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Nonclassical crystallization of zinc carbonate hydroxide hydrate nanofilm mediated by calcium ions

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Progress in Natural Science:Materials International 2022年第5期32卷 579-585页

作者： Qihang Wang Bicheng Yuan Wenduo Gao Huifeng Hu Meng Cai Zhaoyong Zou Zhengyi Fu State Key laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology hubei longzhong laboratory

To satisfy the demand of zinc oxide(ZnO) with advanced muti-functional properties, significant efforts have been made in synthesizing ZnO with various structure and morphology. In particular, hydrothermal method has attracted considerable attentions, in which Zn4CO3(OH)6·H2O(ZCHH) is commonly found as a metastable precursor. However, the formation and crystallization mechanisms of ZCHH are still lacking and urgently needed. In the present study, the crystallization pathway of ZCHH was systematically investigated, and the results demonstrate that the amorphous zinc carbonate(AZC) was an even more unstable precursor. AZC nanoparticles typically aggregated to form one-dimensional(1D) ZCHH nanorods, however, two-dimensional(2D) ZCHH nanofilms were obtained in the presence of a certain concentration of calcium ion. The results suggest that calcium ions could promote the partial dissolution of AZC and facilitate the aggregation of AZC nanoparticles to form crystalline nanofilm. Moreover, 2D ZnO nanofilms could be obtained by heat treatment of the ZCHH nanofilms. The calcium ion mediated nonclassical crystallization pathway provides inspiration for fabrication of ZnO with controlled morphology and offers new opportunities for inorganic regulated material synthesis.

关键词： Zn4CO3(OH)6·H2O Calcium ion Crystallization ZnO nanofilm

Radial envelope forming mechanism and process design method for cylindrical rings with thin wall and high web ribs

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Chinese Journal of Aeronautics 2023年第12期36卷 461-476页

作者： Xinghui HAN Yanlei MIN Wuhao ZHUANG Lin HUA Duanyang TIAN Zushen DENG Ningbo LIU hubei Key laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Longzhong LaboratoryXiangyang 441000China

Cylindrical rings with thin wall and high web ribs(CRTWHWR)are widely used as the key load bearing structures such as rocket body and space station cabin in aerospace ***,it is still difficult to efficiently manufacture CRTWHWR with high performance because of their extreme geometry with thin-walled skins,high web ribs and large *** this paper,a novel radial envelope forming process is put forward to efficiently achieve the plastic forming of CRTWHWR with high ***,the principle of radial envelope forming process is ***,an efficient design method for the tool motion and geometry is proposed based on the reverse envelope principle,i.e.,CRTWHWR is adopted to reversely envelope the tool and thus the tool which does not interfere with CRTWHWR can be efficiently obtained in a single ***,a reasonable 3D FE model of the radial envelope forming process of CRTWHWR is established and the radial envelope forming mechanism of CRTWHWR is comprehensively *** the FE simulation and experiments with material of plastic mud,a typical CRTWHWR with diameter of 300 mm,axial height of 192 mm,the maximum rib height of 25 mm,the minimum rib thickness of 3 mm and skin thickness of 5 mm is radial envelope formed,i.e.,the ratio of the maximum rib height to the minimum rib thickness reaches 8.33,the ratio of the maximum rib height to skin thickness reaches 5 and the ratio of diameter to the minimum rib thickness reaches *** above results verify that the proposed radial envelope forming process has great potentials in efficiently manufacturing CRTWHWR with extreme geometry.

关键词： Radial envelope forming Cylindrical ring with thin wall and high web ribs Forming mechanism FE simulation Tool design

Effects of Strain Channel on Electron Irradiation Tolerance of InP-based HEMT Structures

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原子能科学技术 2023年第12期57卷 2288-2294页

作者： FANG Renfeng CAO Wenyu WEI Yanfeng WANG Yin CHEN Chuanliang YAN Jiasheng XING Yan LIANG Guijie ZHOU Shuxing hubei Key laboratory of Low Dimensional Optoelectronic Materials and Devices Hubei University of Arts and ScienceXiangyang 441053China hubei Key laboratory of High Power Semiconductor Technology Hubei TECH Semiconductor Co.LtdXiangyang 441021China hubei longzhong laboratory Xiangyang 441000China

The introduction of strain In_(x)Ga_(1-x)As channel with high In content increases the confinement of the two-dimensional electron gas(2DEG)and further improves the high-frequency performance of InGaAs/InAlAs/InP *** effect of In_(x)Ga_(1-x)As channel with different In contents on electron irradiation tolerance of InP-based HEMT structures in terms of 2DEG mobility and density has been *** experiment results show that,after the same high electron irradiation dose,the 2DEG mobility and density in InP-based HEMT structures with strain In_(x)Ga_(1-x)As(x>0.53)channel decrease more dramatically than that without strain In_(0.53)Ga_(0.47)As ***,the degradation of 2DEG mobility and density becomes more severe as the increase of In content and strain in the In_(x)Ga_(1-x)As *** research results can provide some suggestions for the design of radiation-resistant InP-based HEMTs.

