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Grindability Evaluation of Ultrasonic Assisted Grinding of Silicon Nitride Ceramic Using Minimum Quantity Lubrication Based SiO_(2)Nanofluid 被引量:2
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作者 Yusuf Suleiman Dambatta Changhe Li +8 位作者 Mohd Sayuti Ahmed A D Sarhan Min Yang Benkai Li Anxue Chu Mingzheng Liu Yanbin Zhang Zafar Said Zongming Zhou 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第2期115-136,共22页
Minimum quantity Lubrication(MQL)is a sustainable lubrication system that is famous in many machining systems.It involve the spray of an infinitesimal amount of mist-like lubricants during machining processes.The MQL ... Minimum quantity Lubrication(MQL)is a sustainable lubrication system that is famous in many machining systems.It involve the spray of an infinitesimal amount of mist-like lubricants during machining processes.The MQL system is affirmed to exhibit an excellent machining performance,and it is highly economical.The nanofluids are understood to exhibit excellent lubricity and heat evacuation capability,compared to pure oil-based MQL system.Studies have shown that the surface quality and amount of energy expended in the grinding operations can be reduced considerably due to the positive effect of these nanofluids.This work presents an experimental study on the tribological performance of SiO_(2)nanofluid during grinding of Si_(3)N_(4)ceramic.The effect different grinding modes and lubrication systems during the grinding operation was also analyzed.Different concentrations of the SiO_(2)nanofluid was manufactured using canola,corn and sunflower oils.The quantitative evaluation of the grinding process was done based on the amount of grinding forces,specific grinding energy,frictional coefficient,and surface integrity.It was found that the canola oil exhibits optimal lubrication performance compared to corn oil,sunflower oil,and traditional lubrication systems.Additionally,the introduction of ultrasonic vibrations with the SiO_(2)nanofluid in MQL system was found to reduce the specific grinding energy,normal grinding forces,tangential grinding forces,and surface roughness by 65%,57%,65%,and 18%respectively.Finally,regression analysis was used to obtain an optimum parameter combinations.The observations from this work will aid the smooth transition towards ecofriendly and sustainable machining of engineering ceramics. 展开更多
关键词 Minimum quantity lubrication(MQL) Ultrasonic assisted grinding(UAG) Eco-friendly lubricants NANOFLUID GRINDING ceramic
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Advances and challenges in direct additive manufacturing of dense ceramic oxides 被引量:1
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作者 Zhiqi Fan Qiyang Tan +1 位作者 Chengwei Kang Han Huang 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第5期59-94,共36页
Ceramic oxides,renowned for their exceptional combination of mechanical,thermal,and chemical properties,are indispensable in numerous crucial applications across diverse engineering fields.However,conventional manufac... Ceramic oxides,renowned for their exceptional combination of mechanical,thermal,and chemical properties,are indispensable in numerous crucial applications across diverse engineering fields.However,conventional manufacturing methods frequently grapple with limitations,such as challenges in shaping intricate geometries,extended processing durations,elevated porosity,and substantial shrinkage deformations.Direct additive manufacturing(dAM)technology stands out as a state-of-the-art solution for ceramic oxides production.It facilitates the one-step fabrication of high-performance,intricately designed components characterized by dense structures.Importantly,dAM eliminates the necessity for post-heat treatments,streamlining the manufacturing process and enhancing overall efficiency.This study undertakes a comprehensive review of recent developments in dAM for ceramic oxides,with a specific emphasis on the laser powder bed fusion and laser directed energy deposition techniques.A thorough investigation is conducted into the shaping quality,microstructure,and properties of diverse ceramic oxides produced through dAM.Critical examination is given to key aspects including feedstock preparation,laser-material coupling,formation and control of defects,in-situ monitoring and simulation.This paper concludes by outlining future trends and potential breakthrough directions,taking into account current gaps in this rapidly evolving field. 展开更多
关键词 ceramic oxides direct additive manufacturing microstructure DEFECTS mechanical properties
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New Strategy for Boosting Cathodic Performance of Protonic Ceramic Fuel Cells Through Incorporating a Superior Hydronation Second Phase 被引量:1
