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Microstructure Evolution and Mechanical Properties of Friction Stir Welded Al-Cu-Li Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 855-871页

作者： Peng Chen Wenhao Chen Jiaxin Chen Zhiyu Chen Yang Tang Ge Liu Bensheng Huang Zhiqing Zhang School of New Energy and Materials Southwest Petroleum UniversityChengdu 610500China Sichuan Provincial Engineering research center of advanced Materials Manufacturing technology for Shale Gas high-Efficient Exploitation Southwest Petroleum UniversityChengdu 610500China College of Materials Science and Engineering Chongqing UniversityChongqing 400045China School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China School of Robot Engineering Yangtze Normal UniversityChongqing 408100China

The investigation concentrates on friction stir welded(FSW)Al-Cu-Li alloy concerning its local microstructural evolution and mechanical *** grain features were characterized by electron back scattered diffraction(EBSD)technology,while precipitate characterization was conducted by using transmission electron microscopy(TEM)aligned along[011]Al and[001]Al zone *** mechanical properties are evaluated through micro-hardness and tensile *** can be found that nugget zones exhibit finely equiaxed grains evolved through complete dynamic recrystallization(DRX),primarily occurring in continuous dynamic recrystallization(CDRX)and discontinuous dynamic recrystallization(DDRX).In the thermal-mechanically affected zone(TMAZ),numerous sub-structured grains,exhibiting an elongated morphology,were created due to partial DRX,signifying the dominance of CDRX,DDRX,and geometric dynamic recrystallization(GDRX)in this region.T_(1)completely dissolves in the nugget zone(NZ)leading to the formation of Guinier-Preston zones and increase ofδ′,β′and S′.Conversely,T_(1)partially solubilizes in TMAZ,the lowest hardness zone(LHZ)and heat affected zone(HAZ),and the residual T_(1)undergoes marked coarsening,revealing various T_(1)*** solubilization and coarsening of T_(1)are primary contributors to the degradation of hardness and strength.θ′primarily dissolves and coarsens in NZ and TMAZ,whilst this precipitate largely coarsens in HAZ and LHZ.σ,TB,grain boundary phases(GBPs)and precipitate-free zone(PFZ)are newly generated during FSW.σexists in the TMAZ,LHZ and HAZ,whereas TB nucleates in *** and PFZ mostly develop in LHZ and HAZ,which can cause strain localization during tensile deformation,potentially leading to LHZ joint fracture.

关键词： Al-Cu-Li alloy Friction stir welding Microstructure evolution Mechanical properties

Nontrivial homoclinic orbits for second-order singular and periodic Hamiltonian systems

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Chinese Science Bulletin 1999年第2期44卷 123-129页

作者： LI Chengyue , FAN Tianyou TONG Mingshengresearch center of Materials Science, Beijing Institute of technology, Beijing 100081, China Department of Mathematics, Central University for Nationalities, Beijing 100081, China Computer center, Beijing Institute of technology, Beijing 100081, China research center of Materials Science Beijing Institute of Technology Beijing China Department of Mathematics Central University for Nationalities Beijing China Computer center Beijing Institute of Technology Beijing China

The existence of nontrivial homoclinic orbits of periodic Hamiltonian systems: is proved, where q=（q1,q2,’',qn）, n>2; V（t, q）:R1×Rn\{e}→R1 is a potential With a singularity, i.e. -V（t, q）→+∞, as q→e. The m... 详细信息

关键词： Hamiltonian systems strong force condition homoclinic orbit.