关键词： InP-based HEMT strain channel two-dimensional electron gas electron irradiation

Phase-field lattice-Boltzmann study on fully coupled thermal-solute-convection dendrite growth of Al-Cu alloy

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China Foundry 2024年第2期21卷 125-136页

作者： Yin-qi Qiu Meng-wu Wu Xun-peng Qin Shou-mei Xiong hubei Key laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China hubei longzhong laboratory Xiangyang 441000HubeiChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

Dendrite growth is a complex liquid-solid phase transition process involving multiple physical factors.A phase-field lattice-Boltzmann method was developed to simulate the two-and three-dimension dendrite growth of Al-Cu *** effect of fully coupled thermal-solute-convection interaction on the dendrite growth was investigated by incorporating a parallel-adaptive mesh refinement algorithm into the numerical *** accurately reproducing the latent heat release,solute diffusion and convective transport behaviors at the liquidsolid interface,the interaction mechanism among thermal-solute-convection transport as well as their coupling effects on the dendrite growth dynamics were *** simulation results show that the release of latent heat slows down the dendrite growth rate,and both natural and forced convection disrupt the symmetrical growth of *** combination makes the growth of dendrites more complex,capturing important physical aspects such as recalescence,dendrite tip splitting,dendrite tilting,dendrite remelting,and solute plume in the simulation *** on the robustness and powerful ability of the numerical model,the formation mechanisms of these physical aspects were revealed.

关键词： simulation phase field dendrite growth thermal-solute-convection interaction

Effect of Mn addition on microstructure and mechanical properties of GX40CrNiSi25-12 austenitic heat resistant steel

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China Foundry 2024年第3期21卷 205-212页

作者： Guan-yu Jiang Meng-wu Wu Xiao-guang Yang Hui Wang Yu-yuan Zhu hubei Key laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China hubei longzhong laboratory Xiangyang 441000HubeiChina Wescast Industries(China)Co. Ltd.Wuhan 430100China

Three types of steels were designed on the basis of GX40CrNiSi25-12 austenitic heat resistant steel by adding different Mn contents(2wt.%,6wt.%,and 12wt.%).Thermodynamic calculation,microstructure characterization and mechanical property tests were conducted to investigate the effect of Mn addition on the microstructure and mechanical properties of the austenitic heat resistant *** show that the matrix structure in all the three types of steels at room temperature is completely *** NbC and M_(23)C_(6)precipitate at grain boundaries of austenite *** the increase of Mn content,the number of carbides increases and their distribution becomes more *** the Mn content increases from 1.99%to 12.06%,the ultimate tensile strength,yield strength and elongation increase by 14.6%,8.0%and 46.3%,*** improvement of the mechanical properties of austenitic steels can be explained by utilizing classic theories of alloy strengthening,including solid solution strengthening,precipitation strengthening,and grain *** increase in alloy strength can be attributed to solid solution strengthening and precipitation strengthening caused by the addition of *** improvement of the plasticity of austenitic steels can be explained from two aspects:grain refinement and homogenization of precipitated phases.

关键词： austenitic heat resistant steel manganese microstructure mechanical properties

Enhanced Photocatalytic Activity of Z-scheme Meso-BiVO_(4)-Au-CdS for Degradation of Rhodamine B

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 869-876页

作者：张雁伟 WANG Yanze LI Junguo XIE Jingjing 王文宣 FU Zhengyi State Key laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China hubei longzhong laboratory Xiangyang 441000China

We synthesized BiVO_(4)mesocrystals with ordered assembly structure,and studied the structural order and the relationship between the photodegradation of Rhodamine *** nanoparticles(NPs)were successfully loaded onto Meso-BiVO_(4)by light-assisted induction,and Cd nanoparticles were further selected to be deposited on Au nanoparticles to form Z-scheme photocatalyst Meso-BiVO_(4)-Au-CdS *** try and propose to analyze its ordered assembly structure by XRD for the first *** results show that Meso-BiVO_(4)is a mesocrystal with highly exposed(001)plane and directional assembly *** charge separation efficiency of all samples was studied by PL *** results show that the Z-scheme Meso-BiVO_(4)-Au-CdS can promote the charge separation and obtain the best carrier separation ***,it has the best photocatalytic activity in the experiment of photocatalytic degradation of rhodamine *** main active species in the degradation process were confirmed by free radical trapping experiment,and the degradation mechanism was put forward.

