检索结果-南通市图书馆

Profiling interfacial reaction features between diamond and Cu-Sn-Ti active filler metal brazed at 1223 K

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第36期131卷 100-105页

作者： Yonggang Fan Kenan Li Haodong Li co.g Wang Key Laboratory for Eco.ogical Metallurgy of Multimetallic Mineral(Ministry of Education) School of MetallurgyNortheastern UniversityShenyang 110819China State Key Laboratory of Superabrasives Zhengzhou Research Institute for Abrasives&Grinding Co.Ltd.Zhengzhou 450001China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Diamond/Cu-Sn-Ti co.posites have been successfully prepared by co.d-press forming in co.junction with high-temperature vacuum active brazing at 1223 *** wetting behaviors between diamond and filler metal,interfacial characteristics of the reaction layer,and wear resistance of the bulky co.posite have been fully *** is revealed that all diamond particles can only be fully co.ted when the TiH_(2)co.tent exceeds 5 wt%,below which sharp edges on diamond can still be *** interfacial reaction layer is found to be co.posed of TiC,the thickness of which is demonstrated to increase as a function of TiH_(2)co.tent,arriving at the peak value of 1.70μm and remaining almost co.stant *** is further shown that the maximum wear resistance occurs approaching 5 wt%TiH_(2)*** mechanisms responsible for such interesting phenomena have been postulated.

关键词： Diamond Cu-Sn-Ti Brazing Interfacial layer Powder metallurgy

Structure-dependent electromagnetic wave absorbing properties of bowl-like and honeyco.b TiO_(2)/CNT co.posites

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第14期109卷 105-113页

作者： Hua Jian Qinrui Du Qiaoqiao Men Li Guan Ruosong Li Bingbing Fan Xin Zhang Xiaoqin Guo Biao Zhao Rui Zhang Henan Key Laboratory of Aeronautical Materials and Application Technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhou 450046China School of Chemical Engineering Northwest UniversityXi’an 710069China Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China zhengzhou research institute for abrasives&grinding co. Ltd.Zhengzhou 450001China School of Material Science and Engineering Luoyang Institute of Science and TechnologyLuoyang 471023China

Materials that can efficiently absorb electromagnetic waves(EMWs)are required to deal with electromagnetic *** design appears to be an efficient way to improve the EMW-absorption performance of such materials,particularly when adjustment of the co.stitution or mixing ratio is *** this study,bowl-like and honeyco.b titanium dioxide/carbon nanotube(TiO_(2)/CNT)co.posites with different CNT co.tents were fabricated using the methods of hierarchical and mixing vacuum-assisted filtration,*** to the honeyco.b structure,the bowl-like structure simultaneously facilitated greater interfacial polarization and co.duction loss in favor of dielectric polarization,and augmented multiple *** high porosity of the honeyco.b structure was co.ducive to optimizing the impedance matching *** bowl-like TiO_(2)/CNT co.posite exhibited a minimum reflection loss(RL_(min))of-38.6 dB(1.5 mm)with a wide effective absorption band(EAB;co.b TiO_(2)/CNT co.posite showed an RLminof-34.8 dB(2.1 mm)with an EAB of 4.3 *** required mixing ratio in the matrix was only 15 wt%,outperforming that of the most closely related ***,both the bowl-like and honeyco.b TiO_(2)/CNT co.posites are ideal candidates for light-weight and highly efficient EMW-absorbing materials.

关键词： Bowl-like structure Honeyco.b structure TiO_(2)/CNT co.posite Electromagnetic wave absorption

Fretting wear behaviour of machined layer of nickel-based superalloy produced by creep-feed profile grinding

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2022年第10期35卷 401-411页

作者： Weijie KUANG Qing MIAO Wenfeng DING Yanjun ZHAO Biao ZHAO Xuebing WEN Shaopeng LI National Key Laboratory of Science and Technology on Helico.ter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China co.lege of Mechanical Engineering Suzhou University of Science and TechnologySuzhou 215009China State Key Laboratory of Super abrasives Zhengzhou Research Institute for Abrasive&Grinding Co.LtdZhengzhou 450001China AECC Xi'An Aero-Engine LTD Xi'an 710021China

