 7-13页

作者： S.J.Tsianikas Y.Chen z.xie School of Mechanical Engineering The University of AdelaideAdelaideSA5005Australia Centre for Advanced Thin Film Materials and Device Faculty of Materials and EnergySouthwest UniversityChongqing400715China School of Engineering Edith Cowan UniversityWA6027Australia

Hierarchical Cr Co Ni medium entropy alloy(MEA)thin films with a dual-phase face-centred cubic(FCC)and hexagonal closed-packed(HCP)nanostructure were prepared on M2 steel substrates by closed field unbalanced magnetron *** tests show an ultra-high hardness of 9.5 GPa,attributable to large amounts of innate planar defects(i.e.,growth twins and stacking faults)impeding dislocation motion in the coatings.A deep analysis of undeformed and post-mortem samples reveals grain refinement as the dominant deformation mechanism in FCC dominated regions,while phase transformation and shear banding played major roles in regions occupied by HCP *** grain refinement was facilitated by twin/matrix lamellae,with dislocations piling up and arranging into interconnecting grain *** shear banding was accelerated by innate planar defects in the HCP phase due to a lack of slip *** particular interest is the observation of HCP→FCC phase transformation,which was catalysed by deformation-induced grain reorientation with innate stacking faults acting as embryos to grow the FCC *** results of this work suggest that multiple deformation pathways could be activated in Cr Co Ni coatings with assistance of growth defects,thereby imparting these technically important coatings appreciable ductility.

关键词： Medium entropy alloys Sputter deposition Grain refinement Shear banding Phase transformation

Microstructural refinement mechanism and its effect on toughness in the nugget zone of high-strength pipeline steel by friction stir welding

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第34期93卷 221-231页

作者： r.H.Duan G.M.xie P.Xue z.Y.Ma z.A.Luo C.Wang r.D.K.Misra State Key Laboratory of rolling and Automation Northeastern UniversityNo.3 Wenhua RoadShenyang 110819China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of Metallurgy Northeastern UniversityNo.3 Wenhua RoadShenyang 110819China Department of Metallurgical Materialsand Biomedical EngineeringUniversity of Texas at El PasoTX 79968USA

High-strength pipeline steel was subjected to friction stir welding(FSW)at rotation rates of 400-700 rpm,and the grain refinement mechanism of the nugget zone(Nz)was *** thermomechanical process during FSW in the Nz was simulated by multi-pass thermal compression,thereby achieving the austenitic non-recrystallization temperature(T_(nr)).The austenitic non-recrystallization in the Nz at the lowest rotation rate of 400 rpm caused a significant grain ***,the reduced rotation rate also resulted in the formation of a high ratio of island-like martensite-austenite(M-A)*** toughness of the Nzs was enhanced as the rotation rate decreased,which is attributed to the fine effective grains and homogeneously distributed fine M-A constituents dramatically inhibiting crack initiation and propagation.

关键词： Pipeline steel Friction stir welding Grain refinement M-A constituent Toughness

Printing perovskite and graphene parallel structure-based optical-mechanical sensors for human-machine interaction

在线全文

学校读者我要写书评

暂无评论

Science China Technological Sciences 2025年

作者： Sisi CHEN Jiemin zHANG Nan CHENG Wenbo LI Jing LIU Hongfei xie Jie zHANG Yueying CHENG Xiaotong zHAO Meng SU Yanlin SONG Key Laboratory of Green Printing CAS Research/Education Center for Excellence in Molecular Sciences Institute of ChemistryChinese Academy of Sciences (ICCAS) University of Chinese Academy of Sciences Weiyang College Tsinghua University Department of Cardiovascular Surgery First Medical Center PLA General Hospital AECC Beijing Institute of Aeronautical Materials Beijing Institute of Graphene Technology Beijing Engineering research Centre of Graphene Application School of Integrated Circuit & Beijing National research Center for Information Science and Technology (BNrist) Tsinghua University

Surgical robots are designed to provide enhanced precision and dexterity compared to manual surgical procedures,which mainly rely on multimodal sensing technologies for the surgeon to seamlessly operate the robotic arms and *** with single-mode sensors, optical and mechanical bi-modal sensors provide improved precision, enhanced safety,and robustness of human-machine interaction systems. Here, the template-guided and pneumatic printing technologies are combined to construct perovskite and graphene parallel structures with both optical and mechanical sensing capabilities. The printed uniformly crystallized perovskite microstructure exhibits fast and sensitive photoelectric response characteristics,enabling shadow recognition functionality. The combination of graphene and elastic rubber endows the great printability to prepare parallel structures near the perovskite arrays for force sensing capabilities. Thus, the printed perovskite and graphene structures possess non-contact optical sensing capabilities to detect hand position by recognizing shadows between the hand and the sensor, as well as contact mechanical sensing capabilities to detect touch force applied by the hand. It provides a synergistic platform for real-time and multidimensional feedback to improve human-machine interaction.