Magneto-enhanced electro-thermal conversion performance

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Science China Materials 2021年第11期64卷 2835-2845页

作者： Shifang Ma Cuncheng Li Wenjun Cui Xiahan Sang Ping Wei Wanting Zhu Xiaolei Nie Fu-Hua Sun Wenyu Zhao Qingjie Zhang State Key Laboratory of advanced technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Foshan Xianhu Laboratory of the advanced Energy Science and technology Guangdong Laboratory Foshan 528000China Nanostructure research center Wuhan University of TechnologyWuhan 430070China

Synergistically regulating carrier and phonon transport on the nanoscale is extremely difficult for all thermoelectric(TE)materials without cage *** BaFe_(12)O_(19)/Bi_(2)Te_(2.5)Se_(0.5)thermoelectromagnetic nanocomposites are designed and synthesized as a benchmarking example to simultaneously tailor the transport properties on the nanoscale.A magneto-trapped carrier effect induced by BaFe_(12)O_(19)hard-magnetic nanoparticles(NPs)is discovered,which can lower the carrier concentration of n-type Bi_(2)Te_(2.5)Se_(0.5)matrix by 16%,and increase the Seebeck coefficient by 16%.Meanwhile,BaFe_(12)O_(19)NPs provide phonon scattering centers and reduce the thermal conductivity by 12%.As a result,the ZT value of the nanocomposites is enhanced by more than 25%in the range of 300-450 K,and the cooling temperature difference increases by 65%near room *** work greatly broadens the commercial application potential of ntype Bi_(2)Te_(2.5)Se_(0.5),and demonstrates magneto-trapped carrier effect as a universal strategy to enhance the electro-thermal conversion performance of TE materials with high carrier concentration.

关键词： thermoelectromagnetic nanocomposite thermoelectric material magnetic nanoparticles magneto-trapped carrier effect electro-thermal conversion performance

Mechanism of magnetic field-modulated luminescence from lanthanide ions in inorganic crystal:a review

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Rare Metals 2020年第10期39卷 1113-1126页

作者： Shan-Ling Zuo Ping Chen Cao-Feng Pan Guangxi Key Laboratory for Relativistic Astrophysics Center On Nanoenergy ResearchSchool of Physical Science and TechnologyGuangxi UniversityNanning 530004China Beijing Institute of Nanoenergy and Nanosystems National Center for Nanoscience and TechnologyChinese Academy of SciencesBeijing 100083China

The luminescence from lanthanide ions has potential applications in light emitting diodes,biomedical,solar cells,sensors,display,***,the luminescence is suffered from the various problems,such as low luminescence efficiency and inharmonious wavelength for energy *** field is an efficient method to modulate the wavelength and intensity of luminescence from lanthanide *** field redistributes the populated electrons in the excited states to tune the wavelength of lanthanide ions by Zeeman effect,mixing effect,and quantum confinement *** field enhances or suppresses the luminescence intensity by the administration of cross-relaxation,energy transfer,and Boltzmann *** this review,we first introduce the various phenomena and mechanisms of magnetic field modulated downshift luminescence from lanthanide ions,including Zeeman effect,cross-relaxation,crystal structure,absorption,quantum confinement effect,and magneticoptical ***,we explain the regulation of upconversion luminescence by magnetic field,containing energy transfer and mixing ***,different options regarding how to understand the mechanism of magnetic field-modulated luminescence from lanthanide ions in the future are outlined.

关键词： Magnetic field Lanthanide ions Luminescence Microscopic mechanism

Protective electrode/electrolyte interphases for high energy lithium-ion batteries with p-toluenesulfonyl fluoride electrolyte additive

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Journal of Energy Chemistry 2021年第1期30卷 361-371,I0012页

作者： Yanxia Che Xiuyi Lin Lidan Xing Xiongcong Guan Rude Guo Guangyuan Lan Qinfeng Zheng Wenguang Zhang Weishan Li School of Chemistry South China Normal UniversityGuangzhou 510006GuangdongChina National and Local Joint Engineering research center of MPTES in high Energy and Safety LIBs Engineering Research Center of MTEES(Ministry of Education)and Key Lab.of ETESPG(GHEI)South China Normal UniversityGuangzhou 510006GuangdongChina

