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Journal of Materials Science & Technology 2020年第10期42卷 108-116页

作者： h.Chen A.Rushworth Department of Mechanical Materials and Manufacturing EngineeringFaculty of Science and EngineeringUniversity of Nottingham Ningbo ChinaNingbo 315100China

This paper details an investigation of the effects of oxide stringers on theβ-phase depletion behaviour in thermally sprayed CoNiCrAlY coatings.Vacuum Plasma Sprayed(VPS)Co NiCrAlY coatings,which are free of oxide stringers,are used as the reference materials in comparison with high-Velocity Oxy-Fuel(hVOF)sprayed CoNiCrAlY coatings during isothermal oxidation at 1100℃.An outer layer of spinel oxides and an inner layer of alumina are formed in the as-sprayed coatings,while only a single alumina scale is found in the heat-treated coatings.Lessβ-phase depletion occurred in the hVOF coatings than in the VPS coatings.It was found that theβphases tend to coalesce at the oxide stringers in the hVOF coatings,which is likely due to the internal oxide particles and stringers acting as short diffusion barriers to tie up theβphase and inhibit theβ-phase depletion.

关键词： MCrAlY β-Phase depletion Oxidation Diffusion

Alloy solidification: Assessment and improvement of an easy-to-apply model

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Journal of Materials Science & Technology 2022年第35期130卷 1-11页

作者： h.Liu Y.Liu S.L.Lu Y.Zhang h.Chen Y.chen M.Qian School of Materials Science and Engineering Southwest Jiaotong UniversityChengdu 610031China Centre for Additive Manufacturing School of EngineeringRMIT UniversityMelbourneVIC 3000Australia School of Materials Science and Engineering Sichuan UniversityChengdu 610065China

It has been a central task of solidification research to predict solute microsegregation. Apart from the Lever rule and the Scheil-Gulliver equation, which concern two extreme cases, a long list of microsegregation models has been proposed. however, the use of these models often requires essential experimental input information, e.g., the secondary dendrite arm spacing(λ), cooling rate( ˙T) or actual solidification range(△T). This requirement disables these models for alloy solidification with no measured values for λ,˙T and △T. Furthermore, not all of these required experimental data are easily obtainable. It is therefore highly desirable to have an easy-to-apply predictive model that is independent of experimental input,akin to the Lever rule or Scheil-Gulliver model. Gong, chen, and co-workers have recently proposed such a model, referred to as the Gong-chen model, by averaging the solid fractions(f_(s)) of the Lever rule and Scheil-Gulliver model as the actual solid fraction. We provide a systematic assessment of this model versus established solidification microsegregation models and address a latent deficiency of the model, i.e.,it allows the Lever rule solid fraction fsto be greater than one(f_(s)> 1). It is shown that the Gong-chen model can serve as a generic model for alloy solidification until fsreaches about 0.9, beyond which(f_(s)> 0.9) its applicability is dictated by both the equilibrium solute partition coefcient(k) and the solute diffusion coefcient in the solid(Ds), which has been tabulated in detail.

关键词： Solidification Microsegregation Solute Back diffusion Eutectic formation

Review on hydrogen Embrittlement of Press-hardened Steels for Automotive Applications

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Acta Metallurgica Sinica(English Letters) 2023年第7期36卷 1123-1143页

作者： Z.Wang Q.Lu Z.h.Cao h.Chen M.X.huang J.F.Wang General Motors China Science Lab Shanghai201206China Department of Mechanical Engineering The University of Hong KongPokfulam RoadHong Kong999077China Key Laboratory for Advanced Materials of Ministry of Education School of Materials Science and EngineeringTsinghua UniversityBeijing100084China

Press-hardened steel(PhS)with an ultimate tensile strength(UTS)of 1500 MPa has been widely used in automotive body-in-white in the last two decades,due to its ultra-high strength and excellent formability that is achieved by hot stamping process.however,the application of PhS with UTS exceeding 1500 MPa in automotive industry could be deferred due to the increased risk of hydrogen embrittlement.To reduce this kind of risk,recent research efforts have been focused on various ways to optimize the microstructure of PhS.The present review intends to summarize these efforts,to highlight present solutions to address hydrogen embrittlement,and to shed light on directions for future improvement.The influence of microstructure on the hydrogen embrittlement of PhS has been discussed in terms of both the steel substrate and the surface condition.The substrate part covers the influence of martensite,carbides,inclusions,and retained austenite,while the surface part covers decarburization and oxidation,pre-coating,and trimming.

