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Novel C_(sf)/SiBCN composites prepared by densifying C_(sf)/MA-SiBCN with the PIP process:Oxidation behavior and damage mechanism

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Journal of Advanced Ceramics 2024年第5期13卷 666-678页

作者： Wenhao Dou Daxin Li Bingzhu Wang Zhihua Yang Jun Chen dechang jia Ralf Riedel yu zhou institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China Key Laboratory of Advanced Structural-Functional Integration materials and Green Manufacturing technology Harbin Institute of TechnologyHarbin 150001China Chongqing Research institute of HIT Chongqing 401135China Beijing institute of Control engineering Beijing 100094China Institut für Materialwissenschaft Technische Universität DarmstadtDarmstadt D-64287Germany school of materials science and engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

To improve the oxidation resistance of short carbon fiber(C_(sf))-reinforced mechanically alloyed SiBCN(MA-SiBCN)(C_(sf)/MA-SiBCN)composites,dense amorphous C_(sf)/SiBCN composites containing both MA-SiBCN and polymer-derived ceramics SiBCN(PDCs-SiBCN)were prepared by repeated polymer infiltration and pyrolysis(PIP)of layered C_(sf)/MA-SiBCN composites at 1100℃,and the oxidation behavior and damage mechanism of the as-prepared C_(sf)/SiBCN at 1300–1600℃ were compared and discussed with those of C_(sf)/*** C_(sf)/MA-SiBCN composites resist oxidation attack up to 1400℃ but fail at 1500℃ due to the collapse of the porous framework,while the PIP-densified C_(sf)/SiBCN composites are resistant to static air up to 1600℃.During oxidation,oxygen diffuses through preexisting pores and the pores left by oxidation of carbon fibers and pyrolytic carbon(PyC)to the interior of the *** to the oxidative coupling effect of the MA-SiBCN and PDCs-SiBCN matrices,a relatively continuous and dense oxide layer is formed on the sample surface,and the interfacial region between the oxide layer and the matrix of the as-prepared composite contains an amorphous glassy structure mainly consisting of Si and O and an incompletely oxidized but partially crystallized matrix,which is primarily responsible for improving the oxidation resistance.

关键词： mechanically alloyed SiBCN(MA-SiBCN) polymer-derived ceramics SiBCN(PDCs-SiBCN) short carbon fiber-reinforced SiBCN(C_(sf)/SiBCN)composites polymer infiltration and pyrolysis(PIP) oxidation damage mechanism

Fabrication of dense SiBCN monolith at a lower temperature and its high-temperature performance

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Journal of Advanced Ceramics 2024年第8期13卷 1198-1211页

作者： Zi-Bo Niu Daxin Li dechang jia Zhihua Yang Kunpeng Lin Yan Wang Paolo Colombo Ralf Riedel yu zhou institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150080China Key Laboratory of Advanced Structural-Function Integrated materials and Green Manufacturing technology Ministry of Industry and Information TechnologyHarbin 150080China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150080China Department of Industrial engineering University of PadovaPadova 3513iItaly Department of materials science and engineering The Pennsylvania State UniversityUniversity Park 16802USA institute of materials science Darmstadt University of TechnologyDarmstadt 64287Germany school of materials science and engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

In this study,a crack-free pyrolysis process of partially cured precursor powder compacts was developed to prepare dense silicon boron carbonitride(SiBCN)monoliths at much lower temperatures(1300℃),thereby circumventing the challenges of sintering densification(>1800℃).Unlike the elastic fracture in over-cured precursors or the viscoelastic deformation in under-cured precursors,the partially cured precursor,exhibiting elastic-plastic deformation behavior,facilitates limited nanoscale pore formation in a dense structure,achieving a balance between crack-free pyrolysis and *** to SiBCN derived from the over-cured precursor(σ=~159 MPa,K_(IC)=1.9 MPa:m^(1/2),Vickers hardness(HV)=7.8 GPa,and E=122 GPa),the resulting SiBCN monolith exhibited significantly improved mechanical properties(σ=~304 MPa,K_(IC)=3.7 MPa-m12,HV=10.6 GPa,and E=161 GPa)and oxidation *** addition,this study investigated the high-temperature performance of SiBCN monoliths,including crystallization and oxidation,and determined the oxidation kinetics induced by pore structure healing and the different oxidation mechanisms of Si-C-N and B-C-N clusters in the amorphous *** to its unique composition and structure,the SiBCN ceramic oxide layer exhibits exceptional self-healing effects on repairing the nanoporous system in the initial stage and shows outstanding high-temperature stability during prolonged oxidation,mitigating adverse effects from bubble formation and *** to the nanoporous structure,the oxidation rate is initially controlled by gas diffusion following a linear law before transitioning to oxide layer diffusion characterized by a parabolic ***,due to different valence bond configurations,Si-C-N transforms into an amorphous SiCNO structure after phase separation,unlike the nucleation and growth of residual B-N-C.