high energy density lithium-ion batteries using Ni-rich cathode(such as LiNi0.6Co0.2Mn0.2O2) suffer from severe capacity decay.P-toluenesulfonyl fluoride(pTSF) has been investigated as a novel film-forming electrolyte additive to enhance the cycling performances of graphite/LiNi0.6Co0.2Mn0.2O2 pouch *** comparison with the baseline electrolyte,a small dose of pTSF can significantly improve the cyclic stability of the *** calculations together with experimental results indicate that pTSF would be oxidized and reduced to construct protective interphase film on the surfaces of LiNi0.6Co0.2Mn0.2O2 cathode and graphite anode,*** S-containing surface films derived from pTSF effectively mitigate the decomposition of electrolyte,reduce the interphasial impedance,as well as prevent the dissolution of transition metal ions from Ni-rich cathode upon cycling at high *** finding is beneficial for the practical application of high energy density graphite/LiNi0.6Co0.2Mn0.2O2 cells.

关键词： Lithium-ion batteries Electrolyte additive P-toluenesulfonyl fluoride Electrode/electrolyte interphase Graphite/LiNi0.6Co0.2Mn0.2O2

Numerical Study on Motion Responses of Two Parallel Ships During Underway Replenishment by the Semi-Analytical HOTP Method

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China Ocean Engineering 2022年第2期36卷 233-246页

作者： YANG Yun-tao ZHU Ren-chuan MA Chao GAO Hui School of Naval Architecture and Civil Engineering Jiangsu University of Science and TechnologyZhangjiagang 215600China State Key Laboratory of Ocean Engineering Collaborative Innovation Center for Advanced Ship and Deep-Sea ExplorationSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of high Performance Ship technology(Wuhan University of technology) Ministry of EducationWuhan 430063China School of Naval Architecture Ocean and Energy Power EngineeringWuhan University of TechnologyWuhan 430063China

Motion responses of two ships advancing parallel in waves with hydrodynamic interactions are investigated in this paper. Within the framework of the frequency-domain potential flow theory, a semi-analytical higher-order translating-pulsating source(HOTP) method is presented to solve the problems of coupled radiation and diffraction potential. The method employs nine-node bi-quadratic curvilinear elements to discretize the boundary integral equations(BIEs) constructed over the mean wetted surface of the two ship hulls. In order to eliminate the numerical oscillation, analytical quadrature formulas are derived and adopted to evaluate the integrals related to the Froudedependent part of the Green’s function along the horizontal direction in the BIEs. Based on the method, a numerical program is originally coded. Through the calculations of hydrodynamic responses of single ships, the numerical implementation is proved successful. Then the validated program is applied in the investigations on the hydrodynamic interactions of two identical Wigley Ⅲ hulls and the underway replenishment of a frigate and a supply ship in waves with and without stagger, respectively. The comparison between the present computed results with experimental data and numerical solutions of other methods shows that the semi-analytical HOTP method is of higher accuracy than the pulsating source Green’s function method with speed correction and better stability than the traditional HOTP method based on Gauss quadrature. In addition, for two ships with obviously different dimensions,the influence of hydrodynamic interactions on the smaller ship is found to be more noticeable than that on the larger ship, which leads to the differences between the motions of frigate with and without the presence of supply ship.

关键词： semi-analytical HOTP method two parallel ships underway replenishment coupled motions

Influence of erbium addition on microstructure and performances of AlSi10Mg alloy prepared by selective laser melting

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Journal of Rare Earths 2024年第10期42卷 1988-1994页

作者： Bin Chen Fuzhu Wang Shiming Ren Peng Xia Zhipeng Wang Jianfei Hao Zhiping Chen Runxia Li Hongxiang Jiang research Institute of Interdisciplinary Science&School of Materials Science and Engineering Dongguan University of TechnologyDongguan523808 China College of Materials Science and Engineering Shenzhen UniversityShenzhen518060China Shi-Changxu Innovation center for advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang1i0016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China

The effect of rare earth addition on the microstructure and mechanical performances of as-cast and wrought Al alloys has been attracting increasing attention *** earth addition has great potential in modifying the structure and improving the properties of ***,there are currently few reports about the effect of rare earth addition on the microstructure and performances of Al alloys prepared via selective laser ***,AlSi10Mg alloys were manufactured using selective laser melting,and the effect of Er addition was *** results indicate that Er addition leads toα-Al refinement and modifies the minority Si *** formation of the Al_(3)Er phase induced by Er addition enhances the stren gth of the *** of the Si phase also increases *** strategy can help improve the mechanical performance of alum inum alloys prepared via selective laser melting.