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作者 Chuan Zhou Xixi Wang +12 位作者 Dongliang Liu Meijuan Fei Jie Dai Daqin Guan Zhiwei Hu Linjuan Zhang Yu Wang Wei Wang Ryan O'Hayre San Ping Jiang Wei Zhou Meilin Liu Zongping Shao 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第4期83-92,共10页
For protonic ceramic fuel cells,it is key to develop material with high intrinsic activity for oxygen activation and bulk proton conductivity enabling water formation at entire electrode surface.However,a higher water... For protonic ceramic fuel cells,it is key to develop material with high intrinsic activity for oxygen activation and bulk proton conductivity enabling water formation at entire electrode surface.However,a higher water content which benefitting for the increasing proton conductivity will not only dilute the oxygen in the gas,but also suppress the O_(2)adsorption on the electrode surface.Herein,a new electrode design concept is proposed,that may overcome this dilemma.By introducing a second phase with high-hydrating capability into a conventional cobalt-free perovskite to form a unique nanocomposite electrode,high proton conductivity/concentration can be reached at low water content in atmosphere.In addition,the hydronation creates additional fast proton transport channel along the two-phase interface.As a result,high protonic conductivity is reached,leading to a new breakthrough in performance for proton ceramic fuel cells and electrolysis cells devices among available air electrodes. 展开更多
关键词 CATHODE high-hydrating capability proton conductivity protonic ceramic fuel cells
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Robust and Tunable Ferroelectricity in Ba/Co Codoped (K_(0.5)Na_(0.5))NbO_(3) Ceramics
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作者 刘佳讯 查节林 +5 位作者 杨玉龙 吕笑梅 胡雪莉 阎朔 吴子敬 黄凤珍 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第7期152-160,共9页
The 0.98(K_(0.5)Na_(0.5))NbO_(3)-0.02Ba(Nb_(0.5)Co_(0.5))O_(3-δ) ceramics with doped Ba^(2+) and Co^(2+) ions are fabricated,and the impacts of the thermal process are studied.Compared with the rapidly cooled (RC) sa... The 0.98(K_(0.5)Na_(0.5))NbO_(3)-0.02Ba(Nb_(0.5)Co_(0.5))O_(3-δ) ceramics with doped Ba^(2+) and Co^(2+) ions are fabricated,and the impacts of the thermal process are studied.Compared with the rapidly cooled (RC) sample,the slowly cooled (SC) sample possesses superior dielectric and ferroelectric properties,and an 11 K higher ferroelectricparaelectric phase transition temperature,which can be attributed to the structural characteristics such as the grain size and the degree of anisotropy.Heat treatment can reversibly modulate the content of the oxygen vacancies,and in turn the ferroelectric hysteresis loops of the samples.Finally,robust and tunable ferroelectric property is achieved in SC samples with good structural integrity. 展开更多
关键词 ceramicS FERROELECTRIC treatment
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Synthesis of SiOC@C ceramic nanospheres with tunable electromagnetic wave absorption performance
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作者 Junjie Qian Dandan Ma +5 位作者 Xiaoling Zhou Huoming Liao Qingliang Shan Shaohua Wang Yongqing Wang Xiaojun Zeng 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2024年第9期1394-1408,共15页
SiOC-based ceramics are considered promising electromagnetic wave-absorbing materials because of their lightweight,high-temperature resistance,and heat insulation properties.Herein,SiOC@C ceramic nanospheres were prep... SiOC-based ceramics are considered promising electromagnetic wave-absorbing materials because of their lightweight,high-temperature resistance,and heat insulation properties.Herein,SiOC@C ceramic nanospheres were prepared using a liquid-phase method combined with a polymer-derived ceramic(PDC)method,followed by heat treatment in N_(2) and Ar atmospheres at different temperatures.The morphology,microstructure,phase composition,and electromagnetic wave absorption performance of the SiOC@C ceramic nanospheres were investigated in detail.The SiOC@C ceramic nanospheres obtained in the Ar atmosphere showed a minimum reflection loss(RL_(min))of−67.03 dB,whereas the SiOC@C ceramic nanospheres obtained in the N_(2) atmosphere exhibited an RLmin value of−63.76 dB.The outstanding electromagnetic wave absorption performance of the SiOC@C ceramic nanospheres was attributed to the synergistic effect between conductive loss,interfacial/defect polarization loss,multiple reflections,and scattering.Therefore,this research provides valuable insights into the design and fabrication of SiOC ceramic-based electromagnetic wave absorbers. 展开更多
关键词 SiOC ceramic nanospheres electromagnetic wave absorption performance polymer-derived ceramics(PDCs) free carbon
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Advanced research on the preparation and application of carbide ceramic fibers