关键词： silicon boron carbonitride(SiBCN)ceramics crack-free pyrolysis amorphous structure oxidation mechanisms kinetic law

Preparation of Strontium Bismuth Tantalum (SBT) Fine Powder by Sol-Gel Process Using Bismuth Subnitrate as Bismuth Source

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Journal of materials science & technology 2001年第1期17卷 25-26页

作者： Wen WANG yu zhou Sheng CHEN Feng YE and dechang jia school of materials science and engineering, P.O.Box 433, harbin institute of technology, harbin 150001, China harbin Inst Technol Sch Mat Sci & Engn Harbin 150001 Peoples R China

Strontium bismuth tantalum (SBT) fine power was prepared by Sol-Gel method. Pentaethoxy tantalum, strontium acetate and bismuth subnitrate were used as raw materials, and were dissolved in proper order in ethylene glycol to form transparent sol. The mixed precursor was dried at 80℃ and annealed at 800℃ for 1 h. Crystallized nanometer sized SBT fine powder was obtained and characterized by XRD.

关键词： SBT Preparation of Strontium Bismuth Tantalum Ta Fine Powder by Sol-Gel Process Using Bismuth Subnitrate as Bismuth Source

Alignment error modeling and control of a double-sided microlens array during precision glass molding

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Microsystems & Nanoengineering 2024年第2期10卷 311-322页

作者： Zihao Zeng Tianfeng zhou Qian yu jia zhou Gang Wang Qiuchen Xie Zifan Wang Xiaoqiang Yao yubing Guo school of Medical technology Beijing Institute of TechnologyNo.5 Zhongguancun South StreetHaidian DistrictBeijing100081China school of Mechanical engineering Beijing Institute of TechnologyNo.5 Zhongguancun South StreetHaidian DistrictBeijing100081China

Double-sided microlens arrays(DSMLAs)include combinations of two single-sided MLAs to overcome positioning errors and greatly improve light transmissivity compared to other types of *** glass molding(PGM)is used to fabricate DSMLAs,but controlling alignment errors during this process is *** this paper,a mold assembly was manufactured with a novel combination of materials to improve the alignment accuracy of mold cores during PGM by using the nonlinear thermal expansion characteristics of the various materials to improve the DSMLA alignment *** establishing a mathematical model of the DSMLA alignment error and a thermal expansion model of the mold-sleeve pair,the relationship between the maximum alignment error of the DSMLA and the mold-sleeve gap was *** research provides a method to optimize the mold-sleeve gap and minimize the alignment error of the *** measured DSMLA alignment error was 10.56μm,which is similar to the predicted maximum alignment *** measurements showed that the uniformity of the homogenized beam spot was 97.81%,and the effective homogeneous area accounted for 91.66%of the total *** proposed method provides a novel strategy to improve the performance of DSMLAs.

关键词： sided alignment error

Modulating p-type doping of two-dimensional material palladium diselenide

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Nano Research 2024年第4期17卷 3232-3244页

作者： jiali Yang yu Liu En-Yang Wang Jinbo Pang Shirong Huang Thomas Gemming Jinshun Bi Alicja Bachmatiuk Hao jia Shu-Xian Hu Chongyun jiang Hong Liu Gianaurelio Cuniberti Weijia zhou Mark H Rümmeli institute for Advanced Interdisciplinary Research(iAIR) University of JinanJinan 250022China institute for materials Chemistry Leibniz Institute for Solid State and Materials Research Dresden(IFW Dresden)20 Helmholtz StrasseDresden 01069Germany State Key Lab of Transducer technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China College of Energy Soochow Institute for Energy and Materials Innovations Soochow UniversitySuzhou 215006China Key Laboratory of Advanced Carbon materials and Wearable Energy Technologies of jiangsu Province Soochow UniversitySuzhou 215006China school of Integrated Circuits University of Chinese Academy of SciencesBeijing 101408China institute of Microelectronics of Tianjin Binhai New Area Tianjin 300451China institute of Microelectronics Chinese Academy of SciencesBeijing 100029China Lukasiewicz Research Network PORT Polish Center for Technology DevelopmentStablowicka 147Wroclaw 54-066Poland school of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China College of electronic information and optical engineering Nankai UniversityTianjin 300350China Centre of Polymer and Carbon materials Polish Academy of SciencesM.Curie Sklodowskiej 34Zabrze 41-819Poland Center for Energy and Environmental Technologies VŠB-Technical University of Ostrava17.Listopadu 15Ostrava 70833Czech Republic State Key Laboratory of Crystal materials Center of Bio&Micro/Nano Functional MaterialsShandong UniversityJinan 250100China Dresden Center for Computational materials science Technische Universität DresdenDresden 01062Germany Dresden Center for Intelligent materials(GCL DCIM) Technische Universität DresdenDresden 01062Germany institute for materials science and Max Bergmann Center of Biomaterials Technische Universität DresdenDresden 01069Germany Center for Advancing Electronics Dresden Technische Universität DresdenDresden 01069Germany