Fretting wear has an adverse impact on the fatigue life of turbine blade *** current work is to co.paratively investigate the fretting wear behaviour of the nickel-based superalloy surfaces produced by polishing and creep-feed profile grinding,respectively,in terms of surface/subsurface fretting damage,the friction co.fficient,wear volume and wear *** results show that the granulated tribolayer aggravates the workpiece wear,while the flat co.pacted tribolayer enhances the wear resistance ability of workpiece,irrespective of whether the workpiece is processed by polishing or ***,the wear behaviors of tribolayers are *** the polished surface,when the normal load exceeds 100 N,the main defects are crack,rupture,delamination and peeling of workpiece materials;the wear mechanism changes from severe oxidative wear to fatigue wear and abrasive wear when the loads increase from 50 to 180 *** for the ground surface,the main wear mechanism is abrasive ***,the ground surface possesses better wear-resistant ability than the polished surface because the former has the lower values in co.fficient friction(0.23),wear volume(0.06×10^(6)μm^(3))and wear rate(0.25×10^(-16)Pa^(-1)).Finally,an illustration is given to characterize the evolution of wear debris on such nickel-based superalloy on the ground surface.

关键词： Creep-feed profile grinding Fretting wear Nickel-based superalloy Tribolayer Wear debris

Material removal mechanisms in ultrasonic vibration-assisted high-efficiency deep grindingγ-TiAl alloy

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第11期37卷 462-476页

作者： Tao CHEN Xiaowei WANG Biao ZHAO Wenfeng DING Mingyue XIONG Jiuhua XU Qi LIU Dongdong XU Yanjun ZHAO Jianhui ZHU National Key Laboratory of Science and Technology on Helico.ter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China Centre for Precision Manufacturing University of StrathclydeGlasgow G11XJUK School of Mechanical Engineering Tongji UniversityShanghai 201804China State Key Laboratory for High Performance Tools Zhengzhou Research Institute for Abrasives and Grinding Co.LTDZhengzhou 450001China

Gamma titanium-aluminum intermetallic co.pounds(γ-TiAl)have gained co.siderable attentions in the aerospace industry due to their exceptional thermal resilience and co.prehensive attributes,making them a prime example of lightweight and advanced *** address the frequent occurrence of burns and severe tool deterioration during the process of high-efficiency deep grinding(HEDG)onγ-TiAl alloys,ultrasonic vibration-assisted high-efficiency deep grinding(UVHEDG)has been *** indicate that in UVHEDG,the grinding temperature is on average 15.4%lower than HEDG due to the employment of ultrasonic vibrations,enhancing co.lant penetration into the grinding area and thus reducing heat ***,UVHEDG possesses superior performance in terms of grinding forces co.pared to *** the material removal volume(MRV)increases,the tangential grinding force(F_(t))and normal grinding force(F_(n))of UVHEDG increase but to a lesser extent than in HEDG,with an average reduction of16.25%and 14.7%,*** primarily experiences microfracture of grains,whereas HEDG undergoes large-scale wear later in the process due to increased grinding *** surface roughness(R_(a))characteristics of UVHEDG are superior,with the average value of R_(a)decreasing by 46.5%co.pared to HEDG as MRV *** surface morphology in UVHEDG exhibits enhanced smoothness and a shallower layer of plastic *** chips generated by UVHEDG show a more shear-like shape,with the applied influence of ultrasonic vibration on chip morphology,thereby impacting material removal *** aforementioned findings co.tribute to enhanced machining efficiency and product quality ofγ-TiAl alloys after employing ultrasonic vibrations into HEDG.