关键词： hot stamping Press-hardened steels Coating-free hydrogen embrittlement Fracture Al-Si coating

how sugar instigates macrophages to be evils in tumor

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Cellular & Molecular Immunology 2022年第12期19卷 1325-1327页

作者： houjun Xia Youhai h.Chen Center for Cancer Immunology Institute of Biomedicine and BiotechnologyShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenChina

In a recent issue of the journal Cancer Cell,Shi et al.reported that glucose metabolism remodels pro-tumoral functions of tumor-associated macrophages(TAMs)to support cancer metastasis and chemoresistance.Mechanistically,the consumption of glucose fuels hexosamine biosynthetic pathway(hBP)and enhances O-GlcNAcylation of Cathepsin B in macrophages,which upon secretion disrupts the tumor microenvironment(TME)[1].

关键词： metabolism tumor

Enhancing strength and ductility of AlSi10Mg fabricated by selective laser melting by TiB_(2)nanoparticles

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Journal of Materials Science & Technology 2022年第14期109卷 254-266页

作者： Y.K.Xiao h.Chen Z.Y.Bian T.T.Sun h.Ding Q.Yang Y.Wu Q.Lian Z.chen h.W.Wang State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China School of Materials Science&Engineering Shanghai Jiao Tong UniversityShanghai 200240China

In the metallic components fabricated by the emerging selective laser melting(SLM)technology,most strategies used for strengthening the materials sacrifice the ductility,leading to the so-called strengthductility trade-off.In the present study,we report that the strength and ductility of materials can be enhanced simultaneously by introducing nanoparticles,which can break the trade-off of the metallic materials.In the case of in-situ nano-TiB_(2)decorated AlSi10Mg composites,the introduced nanoparticles lead to columnar-to-equiaxed transition,grain refinement and texture elimination.With increasing content of nanoparticles,the strength increases continually.Significantly,the ductility first increases and then decreases.Our results show that the ductility is controlled by the competition between the crack-induced catastrophic fracture and ductile fracture associated with dislocation activities.The first increase of ductility is mainly attributed to the suppression of crack-induced catastrophic fracture when TiB_(2)nanoparticles present.With the further increase of TiB_(2)nanoparticles,the subsequent decrease of ductility is mainly controlled by dislocation activities.Thus,the materials will exhibit the optimum strength and ductility combination in a certain range of TiB_(2)nanoparticles.This study clarifies the physical mechanism controlling ductility for nano-TiB_(2)decorated Al Si10Mg composites,which provides the insights for the design of structural materials.

关键词： Selective laser melting Aluminium matrix composites Ductility Mechanical behavior Dislocations Cracks

A portable device for studying the effects of fluid flow on degradation properties of biomaterials inside cell incubators

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Regenerative Biomaterials 2019年第1期6卷 39-48页

作者： Wensen Jiang Jiajia Lin Alex h.Chen Jianwei Pan huinan Liu Department of Bioengineering Materials Science and Engineering ProgramStem Cell Center Department of Mechanical Engineering University of CaliforniaRiversideRiversideCA 92521USA Department of Bioengineering University of CaliforniaRiversideRiversideCA 92521USA Department of Neurosurgery The First Affiliated Hospital of Zhejiang UniversityHangzhou 310003China

A portable device was designed and constructed for studying the properties of biomaterials in physiologically relevant fluids under controllable flow conditions that closely simulate fluid flow inside the body.The device can fit entirely inside a cell incubator;and,thus,it can be used directly under standard cell culture conditions.An impedance-driven pump was built in the sterile flow loop to control the flow rates of fluids,which made the device small and portable for easy deployment in the incubator.To demonstrate the device functions,magnesium(Mg)as a representative biodegradable material was tested in the flow device for immersion degradation under flow versus static conditions,while the flow module was placed inside a standard cell incubator.The flow rate was controlled at 0.1760.06 ml/s for this study;and,the flow rate is adjustable through the controller module outside of incubators for simulating the flow rates in the ranges of blood flow in human artery(0.050.43 ml/s)and vein(0.020.08 ml/s).Degradation of Mg under flow versus static conditions was characterized by measuring the changes of sample mass and thickness,and Mg2t ion concentrations in the immersion media.Surface chemistry and morphology of Mg after immersion under flow versus static conditions were compared.The portable impedance-driven flow device is easy to fit inside an incubator and much smaller than a peristaltic pump,providing a valuable solution for studying biomaterials and implants(e.***.vascular or ureteral stents)in body fluids under flow versus static conditions with or without cells.