The van der Waals heterostructures have evolved as novel materials for complementing the Si-based semiconductor ***-10 noble metal dichalcogenides(e.g.,PtS_(2),PtSe_(2),PdS_(2),and PdSe_(2))have been listed into two-dimensional(2D)materials toolkit to assemble van der Waals *** them,PdSe_(2) demonstrates advantages of high stability in air,high mobility,and wide tunable ***,the regulation of p-type doping of PdSe_(2) remains unsolved problem prior to fabricating p–n junction as a fundamental platform of semiconductor ***,a quantitative method for the controllable doping of PdSe_(2) is yet to be *** this study,the doping level of PdSe_(2) was correlated with the concentration of Lewis acids,for example,SnCl_(4),used for *** the transfer characteristics,the threshold voltage(the gate voltage corresponding to the minimum drain current)increased after SnCl_(4) soaking ***_(2) transistors were soaked in SnCl_(4) solutions with five different *** threshold voltages from the as-obtained transfer curves were extracted for linear fitting to the threshold voltage versus doping concentration correlation *** study provides in-depth insights into the controllable p-type doping of PdSe_(2).It may also push forward the research of the regulation of conductivity behaviors of 2D materials.

关键词： two-dimensional(2D)materials Lewis acid treatment p-type doping field-effect transistors transfer characteristic

The effect of secondary phase on corrosion behaviors of the titanium–zirconium–molybdenum alloy

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Tungsten 2024年第2期6卷 342-354页

作者： Song-Wei Ge Ping Hu Jie Deng Shi-Lei Li Hai-Rui Xing jia-yu Han Xing-jiang Hua Li Wang Jun-zhou Yang Bo Jin Wen Zhang Kuai-She Wang school of Metallurgy engineering Xi’an University of Architecture and TechnologyXi’an 710055China National and Local Joint engineering Research Center for Functional materials Processing Xi’an University of Architecture and TechnologyXi’an 710055China Western Xinxing Rare and Precious Metals Co. Ltd.Shangluo 726000China Northwest institute for Non-Ferrous Metal Research Xi’an 710016China

As the range of applications for molybdenum and its alloys has expanded,the corrosive environment for molybdenum alloys has become more *** the past,the content of doping elements has been studied to investigate their infl uence on the corrosion performance of titanium–zirconium–molybdenum(TZM)*** this paper,it is considered that the second phase in the alloy is the main factor aff ecting the corrosion performance of TZM *** comparing the corrosion behavior of molybdenum metal and TZM alloy,the eff ect of the secondary phase on corrosion behaviors of TZM alloy has been *** results show that the second phase reduces the corrosion resistance of the TZM *** potential of the second phase is 73.7 mV higher than that of the Mo matrix,which contributes to the formation of microscopic electric *** the action of microscopic electric couples,pitting corrosion is preferentially formed at the interface between the second phase and the matrix,which accelerates the corrosion of the *** paper provides a theoretical basis for the application of TZM alloys in corrosive environments.

关键词： Secondary phase Electrochemical corrosion Titanium–zirconium–molybdenum(TZM) Galvanic corrosion Corrosion resistance

Mechanical Properties and Thermal Shock Resistance of SrAl_(2)Si_(2)O_(8) Reinforced BN Ceramic Composites

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无机材料学报 2024年第10期39卷 1182-1188页

作者： WANG Bo CAI Delong ZHU Qishuai LI Daxin YANG Zhihua DUAN Xiaoming LI Yanan WANG Xuan jia dechang zhou yu International Joint Laboratory of Advanced Nanomaterials of Heilongjiang Province College of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China Key Laboratory of Advanced Structural-Functional Integration materials School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China China Resources Cement technology R&D Co. LtdGuangzhou 510000China The First Military Representative Office of the Army Equipment Department in Beijing Beijing 100072China The Fourth System Design Department Fourth AcademyChina Aerospace Science and Industry Corporation LimitedBeijing 100048China school of materials science and engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