关键词： biomineralization photosynthesis mesocrystal photocatalysis TiO_(2) BiVO_(4)

Etching Mechanism of Ti_(3)C_(2)Cl_(2) MXene Phases by CuCl_(2)-Lewis Molten Salt Method

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 863-868页

作者：严明 ZHU Yu HUANG Jiangtao CHEN Haoyu DENG Yuxiao CHEN Yanlin 王娟 Jan-Michael Albina hubei Provincial Key laboratory of Green Materials for Light Industry Hubei University of TechnologyWuhan 430068China New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base Hubei University of TechnologyWuhan 430068China hubei longzhong laboratory Xiangyang 441000China

We described a method for obtaining fluorine-free Ti_(3)C_(2)Cl_(2)MXene phases by melting copper in CuCl_(2)instead of aluminum in Ti_(3)AlC_(2).XRD results show that when molten salt CuCl_(2)etches Ti_(3)AlC_(2),it forms an intermediate product Ti_(3)CuC_(2),and then reacts with Ti_(3)CuC_(2)to obtain Ti_(3)C_(2)Cl_(2).The reaction of Ti_(3)AlC_(2)and CuCl_(2)at a temperature of 800℃for 2 h to obtain Ti_(3)C_(2)Cl_(2)with an optimal lamellar structure is shown in SEM *** pseudopotential plane-wave(PP-PW)method is used to calculate on the electronic *** etching mechanism is investigated by the total energies of each *** chemical reaction of Ti_(3)AlC_(2)and CuCl_(2)will first become Ti_(3)CuC_(2)and Cu,and then become Ti_(3)C_(2)Cl_(2)during the Lewis acid etching process,which are consistent with the experimental results.

关键词： molten salt method CuCl_(2) MXene first-principles calculations etching mechanism

Modelling and analysis of metal flowing behaviors in constraining ring rolling of tapered ring with thin wall and three high ribs

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Chinese Journal of Aeronautics 2023年第6期36卷 476-492页

作者： Lin HUA Duanyang TIAN Xinghui HAN Wuhao ZHUANG hubei Key laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China hubei longzhong laboratory Xiangyang 441000China School of Automotive Engineering Wuhan University of TechnologyWuhan 430070China

Tapered ring with thin wall and three high ribs(TRTWTHR),showing complicated geometry(wall thickness is less than 4 mm and rib height exceeds 20 mm),is extensively utilized to fabricate the critical structural parts of aerospace equipment such as spacecraft cabin,rocket body and fuel tank because of light weight and high carrying *** to fabricate TRTWTHR with high performance is a critical problem that aerospace area needs to *** this work,constraining ring rolling(CRR)technique is first adopted to form *** metal streamlines(UMS)and uncoordinated growth of three ribs easily occur in CRR of TRTWTHR,which makes the forming quality of TRTWTHR difficult to be *** with this difficulty,an analytical model that can predict UMS and the height of three ribs in CRR of TRTWTHR is established so as to guide the process design of ***,the reliability of the established analytical model and the feasibility of CRR of TRTWTHR are confirmed by FE simulation and ***,using the established analytical model,the window of UMS occurring relevant to the tapered angle of TRTWTHR and the location of the rib of middle end is ***,three uncoordinated growth modes among three ribs are found when the width of three ribs is identical and UMS do not occur,and the mechanisms of three uncoordinated growth modes are revealed.

关键词： Analytical model Constraining ring rolling Growth of three ribs Metal streamlines Tapered ring with thin wall and three high ribs

Grain-refining fabrication of nanocrystalline(La_(0.2)Nd_(0.2)Sm_(0.2)Gd_(0.2)Eu_(0.2))_(2)Zr_(2)O_(7)high-entropy ceramics by ultra-high pressure sintering

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Journal of Materials Science & Technology 2023年第36期167卷 205-212页

作者： Zhangtian Wu Wei Ji Jinyong Zhang Yanan Yuan Ji Zou Weimin Wang Zhengyi Fu State Key laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China hubei longzhong laboratory Wuhan University of Technology Xiangyang Demonstration ZoneXiangyang 441000China

As an important A_(2)B_(2)O_(7)-type ceramic,(La_(0.2)Nd_(0.2)Sm_(0.2)Gd_(0.2)Eu_(0.2))_(2)Zr_(2)O_(7)high-entropy pyrochlore pos-sesses promising properties such as high melting point,high chemical durability,and low thermal ***,the low sintering ability limits its application in thermal barrier coating and radioactive waste *** usually needs long-term high-temperature soaking to achieve full density,but with inevitable grain *** this work,dense and grain-refined nanocrystalline(La_(0.2)Nd_(0.2)Sm_(0.2)Gd_(0.2)Eu_(0.2))_(2)Zr_(2)O_(7)ceramics were prepared with ultra-high pressure sintering(UHPS)method under 10 GPa at a low temperature of 800℃.The densification behavior,microstructure evo-lution,and properties of the UHPS-ed samples were then *** grain size of as-prepared(La_(0.2)Nd_(0.2)Sm_(0.2)Gd_(0.2)Eu_(0.2))_(2)Zr_(2)O_(7)ceramic was only 151 nm,which is 40%smaller than that of raw *** addition,it exhibited advantageous properties including both high hardness and aqueous *** deformation under ultra-high pressure was believed as the dominant densification mechanism responsible for grain refinement and property improvement.

关键词： High-entropy ceramics Ultra-high pressure sintering Grain refining Nanocrystalline Plastic deformation