关键词： Ultrasonic vibration-assisted high-efficiency deep grinding grinding temperature grinding forces Surface roughness Chip formation

Extraordinary toughening enhancement in nonstoichiometric vanadium carbide

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第2期97卷 176-181页

作者： Chong Peng Hu Tang Changjian Geng Pengjie Liang Biao Wan Yujiao Ke Yuefeng Wang Peng Jia Wenfeng Peng Lina Qiao Kenan Li Xiaohong Yuan Yucheng Zhao Mingzhi Wang State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China Academy for Advanced Interdisciplinary Studies Southern University of Science and TechnologyShenzhen 518055China Key Laboratory of Material Physics Ministry of EducationSchool of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450052China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China Center for High Pressure Science and Technology Advanced research Beijing 100190China Hebei co.struction Material Vocational and Technical co.lege Qinhuangdao 066004China State Key Laboratory of Superabrasives Zhengzhou Research Institute for Abrasives&Grinding Co.Ltd.Zhengzhou 450001China

*** Fracture toughness is the ability of materials against both the initiation and propagation of cracks[1],which is a crucial mechanical property for safety-critical applications of structural *** the yield strength of ceramics is significantly higher than that of metallic materials,the fracture toughness is severely lower than that of metallic materials due to the strongly directional co.alent bonding[1-3].For a long time,how to improve the fracture toughness of ceramics without the deterioration of strength(or hardness)has been one of the most challenging problems in materials science.

关键词： toughness carbide ceramics

Rational co.struction of heterointerfaces in biomass sugarcane-derived carbon for superior electromagnetic wave absorption

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第12期31卷 2749-2759页

作者： Shijie Zhang Di Lan Jiajun Zheng Ailing Feng Yaxing Pei Shichang Cai Suxuan Du Xingliang Chen Guanglei Wu Zirui Jia Key Laboratory of Clean Dyeing and Finishing Technology of Zhejiang Province Shaoxing Key Laboratory of High Performance Fibers&ProductsShaoxing UniversityShaoxing 312000China School of Materials Science and Engineering Hubei University of Automotive TechnologyShiyan 442002China School of Material Science and Engineering Henan University of TechnologyZhengzhou 450001China institute of Physics&Optoelectronics Technology Baoji University of Arts and SciencesBaoji 721016China zhengzhou research institute for abrasives and grinding Zhengzhou 450002China institute of Materials for Energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China

The pervasive adoption of 5th generation mobile co.munication technology propels electromagnetic wave(EW)absorbents to achieve high-level *** heterointerface co.struction is crucial to the improvement of absorption ***,a series of ultralight co.posites with rational heterointerfaces(co.ZnO@N-doped C/layer-stacked C,MSC)is fabricated by calcination with ration-al co.struction of sugarcane and co.n-zeolitic imidazolate framework(ZIF).The co.ponents and structures of as-prepared co.posites were investigated,and their electromagnetic parameters co.ld be adjusted by the co.tent of *** co.posites possess excellent EW absorption performance,especially *** optimal minimum reflection loss and effective absorption band of MSC-3 can reach−42 dB and 7.28 GHz at the thickness of only 1.6 mm with 20wt%filler *** excellent performance is attributed to the syner-gistic effect of dielectric loss stemming from the multiple heterointerfaces and magnetic loss induced by magnetic single *** sugar-cane-derived layer-stacked carbon has formed co.secutive co.ductive networks and has further dissipated the electromagnetic energy through multiple reflection and co.duction ***,the simulated radar cross section(RCS)technology manifests that MSC-3 possesses outstanding EW attenuation capacity under realistic far-field *** study provides a strategy for building efficient ab-sorbents based on biomass.

关键词： sugarcane-derived carbon heterointerfaces bimetallic metal-organic frameworks EW absorption radar cross section

Energy Band-gap Calculation of d-Ta_2O_5 Using sX-LDA and B3LYP Methods

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2015年第1期30卷 43-46页

作者：张光磊 GUO Xiaoyu LI Xuewen QIN Guoqiang FU Hua Hebei Provincial Key Laboratory of Traffic Engineering Materials Shijiazhuang Tiedao University School of Materials Science and Engineering Shijiazhuang Tiedao University zhengzhou research institute for abrasives & grinding co. Ltd.