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作者 Zhongqian Zhao Wei Liao +3 位作者 Jing Chen Jian Jiao Cuilan Wu Yanzi Gou 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2024年第9期1291-1336,共46页
Carbide ceramic fibers are of significant importance for application in the high-tech areas of advanced aircraft engines,aerospace vehicles,and the nuclear industry due to their excellent properties,such as high tensi... Carbide ceramic fibers are of significant importance for application in the high-tech areas of advanced aircraft engines,aerospace vehicles,and the nuclear industry due to their excellent properties,such as high tensile strength and elastic modulus,excellent high-temperature resistance,and oxidation resistance.This paper reviews the preparation and application of different carbide ceramic fibers,including SiC fibers and transition metal carbide(e.g.,ZrC,HfC,and TaC)ceramic fibers.The preparation methods of carbide ceramic fibers are discussed in terms of different fiber diameters,represented by SiC fibers with variable weaving properties and functions due to their differences in diameter.Subsequently,the application of carbide ceramic fibers as high-temperature-resistant structural materials,catalyst carriers,sensors,and supercapacitors are summarized,and strategies for the future development of carbide ceramic fibers are proposed.This review aims to help researchers enhance their understanding of the preparation and utilization of carbide ceramic micro/nanofibers,advancing the development of high-performance carbide ceramic fibers. 展开更多
关键词 carbide ceramic fibers SiC fibers boron carbide(B_(4)C)fibers ultra-high temperature ceramics SiC ceramic fiber-reinforced SiC(SiCf/SiC)composites
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Structural and Luminescent Properties of Mg_(0.25-x)Al_(2.57)O_(3.79)N_(0.21):xMn^(2+)Green-Emitting Transparent Ceramic Phosphor
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作者 郝留成 MIAO Xiaojun +4 位作者 LI Kai ZHONG Jianying 涂兵田 YANG Zhangfu 王皓 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第3期533-540,共8页
A series of spinel-type Mg_(0.25-x)Al_(2.57)O_(3.79)N_(0.21):xMn^(2+)(MgAlON:xMn^(2+))phosphors were synthesized by the solid-state reaction route.The transparent ceramic phosphors were fabricated by pressureless sint... A series of spinel-type Mg_(0.25-x)Al_(2.57)O_(3.79)N_(0.21):xMn^(2+)(MgAlON:xMn^(2+))phosphors were synthesized by the solid-state reaction route.The transparent ceramic phosphors were fabricated by pressureless sintering followed by hot-isostatic pressing(HIP).The crystal structure,luminescence and mechanical properties of the samples were systematically investigated.The transparent ceramic phosphors with tetrahedrally coordinated Mn^(2+)show strong green emission centered around 515 nm under blue light excitation.As the Mn^(2+)concentration increases,the crystal lattice expands slightly,resulting in a variation of crystal field and a slight red-shift of green emission peak.Six weak absorption peaks in the transmittance spectra originate from the spin-forbidden ^(4)T_(1)(^(4)G)→^(6)A_(1) transition of Mn^(2+).The decay time was found to decrease from 5.66 to 5.16 ms with the Mn^(2+)concentration.The present study contributes to the systematic understanding of crystal structure and properties of MgAlON:xMn^(2+)green-emitting transparent ceramic phosphor which has a potential application in high-power light-emitting diodes. 展开更多
关键词 transparent ceramic phosphor green emission MGALON PHOTOLUMINESCENCE
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Realizing large strain at low electric field in Pb(Zr,Ti)O_(3)-based piezoelectric ceramics via engineering lattice distortion and domain structure
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作者 Denghui Jiang Feng Luo +6 位作者 Kao Pei Hongyu Yang Linzhuang Xing Yangxi Yan Mo Zhao Zhimin Li Yue Hao 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2024年第9期1409-1421,共13页
Pb(Zr,Ti)O_(3)-based ceramics are the mainstream materials for commercial multilayer piezoelectric ceramic actuators,but to date,large strains at low electric fields have not been well solved.Herein,0.95Pb(Zr_(0.56)Ti... Pb(Zr,Ti)O_(3)-based ceramics are the mainstream materials for commercial multilayer piezoelectric ceramic actuators,but to date,large strains at low electric fields have not been well solved.Herein,0.95Pb(Zr_(0.56)Ti_(0.44))O_(3)–0.05(Bi_(0.5)Na_(0.5))TiO_(3–x)BaZrO_(3)(PZT–BNT–xBZ)ceramics with efficient ferroelectric domain wall motion were designed and realized by reducing lattice distortion and changing the domain structure.It is found that the introduction of BaZrO_(3)(BZ)weakens the tetragonal phase distortion of PZT,contributing to a reduction in the mechanical stress that impedes the migration of domain walls.Moreover,the domain structures could be modified by adjusting the BZ content,where short and broad striped domains are constructed with high amplitude characteristics to enhance the domain wall motion.A large strain of 0.39%is accordingly achieved at an electric field as low as 40 kV/cm for the sample with x=0.03,accompanied by excellent temperature stability over the temperature range of 30–210℃.This study delves into the synergistic effects of reducing lattice distortion and changing domain structure on domain wall motion and provides an effective strategy to improve the strain of PZT-based piezoelectric ceramics. 展开更多