Hexagonal boron nitride(h-BN)ceramics have become exceptional materials for heat-resistant components in hypersonic vehicles,owing to their superior thermal stability and excellent dielectric ***,their densification during sintering still poses challenges for researchers,and their mechanical properties are rather *** this study,SrAl_(2)Si_(2)O_(8)(SAS),with low melting point and high strength,was introduced into the h-BN ceramics to facilitate the sintering and reinforce the strength and ***,BN-SAS ceramic composites were fabricated via hot press sintering using h-BN,SrCO_(3),Al_(2)O_(3),and SiO_(2) as raw materials,and effects of sintering pressure on their microstructure,mechanical property,and thermal property were *** thermal shock resistance of BN-SAS ceramic composites was *** show that phases of as-preparedBN-SAS ceramic composites are h-BN and h-SrAl_(2)Si_(2)O_(8).With the increase of sintering pressure,the composites’densities increase,and the mechanical properties shew a rising trend followed by a slight *** a sintering pressure of 20 MPa,their bending strength and fracture toughness are(138±4)MPa and(1.84±0.05)MPa·m^(1/2),*** sintered at 10 MPa exhibit a low coefficient of thermal expansion,with an average of 2.96×10^(-6) K^(-1) in the temperature range from 200 to 1200℃.The BN-SAS ceramic composites prepared at 20 MPa display higher thermal conductivity from 12.42 to 28.42 W·m^(-1)·K^(-1) within the temperature range from room temperature to 1000℃.Notably,BN-SAS composites exhibit remarkable thermal shock resistance,with residual bending strength peaking and subsequently declining sharply under a thermal shock temperature difference ranging from 600 to 1400℃.The maximum residual bending strength is recorded at a temperature difference of 800℃,with a residual strength retention rate of 101%.As the thermal shock temperature difference increase,the degree of oxida

关键词： BN matrix composite hot-press sintering mechanical property thermal shock resistance service reliability

Enhanced mechanical properties and thermal shock resistance of Si_2BC_3N ceramics with SiC coated MWCNTs

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Journal of Advanced Ceramics 2019年第1期8卷 121-132页

作者： Ning LIAO dechang jia Zhihua YANG yu zhou institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of Technology Key Laboratory of Advanced Structure-Function Integrated materials and Green Manufacturing technology Ministry of Industry and Information Technology

Bulk Si_2 BC_3 N ceramics were reinforced with SiC coated multi-walled carbon nanotubes(MWCNTs). The phase compositions, mechanical properties, and thermal shock resistance, as well as the oxidation resistance of the designed Si_2 BC_3 N ceramics were comparatively investigated. The results show that nano SiC coating can be formed on MWCNTs through pyrolyzing polysilazane, which improves the oxidation resistance of MWCNTs. A stronger chemical bonding is formed between the SiC coated MWCNTs and SiC particles, contributing to improved flexural strength(532.1 MPa) and fracture toughness(6.66 MPa m1/2). Besides, the 2 vol% SiC coated MWCNTs reinforced Si_2 BC_3 N ceramics maintains much higher residual strength(193.0 MPa) after thermal shock test at 1000 ℃.The enhanced properties should be attributed to:(1) the breaking of MWCNTs and the debonding between MWCNTs and SiC interfaces, which leads to more energy dissipation;(2) the rough surfaces of SiC coated MWCNTs increase the adhesion strength during the "pull out" of MWCNTs.

关键词： Si2BC3N ceramics SiC coated MWCNTs mechanical properties thermal shock resistance

Antibacterial and angiogenic dual-functional fibrous membrane dressing for infected wound healing

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Biomedical engineering Communications 2024年第1期3卷 4-14页

作者： Chao zhou Che Zhao Hao-yu Dai Tian-Jun Zhu jia-Pei Yao Li Chen Jing-Jing Wen jia Ling Celestine Loh Xin-Die zhou Yong Huang school of Medical and Health engineering Changzhou UniversityChangzhouJiangsu 213164China school of Aerospace and Mechanical engineering Changzhou Institute of TechnologyChangzhouJiangsu 213032China Department of Orthopedics The Affiliated Changzhou Second People's Hospital of Nanjing Medical UniversityChangzhou Medical CenterNanjing Medical UniversityChangzhou 213000China Duke-NUS Graduate Medical school National University of SingaporeKent Ridge 169547Singapore

Background:Skin,being a vital organ that regulates physiological responses in the human body,is prone to injury from external environmental *** full-thickness skin defects becomes especially challenging when infections and vascular injuries are *** wound dressings with single functions,such as antibacterial or angiogenic properties,fall short in achieving rapid wound *** address this,there is a need to develop wound dressing materials that possess both effective antibacterial and angiogenic ***:In this study,we utilized electrospinning technology to fabricate hyaluronic acid-cellulose acetate fibrous membrane dressings,incorporating poly(ionic liquid)as an antibacterial polymer and deferoxamine as an angiogenic ***:The resulting fibrous membrane dressing contained poly(ionic liquid)and deferoxamin showcased a microporous structure,drug-releasing capabilities,and excellent air *** not only demonstrated highly effective antibacterial properties but also exhibited remarkable angiogenesis,thereby promoting the healing of full-thickness skin defect wounds in both in vitro and in vivo ***:These findings highlight the immense potential of this wound dressing material for future clinical applications.

关键词： electro spinning antibacterial polymer angiogenesis wound healing membrane dressing