The energy band-gap and related factors of tantalum pentoxide with hexagonal phase were investigated using hybrid functional B3LYP and sX-LDA methods. The results showed that both sX-LDA and B3LYP techniques reveal the indirect semico.ductor nature of δ-Ta2O5, whereas the obtained value of energy band-gap is much higher than previous theoretical reports but closer to the experimental data. The optical band- gap of δ-Ta2O5 is expected to originate from the O 2p→Ta 5d transition which may benefit from the d-s-p hybridization.

关键词： Ta2O5 B3LYP hexagonal phase sX-LDA band-gap

Dynamic Analysis of Geared Rotor System with Hybrid Uncertainties

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第5期 267-276页

作者： Wei Feng Luji Wu Yanxu Liu Baoguo Liu Zongyao Liu Kun Zhang Henan Key Laboratory of Super Hard abrasives and grinding Equipment Henan University of Technology Zheng Zhou research institute of Mechanical Engineering co. LTD School of Mechanical Engineering Tongji University

Current research on the dynamics and vibrations of geared rotor systems primarily focuses on deterministic models. However, uncertainties inevitably exist in the gear system, which cause uncertainties in system parameters and subsequently influence the accurate evaluation of system dynamic behavior. In this study, a dynamic model of a geared rotor system with mixed parameters and model uncertainties is proposed. Initially, the dynamic model of the geared rotor-bearing system with deterministic parameters is established using a finite element method. Subsequently, a nonparametric method is introduced to model the hybrid uncertainties in the dynamic model. Deviation co.fficients and dispersion parameters are used to reflect the levels of parameter and model uncertainty. For example, the study evaluates the effects of uncertain bearing and mesh stiffness on the vibration responses of a geared rotor system. The results demonstrate that the influence of uncertainty varies among different model types. Model uncertainties have a more significant than parametric uncertainties, whereas hybrid uncertainties increase the nonlinearities and co.plexities of the system's dynamic responses. These findings provide valuable insights into understanding the dynamic behavior of geared system with hybrid uncertainties.

关键词：

Dressing Mechanism and Evaluations of grinding Performance with Porous cBN grinding Wheels

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第5期 168-181页

作者： Jiahao Song Yu Yao Shandong Feng Biao Zhao Wenfeng Ding Guodong Xiao Qi Liu Dongdong Xu Yanjun Zhao Jianhui Zhu National Key Laboratory of Science and Technology on Helico.ter Transmission Nanjing University of Aeronautics and Astronautics China Aeronautical Radio Electronic research Institution Department of Mechanical Engineering University of Bath School of Mechanical Engineering Tongji University State Key Laboratory for High Performance Tools Zhengzhou Research Institute for Abrasives and Grinding Co.LTD

Cubic boron nitride(cBN) grinding wheels play a pivotal role in precision machining, serving as indispensable tools for achieving exceptional surface quality. Ensuring the sharpness of cBN grains and optimizing the grinding wheel's chip storage capacity are critical factors. This paper presents a study on the metal-bonded segments and single cBN grain samples using the vacuum sintering method. It investigates the impact of blasting parameters—specifically silico. carbide(SiC) abrasive size, blasting distance, and blasting time—on the erosive wear characteristics of both the metal bond and abrasive. The findings indicate that the abrasive size and blasting distance significantly affect the erosive wear performance of the metal bond. Following a co.prehensive analysis of the material removal rate of the metal bond and the erosive wear co.dition of cBN grains, optimal parameters for the working layer are determined: a blasting distance of 60 mm, a blasting time of 15 s, and SiC particle size of 100#. Furthermore,an advanced simulation model investigates the dressing process of abrasive blasting, revealing that the metal bond effectively inhibits crack propagation within cBN abrasive grains, thereby enhancing fracture toughness and impact resistance. Additionally, a co.parative analysis is co.ducted between the grinding performance of porous cBN grinding wheels and vitrified cBN grinding wheels. The results demonstrate that using porous cBN grinding wheels significantly reduces grinding force, temperature, and chip adhesion, thereby enhancing the surface quality of the workpiece.

关键词：