关键词 PZT ceramic STRAIN ferroelectric domain lattice distortion
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Preparation and Photostriction Properties of BiFeO_(3)-BaTiO_(3)Ceramics
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作者 ZHENG Zewei ZHANG Liqiang +3 位作者 CHEN Chen CAO Minghe YI Zhiguo LIU Hanxing 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第5期1079-1086,共8页
Under illumination by 405,520 and 655 nm monochromatic visible light(light intensity of 30 kW/m^(2)),large photostriction(ΔL/L)of 0.19%,0.13%and 0.26%for 67BiFeO_(3)-33BaTiO_(3)(67BF-33BT)lead-free ferroelectric cera... Under illumination by 405,520 and 655 nm monochromatic visible light(light intensity of 30 kW/m^(2)),large photostriction(ΔL/L)of 0.19%,0.13%and 0.26%for 67BiFeO_(3)-33BaTiO_(3)(67BF-33BT)lead-free ferroelectric ceramics are obtained,respectively.By studying the ferroelectric and photoelectric properties in conjunction with in situ Raman spectroscopy,it is found that the photostrictive effect of 67BF-33BT is not caused by the electrical strain induced by abnormal photovoltaic voltage,but related to the optical induced oxygen octahedral distortion.The 67BF-33BT lead-free ferroelectric material with excellent photostrictive response in the visible light region is expected to play an important role in the field of optical drive electromechanical devices. 展开更多
关键词 ferroelectric ceramics photostrictive effect visible light response
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Manipulating Zr/Ti ratio based on phase diagram for large electrocaloric effects with multiple target operation temperatures in PLZT ceramics
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作者 Junjie Li Ruowei Yin +5 位作者 Zhe Xiong Yizheng Bao Xing Zhang Wenjuan Wu Lezhong Li Yang Bai 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2024年第9期1422-1431,共10页
Ferroelectric phase transition has been identified as a promising avenue for designing high-performanceelectrocaloric materials for zero-emission and solid-state refrigeration. However, extensive research has been lim... Ferroelectric phase transition has been identified as a promising avenue for designing high-performanceelectrocaloric materials for zero-emission and solid-state refrigeration. However, extensive research has been limited todeveloping ferroelectric materials with large electrocaloric effects near room temperature, preventing them from meetingdiverse refrigeration requirements. In this study, by leveraging the room-temperature phase diagram of the (PbLa)(ZrTi)O_(3)solution, we prepared a series of Pb_(0.775)La_(0.15)Zr_(x)Ti_(1−x)O_(3) bulk ceramics spanning the ferroelectric and relaxor ferroelectricphase regions. This enabled the attainment of various phase transition features and temperatures. Finally, largeelectrocaloric effects, coupled with adjustable operation temperatures ranging from 150 to −45℃, are successfullyachieved through manipulation of the Zr/Ti ratio. This comprehensive range of operation temperatures effectively addressesdiverse refrigeration application requirements, ranging from industrial equipment to freezer cabinets. This work not onlyunderscores the expansion of the electrocaloric refrigeration application domain but also proposes a material designstrategy tailored to meet these evolving demands. 展开更多
关键词 electrocaloric effect phase transition phase diagram ferroelectric ceramics
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Microstructure Characteristics and Possible Phase Evolution of the Coal Gangue-Steel Slag Ceramics Prepared by the Solid-State Reaction Methods
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作者 刘文洁 WANG Yang +1 位作者 LI Jingtao 李宝让 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第4期921-930,共10页