关键词： portable flow device impedance-driven pump biomaterials body fluids magnesium(Mg)degradation

Microbiologically influenced corrosion of cable bolts in underground coal mines:The effect of Acidithiobacillus ferrooxidans

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International Journal of Mining Science and Technology 2021年第3期31卷 357-363页

作者： h.Chen O.Kimyon h.Lamei Ramandi M.Manefield A.h.Kaksonen C.Morris A.Crosky S.Saydam School of Materials Science and Engineering UNSW SydneyNSW 2052Australia School of Chemical Engineering UNSW SydneyNSW 2052Australia School of Minerals and Energy Resources Engineering UNSW SydneyNSW 2052Australia CSIRO Land and Water FloreatWA 6014Australia

Reports on corrosion failure of cable bolts,used in mining and civil industries,have been increasing in the past two decades.The previous studies found that pitting corrosion on the surface of a cable bolt can initiate premature failure of the bolt.In this study,the role of Acidithiobacillus ferrooxidans(A.ferrooxidans)bacterium in the occurrence of pitting corrosion in cable bolts was studied.Stressed coupons,made from the wires of cable bolts,were immersed in testing bottles containing groundwater collected from an underground coal mine and a mixture of A.ferrooxidans and geomaterials.It was observed that A.ferrooxidans caused pitting corrosion on the surface of cable bolts in the near-neutral environment.The presence of geomaterials slightly affected the p h of the environment;however,it did not have any significant influence on the corrosion activity of A.ferrooxidans.This study suggests that the common bacterium A.ferrooxidans found in many underground environments can be a threat to cable bolts'integrity by creating initiation points for other catastrophic failures such as stress corrosion cracking.

关键词： Cable bolt failure Microbiologically influenced corrosion Acidithiobacillus ferrooxidans

Laser additive manufacturing for infrastructure repair:A case study of a deteriorated steel bridge beam

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Journal of Materials Science & Technology 2023年第23期154卷 149-158页

作者： Shengbiao Zhang Peijun hou Jiyun Kang Tianyi Li Shahryar Mooraj Yang Ren Catherine h.Chen A.John hart Simos Gerasimidis Wen chen Department of Mechanical and Industrial Engineering University of Massachusetts Amherst MA 01003 USA Department of Civil and Environmental Engineering University of Massachusetts Amherst MA 01003 SA Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA X-ray Science Division Argonne National Laboratory Lemont IL 60439 USA Massachusetts Department of Transportation Boston MA 02116 USA Department of Mechanical Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA Department of Physics City University of Hong Kong Kowloon Hong Kong China

As our transportation infrastructure ages,its deterioration is becoming a growing concern.Rapid and effective methods for repair can reduce the need for time-and cost-intensive replacement of structures such as roadway bridges.In this work,laser-based additive manufacturing(AM)was developed for the repair of damaged beams in steel bridges.A corroded structural beam of low-carbon A36 steel was selected for this case study and 316L stainless steel was used for repair due to its excellent mechanical properties and corrosion resistance.Simulated repair experiments were performed on specimens extracted from the beam,and prepared with various groove shapes(Rectangular,Trapezoidal,and U-shaped).More in-depth parametric and microstructural studies were carried out with a series of U-shaped specimens repaired with the linear laser input energy varied from 19.5 to 30.0 J mm–1.The tensile properties of the repaired specimens and interface structures were also investigated in detail.It was found that the repaired specimens had a slightly higher tensile strength despite a reduction in tensile elongation compared to the A36 steel base metal.The influence of interfacial microstructure and heterogeneity on the mechanical properties of the repaired specimens was discussed.Our work suggests the promising potential to employ AM for structural repair and provides fundamental insights into processing-structure-property relationships in laser AM-repaired materials.

关键词： Additive manufacturing Structural repair Mechanical properties Transportation infrastructure Dissimilar joint

Inside-Out 3D Reversible Ion-Triggered Shape-Morphing hydrogels

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Research 2019年第1期2019卷 1237-1248页

作者： X.Du h.Cui Q.Zhao J.Wang h.Chen Y.Wang Institute of Biomedical&health Engineering Shenzhen Institutes of Advanced Technology(SIAT)Chinese Academy of Sciences(CAS)Shenzhen518035China

Shape morphing is a critical aptitude for the survival of organisms and is determined by anisotropic tissue composition and directional orientation of micro-and nanostructures within cell walls,resulting in diferent swelling behaviors.Recent eforts have been dedicated to mimicking the behaviors that nature has perfected over billions of years.We present a robust strategy for preparing 3D periodically patterned single-component sodium alginate hydrogel sheets cross-linked with Ca^(2+)ions,which can reversibly deform and be retained into various desirable inside-out shapes as triggered by biocompatible ions(Na^(+)/Ca^(2+)).By changing the orientations of the patterned microchannels or triggering with Na^(+)/Ca^(2+)ions,various 3D twisting,tubular,and plantinspired architectures can be facilely programmed.Not only can the transformation recover their initial shapes reversibly,but also it can keep the designated shapes without continuous stimuli.Tese inside-out 3D reversible ion-triggered hydrogel transformations shall inspire more attractive applications in tissue engineering,biomedical devices,and sof robotics felds.

关键词： swelling preparing attractive

Modeling and Simulation of Space Target Optical Detection System

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Modeling and Simulation of Space Target Optical Detection Sy...