关键词： Aluminum alloy Selective laser melting Rare earths Er Microstructure Tensile performance

Integrated two-phase free radical hydrogel:Safe,ultra-fast tooth whitening and antibacterial activity

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Journal of Materials Science & technology 2022年第5期100卷 59-66页

作者： Lujie Zhang Jie Pan Jue Zhang Academy for advanced Interdisciplinary Studies Peking UniversityBeijing 100871China Department of General Dentistry Peking University School and Hospital of Stomatology&National Center of Stomatology&National Clinical Research Center for Oral Diseases&National Engineering Laboratory for Digital and Material Technology of Stomatology&Beijing Key Laboratory of Digital StomatologyBeijing 100081China

The growing demand for brilliant smile and tooth whitening has led to the increasing significance of tooth whitening ***,the development of tooth whitening materials with high efficiency and safety has been considered to be an urgent ***,we report a novel tooth whitening strategy,which overcomes the limitation of conventional methods,shows excellent tooth whitening efficiency and safety,and even exhibits outstanding antibacterial *** by stomata and chloroplasts in green leaves,we have developed an integrated two-phase free radical hydrogel(TP-GEL),which integrates solid-phase and liquid-phase free radical functional components fabricated by cold plasma ***-GEL demonstrated safe and ultrafast tooth-whitening effect with or without visible light,which can be more significant than that of 30% H_(2)O_(2),the commonly whitening material in dental clinical *** importantly,we also avoid the damage to enamel,such as microhardness,roughness,surface *** from free radicals,much higher antibacterial properties than commercial products(Chlorhexidine)was *** research provides fundamental design criteria for the development of dual functional oral health care materials with advanced tooth whitening and antibacterial activity.

关键词： Tooth whitening Integrated two-phase material Free radical Safety Antibacterial activity

Effect of thickness on infrared optical property of VO2 film deposited by magnetron sputtering

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Science China(Technological Sciences) 2020年第8期63卷 1591-1598页

作者： YANG ZhenHuai YANG QiuLing YANG Lei DAI Bing XIA Fei WANG Peng GUO Shuai GAO Gang XU LiangGe ZHANG YuMin ZHU JiaQi National Key Laboratory of Science and technology on advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150080China Key Laboratory of Micro-systems and Micro-structures Manufacturing Ministry of EducationHarbin 150080China center of Analysis Measurement Harbin Institute of TechnologyHarbin 150080China

A series of VO2 films with different thicknesses(from about 25 nm to 250 nm)were prepared on sapphire substrates by radio frequency magnetron *** deposition times varied from 15 min to 150 *** metal to insulator transitions(MIT)of the films were *** optical transmittance of the films to infrared light(with a wavelength of 4.0μm)at room temperature(30℃)varied significantly with film thickness,ranging from 86.53%to 41.01%.The modulation property also changes with thickness,decreasing from 22.89%to 14.74%.The phase transition temperature remained approximately 70℃during heating,and approximately 53℃during cooling,despite a tenfold increase in the deposition time,and the resulting thickness of the *** spectroscopy of the films indicated that the intensities of the characteristic peaks corresponding to V2O5 increase with the increasing of film ***-dependent Raman spectroscopy indicated that the peaks corresponding to VO2 undergo reversible changes during heating and cooling of the films,while the peaks corresponding to V2O5 remain unchanged *** control of the V2O5 content of the films(by varying the duration of the deposition process)allows control over their transmittance and optical modulation properties without changes in the phase transition *** provides a new method of controlling the optical properties of these materials and shows promise for their potential applications in thermochromic windows.

关键词： Vanadium dioxide mid-infrared transmittance phase transition temperature magnetron sputtering