Industrial wastes such as steel slag and coal gangue etc.were chosen as raw materials for preparing ceramic via the conventional solid-state reaction method.With steel slag and coal gangue mixed in various mass ratios... Industrial wastes such as steel slag and coal gangue etc.were chosen as raw materials for preparing ceramic via the conventional solid-state reaction method.With steel slag and coal gangue mixed in various mass ratios,from 100%steel slag to 100%coal gangue at 10%intervals,microstructure and possible phase evolution of the coal gangue-steel slag ceramics were investigated using X-ray powder diffraction,scanning electron microscopy,mercury intrusion porosimetry and Archimedes boiling method.The experimental results suggest that the phase compositions of the as-prepared ceramics could be altered with the increased amount of coal gangue in the ceramics.The anorthite-diopside eutectic can be formed in the ceramics with the mass ratios of steel slag to coal gangue arranged from 8:2 to 2:8,which was responsible for the melting of the steel slag-coal gangue ceramics at relatively high temperature.Further investigations on the microstructure suggested that the addition of the proper amount of steel slag in ceramic compositions was conducive to the pore formation and further contributed to an increment in porosity. 展开更多
关键词 steel slag-coal gangue ceramics SYNTHESIS phase evolution microstructure characteristics
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Rational Design of Ruddlesden-Popper Perovskite Ferrites as Air Electrode for Highly Active and Durable Reversible Protonic Ceramic Cells
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作者 Na Yu Idris Temitope Bello +4 位作者 Xi Chen Tong Liu Zheng Li Yufei Song Meng Ni 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第9期308-324,共17页
Reversible protonic ceramic cells(RePCCs)hold promise for efficient energy storage,but their practicality is hindered by a lack of high-performance air electrode materials.Ruddlesden-Popper perovskite Sr_(3)Fe_(2)O_(7... Reversible protonic ceramic cells(RePCCs)hold promise for efficient energy storage,but their practicality is hindered by a lack of high-performance air electrode materials.Ruddlesden-Popper perovskite Sr_(3)Fe_(2)O_(7−δ)(SF)exhibits superior proton uptake and rapid ionic conduction,boosting activity.However,excessive proton uptake during RePCC operation degrades SF’s crystal structure,impacting durability.This study introduces a novel A/B-sites co-substitution strategy for modifying air electrodes,incorporating Sr-deficiency and Nb-substitution to create Sr_(2.8)Fe_(1.8)Nb_(0.2)O_(7−δ)(D-SFN).Nb stabilizes SF’s crystal,curbing excessive phase formation,and Sr-deficiency boosts oxygen vacancy concentration,optimizing oxygen transport.The D-SFN electrode demonstrates outstanding activity and durability,achieving a peak power density of 596 mW cm^(−2)in fuel cell mode and a current density of−1.19 A cm^(−2)in electrolysis mode at 1.3 V,650℃,with excellent cycling durability.This approach holds the potential for advancing robust and efficient air electrodes in RePCCs for renewable energy storage. 展开更多
关键词 Reversible protonic ceramic cells Air electrode Ruddlesden-Popper perovskite HYDRATION Oxygen reduction reaction
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Harvesting Energy Via Water Movement and Surface Ionics in Microfibrous Ceramic Wools
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作者 Manpreet Kaur Avinash Alagumalai +3 位作者 Omid Mahian Sameh M.Osman Tadaaki Nagao Zhonglin Wang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第6期332-341,共10页
Due to the push for carbon neutrality in various human activities,the development of methods for producing electricity without relying on chemical reaction processes or heat sources has become highly significant.Also,... Due to the push for carbon neutrality in various human activities,the development of methods for producing electricity without relying on chemical reaction processes or heat sources has become highly significant.Also,the challenge lies in achieving microwatt-scale outputs due to the inherent conductivity of the materials and diverting electric currents.To address this challenge,our research has concentrated on utilizing nonconductive mediums for water-based low-cost microfibrous ceramic wools in conjunction with a NaCl aqueous solution for power generation.The main source of electricity originates from the directed movement of water molecules and surface ions through densely packed microfibrous ceramic wools due to the effect of dynamic electric double layer.This occurrence bears resemblance to the natural water transpiration in plants,thereby presenting a fresh and straightforward approach for producing electricity in an ecofriendly manner.The generator module demonstrated in this study,measuring 12×6 cm^(2),exhibited a noteworthy open-circuit voltage of 0.35 V,coupled with a short-circuit current of 0.51 mA.Such low-cost ceramic wools are suitable for ubiquitous,permanent energy sources and hold potential for use as self-powered sensors and systems,eliminating the requirement for external energy sources such as sunlight or heat. 展开更多
关键词 ceramic microfibers energy harvesting power generation self-powered systems water evaporation