关键词：

Mechanistic investigation on Ce addition in tuning recrystallization behavior and mechanical property of Mg alloy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第1期132卷 1-17页

作者： J.r.Li D.S.xie z.r.zeng B.Song H.B.xie r.S.Pei H.C.Pan Y.P.ren G.W.Qin Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) College of Materials Science and EngineeringNortheastern UniversityShenyang110819China College of Engineering and Computer Science Australian National UniversityACT 2601Australia School of Materials and Energy Southwest UniversityChongqing 400715China Institute for Physical Metallurgy and Materials Physics RWTH Aachen UniversityAachen 52062Germany

Constructing bimodal grain structure is a promising approach to achieve the high strength-ductility syn-ergy in Mg *** of bimodal grain is closely related to the dynamic and/or static recrystal-lization process,which has not been fully understood in the typical Mg-rE based *** this work,it is claimed for the first time that the minor Ce addition(∼0.3 wt%)into Mg matrix significantly pro-motes the pyramidaland non-basaldislocations at the early stage of extrusion,which con-sequently enhances the formation of sub-grain boundaries via the movement and recovery of pyramidal II-type*** this stage,fine sub-grain lamellae are widely observed predominantly due to the low migration rate of sub-grain boundary caused by the limited mobility of*** the later stage,the sub-grains continuously transform into dynamic recrystallized(DrXed)grains that have10¯10Taylor axis and also strong fiber texture,indicating substantial activation of pyramidal II-type*** low mobility ofdislocations,accompanied with the solute drag from grain boundary(GB)segregation and pinning from nano-phases,cause a sluggish DrX process and thus a bimodal microstructure with ultra-fined DrXed grains,∼0.51μ*** resultant texture hardening and grain refinement hardening effects,originated from bimodal microstructure,result in a yield strength of∼352 MPa,which is exceptional in Mg-Ce dilute *** work clarifies the critical role of Ce addition in tuning recrystallization behavior and mechanical property of magnesium,and can also shed light on designing the other high-performance Mg alloys.

关键词： Mg alloys recrystallization behavior Mechanical property Pyramidal dislocation Thermal stability

Anisotropic time-dependent behaviors of shale under direct shearing and associated empirical creep models

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1262-1279页

作者： Yachen xie Michael z.Hou Hejuan Liu Cunbao Li Shenzhen Key Laboratory of Deep Engineering Sciences and Green Energy Shenzhen UniversityShenzhen518060China Institute of Subsurface Energy Systems Clausthal University of TechnologyClausthal-Zellerfeld38678Germany State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China

Understanding the anisotropic creep behaviors of shale under direct shearing is a challenging *** this context,we conducted shear-creep and steady-creep tests on shale with five bedding orientations (i.e.0°,30°,45°,60°,and 90°),under multiple levels of direct shearing for the first *** results show that the anisotropic creep of shale exhibits a significant stress-dependent *** a low shear stress,the creep compliance of shale increases linearly with the logarithm of time at all bedding orientations,and the increase depends on the bedding orientation and creep *** high shear stress conditions,the creep compliance of shale is minimal when the bedding orientation is 0°,and the steady-creep rate of shale increases significantly with increasing bedding orientations of 30°,45°,60°,and 90°.The stress-strain values corresponding to the inception of the accelerated creep stage show an increasing and then decreasing trend with the bedding orientation.A semilogarithmic model that could reflect the stress dependence of the steady-creep rate while considering the hardening and damage process is *** model minimizes the deviation of the calculated steady-state creep rate from the observed value and reveals the behavior of the bedding orientation's influence on the steady-creep *** applicability of the five classical empirical creep models is quantitatively *** shows that the logarithmic model can well explain the experimental creep strain and creep rate,and it can accurately predict long-term shear creep *** on an improved logarithmic model,the variations in creep parameters with shear stress and bedding orientations are *** abovementioned findings,a mathematical method for constructing an anisotropic shear creep model of shale is proposed,which can characterize the nonlinear dependence of the anisotropic shear creep behavior of shale on the bedding orientation.

关键词： rock anisotropy Direct shear creep Creep compliance Steady-creep rate Empirical model Creep constitutive model

Diffusion behavior of Cr in gradient nanolaminated surface layer on an interstitial-free steel

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第3期35卷 460-464页

作者： S.L.xie z.B.Wang K.Lu Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences School of Materials Science and Engineering University of Science and Technology of China

Nanolaminated structures composed of low-angle grain boundaries(LAGBs) possess high thermal stability. In this paper, a gradient nanolaminated(GNL) surface layer with smooth finish was fabricated on an interstitial-free steel by means of surface mechanical rolling treatment. Microstructural observations demonstrated that the average lamellar thickness is about 80 nm in the topmost surface layer and increases with increasing depth. High thermal stability was confirmed in the GNL surface layer after annealing at 500℃. Diffusion measurements showed that effective diffusivity of Cr in GNL layer is 4–6 orders of magnitude higher than lattice diffusivity within the temperature range from 400 to 500℃. This might be attributed to numerous LAGBs or dislocation structures with a higher energy state in the GNL surface layer. This work demonstrates the possibility to advanced chromizing(or other surface alloying)processes of steels with formation of GNL surface layer, so that a thicker alloyed surface layer with a stable nanostructure is achieved.

关键词： Gradient nanolaminated structure Interstitial-free steel Diffusion Low-angle grain boundary Surface mechanical rolling treatment