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A critical review of direct laser additive manufacturing ceramics
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作者 Dake Zhao Guijun Bi +4 位作者 Jie Chen WaiMeng Quach Ran Feng Antti Salminen Fangyong Niu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第12期2607-2626,共20页
The urgent need for integrated molding and sintering across various industries has inspired the development of additive manu-facturing(AM)ceramics.Among the different AM technologies,direct laser additive manufacturin... The urgent need for integrated molding and sintering across various industries has inspired the development of additive manu-facturing(AM)ceramics.Among the different AM technologies,direct laser additive manufacturing(DLAM)stands out as a group of highly promising technology for flexibly manufacturing ceramics without molds and adhesives in a single step.Over the last decade,sig-nificant and encouraging progress has been accomplished in DLAM of high-performance ceramics,including Al_(2)O_(3),ZrO_(2),Al_(2)O_(3)/ZrO_(2),SiC,and others.However,high-performance ceramics fabricated by DLAM face challenges such as formation of pores and cracks and resultant low mechanical properties,hindering their practical application in high-end equipment.Further improvements are necessary be-fore they can be widely adopted.Methods such as field-assisted techniques and post-processing can be employed to address these chal-lenges,but a more systematic review is needed.This work aims to critically review the advancements in direct selective laser sintering/melting(SLS/SLM)and laser directed energy deposition(LDED)for various ceramic material systems.Additionally,it provides an overview of the current challenges,future research opportunities,and potential applications associated with DLAM of high-perform-ance ceramics. 展开更多
关键词 3D printing laser additive manufacturing ceramicS quality MICROSTRUCTURE mechanical properties
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High-performance grinding of ceramic matrix composites
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作者 Jingfei Yin Jiuhua Xu Honghua Su 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2024年第3期45-55,共11页
Ceramic matrix composites(CMCs)are highly promising materials for the next generation of aero-engines.However,machining of CMCs suffers from low efficiency and poor surfacefinish,which presents an obstacle to their wide... Ceramic matrix composites(CMCs)are highly promising materials for the next generation of aero-engines.However,machining of CMCs suffers from low efficiency and poor surfacefinish,which presents an obstacle to their wider application.To overcome these problems,this study investigates high-efficiency deep grinding of CMCs,focusing on the effects of grinding depth.The results show that both the sur-face roughness and the depth of subsurface damage(SSD)are insensitive to grinding depth.The material removal rate can be increased sixfold by increasing the grinding depth,while the surface roughness and SSD depth increase by only about 10%.Moreover,it is found that the behavior of material removal is strongly dependent on grinding depth.As the grinding depth is increased,fibers are removed in smaller sizes,with thefiber length in chips being reduced by about 34%.However,too large a grinding depth will result in blockage by chip powder,which leads to a dramatic increase in the ratio of tangential to normal grinding forces.This study demonstrates that increasing the depth of cut is an effective approach to improve the machining efficiency of CMCs,while maintaining a good surfacefin-ish.It provides the basis for the further development of high-performance grinding methods for CMCs,which should facilitate their wider application. 展开更多
关键词 ceramic matrix composite GRINDING Surfacefinish Subsurface damage Fiber breakage
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Microstructure and Oxidation Behavior of ZrB_(2)-SiC Ceramics Fabricated by Tape Casting and Reactive Melt Infiltration
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作者 TAN Min CHEN Xiaowu +5 位作者 YANG Jinshan ZHANG Xiangyu KAN Yanmei ZHOU Haijun XUE Yudong DONG Shaoming 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2024年第8期955-964,共10页
ZrB_(2)-based ceramics typically necessitate high temperature and pressure for sintering,whereas ZrB_(2)-SiC ceramics can be fabricated at 1500℃using the process of reactive melt infiltration with Si.In comparison to... ZrB_(2)-based ceramics typically necessitate high temperature and pressure for sintering,whereas ZrB_(2)-SiC ceramics can be fabricated at 1500℃using the process of reactive melt infiltration with Si.In comparison to the conventional preparation method,reactive synthesis allows for the more facile production of ultra-high temperature ceramics with fine particle size and homogeneous composition.In this work,ZrSi_(2),B4C,and C were used as raw materials to prepare ZrB_(2)-SiC via combination of tape casting and reactive melt infiltration herein referred to as ZBC ceramics.Control sample of ZrB_(2)-SiC was also prepared using ZrB_(2) and SiC as raw materials through an identical process designated as ZS ceramics.Microscopic analysis of both ceramic groups revealed smaller and more uniformly distributed particles of the ZrB_(2) phase in ZBC ceramics compared to the larger particles in ZS ceramics.Both sets of ceramics underwent cyclic oxidation testing in the air at 1600℃for a cumulative duration of 5 cycles,each cycle lasting 2 h.Analysis of the oxidation behavior showed that both ZBC ceramics and ZS ceramics developed a glassy SiO_(2)-ZrO_(2) oxide layer on their surfaces during the oxidation.This layer severed as a barrier against oxygen.In ZBC ceramics,ZrO_(2) is finely distributed in SiO_(2),whereas in ZS ceramics,larger ZrO_(2) particles coexist with glassy SiO_(2).The surface oxide layer of ZBC ceramics maintains a dense structure because the well-dispersed ZrO_(2) increases the viscosity of glassy SiO_(2),preventing its crystallization during the cooling.Conversely,some SiO_(2) in the oxide layer of ZS ceramics may crystallize and form a eutectic with ZrO_(2),leading to the formation of ZrSiO_(4).This leads to cracking of the oxide layer due to differences in thermal expansion coefficients,weakening its barrier effect.An analysis of the oxidation resistance shows that ZBC ceramics exhibit less increase in oxide layer thickness and mass compared to ZS ceramics,suggesting superior oxidation resistance of ZBC ceramics. 展开更多
关键词 ultra-high temperature ceramic ZRB2-SIC oxidation behavior reactive melt infiltration
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Low-firing and temperature stability regulation of tri-rutile MgTa_(2)O_(6)microwave dielectric ceramics
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作者 Chengzhi Xu Hongyu Yang +5 位作者 Hongcheng Yang Linzhuang Xing Yuan Wang Zhimin Li Enzhu Li Guorui Zhao 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第8期1935-1943,共9页
A glass frit containing Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)component was used to explore the low-temperature sintering behaviors and microwave dielectric characteristics of tri-rutile MgTa_(2)O_(6)ceramics in this stud... A glass frit containing Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)component was used to explore the low-temperature sintering behaviors and microwave dielectric characteristics of tri-rutile MgTa_(2)O_(6)ceramics in this study.The good low-firing effects are presented due to the high matching relevance between Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass and MgTa_(2)O_(6)ceramics.The pure tri-rutile MgTa_(2)O_(6)structure remains unchanged,and high sintering compactness can also be achieved at 1150℃.We found that the Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass not only greatly improves the low-temperature sintering characteristics of MgTa_(2)O_(6)ceramics but also maintains a high(quality factor(Q)×resonance frequency(f))value while still improving the temperature stability.Typically,great microwave dielectric characteristics when added with 2wt%Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass can be achieved at 1150℃:dielectric constant,ε_(r)=26.1;Q×f=34267 GHz;temperature coefficient of resonance frequency,τ_(f)=-8.7×10^(-6)/℃. 展开更多
关键词 MgTa_(2)O_(6) ceramic microwave dielectric characteristics glass
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Failure pattern in ceramic metallic target under ballistic impact
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作者 M.A.Iqbal M.K.Khan 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第10期173-190,共18页
The ballistic resistance and failure pattern of a bi-layer alumina 99.5%-aluminium alloy 1100-H12 target against steel 4340 ogival nosed projectile has been explored in the present experimental cum numerical study.In ... The ballistic resistance and failure pattern of a bi-layer alumina 99.5%-aluminium alloy 1100-H12 target against steel 4340 ogival nosed projectile has been explored in the present experimental cum numerical study.In the experimental investigation,damage induced in the ceramic layer has been quantified in terms of number of cracks developed and failure zone dimensions.The resultant damage in the backing layer has been studied with variation in the bulge and perforation hole in the backing layer with the varying incidence velocity.The discussion of the experimental results has been further followed by three dimensional finite element computations using ABAQUS/Explicit finite code to investigate the behaviour of different types of bi-layer targets under multi-hit projectile impact.The JH-2 constitutive model has been used to reproduce the behaviour of alumina 99.5%and JC constitutive model has been used for steel 4340 and aluminium alloy 1100-H12.The total energy dissipation has been noted to be of lesser magnitude in case of sub-sequential impact in comparison to simultaneous impact of two projectiles.The distance between the impact points of two projectiles also effected the ballistic resistance of bi-layer target.The ballistic resistance of single tile ceramic front layer and four tile ceramic of equivalent area found to be dependent upon the boundary conditions provided to the target. 展开更多
关键词 Ballistic resistance Bi-layer target ceramic metal armour Multi-hit impact Finite element modelling
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Effect of Sc substitution on the phase composition,microstructure,and properties of(Tb_(1−x)Sc_(x))_(3)(Al_(1−y)Sc_(y))_(2)Al_(3)O_(12) transparent ceramics
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作者 Lixuan Zhang Chen Hu +5 位作者 Xiao Li Zhenzhen Zhou Tingsong Li Yiyang Liu Lexiang Wu Jiang Li 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2024年第9期1442-1452,共11页
Terbium aluminum garnet(Tb_(3)Al_(5)O_(12);TAG)ceramics are among the most promising magneto–optical materials owing to their outstanding comprehensive performance.Many works have focused on improving the optical qua... Terbium aluminum garnet(Tb_(3)Al_(5)O_(12);TAG)ceramics are among the most promising magneto–optical materials owing to their outstanding comprehensive performance.Many works have focused on improving the optical quality of TAG ceramics.A key point for improving optical quality is ensuring the accuracy of the stoichiometric ratio and avoiding secondary phases.In this work,0,2,4,or 6 wt%Sc2O3 was added to the TAG ceramics to increase the solid solubility.The effects of Sc substitution on the crystal structure,sintering process,microstructure,optical transmittance,and magneto–optical properties of(Tb_(1−x)Sc_(x))_(3)(Al_(1−y)Sc_(y))_(2)Al_(3)O_(12)(TSAG)ceramics are studied in detail.4 wt%Sc2O3:TAG ceramics with an in-line transmittance of 82.2%at 1064 nm and 81.2%at 633 nm were successfully fabricated,and the Verdet constant was 164.4 rad·T^(−1)·m^(−1) at 633 nm.Anti-site defects(ADs)and Sc replacement in TAG are further studied via first-principles calculations to determine the working mechanism of Sc.Both the experimental and calculation results show that the introduction of Sc can effectively increase the solid solubility of TAG ceramics,suppress secondary phases,and hence improve the optical transmittance. 展开更多
关键词 terbium aluminum garnet ceramics magneto-optical materials microstructures anti-site defects(ADs) firstprinciples calculations
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High-temperature BaTiO_(3) -based ceramic capacitors by entropy engineering design
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作者 Yan Song Min Zhang +4 位作者 Shun Lan Bingbing Yang Yiqian Liu Ce-Wen Nan Yuan-Hua Lin 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2024年第9期1498-1504,共7页
High-performance BaTiO_(3)(BTO)-based dielectric ceramics have great potential for high-power energy storagedevices. However, its poor temperature reliability and stability due to its low Curie temperature impedes the... High-performance BaTiO_(3)(BTO)-based dielectric ceramics have great potential for high-power energy storagedevices. However, its poor temperature reliability and stability due to its low Curie temperature impedes the development ofmost electronic applications. Herein, a series of BTO-based ceramics are designed and prepared on the basis of entropyengineering. Owing to the incorporation of Bi(Mg_(0.5)Ti_(0.5))O_(3), relaxation behavior and low dielectric loss at high temperatureshave been achieved. Moreover, the high-entropy strategy also promotes lattice distortion, grain refinement and excellentresistance, which together increase the breakdown field strength. These simultaneous effects result in outstanding energystorage performance, ultimately achieving stable energy density (U_(e)) of 5.76 J·cm^(−3) and efficiency ( η) of 89%. Mostimportantly, the outstanding temperature stability makes high-entropy BTO-based ceramics realize a significant energystorage density of 4.90 0.14 J·cm^(−3) with the efficiency above 89%, spanning a wide temperature range of 25–250 ℃, aswell as cycling reliability with negligible performance deterioration after 3 105 cycles at 300 kV∙cm^(−1) and 200 ℃. Thisresearch presents an effective method for designing temperature-stable and reliable dielectrics with comprehensive energystorage performance. 展开更多
关键词 BaTiO_(3)-based ceramics high-entropy effects high-temperature energy storage cycling reliability
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