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Sintering behavior, microstructure and properties of TiC-FeCr hard alloy

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Journal of University of Science and technology Beijing 2007年第1期14卷 89-93页

作者： Farid Akhtar Shiju Guo Jawid Askari Jianjun Tian Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China Department of Metallurgical and Malerials Engineering University of Engineering and Technology Lahore Pakistan

TiC based cermets were produced with FeCr, as a binder, by conventional P/M （powder metallurgy） to near 〉97% of the theoretical density. Sintering temperature significantly affects the mechanical properties of the composite. The sintering temperature of 〉1360℃ caused severe chemical reaction between TiC particles and the binder phase. In the TiC-FeCr cermets, the mechanical properties did not vary linearly with the carbide content. Optimum mechanical properties were found in the composite containing 57wt% TiC reinforcement, when sintered at 1360℃ for 1 h. Use of carbon as an additive enhanced the mechanical properties of the composites. Cermets containing carbon as an additive with 49wt% TiC exhibited attractive mechanical properties. The microstructure of the developed composite contained less or no debonding, representing good wettabifity of the binder with TiC particles. Homogeneous distribution of the TiC particles ensured the presence of isotropic mechanical properties and homogeneous distribution of stresses in the composite. Preliminary experiments for evaluation of the oxidation resistance of FeCr bonded TiC cermets indicate that they are more resistant than WC-Co hardmetals.

关键词： powder technology hard alloy sintering reinforcement mechanical property

Amination of biochar surface from watermelon peel for toxic chromium removal enhancement

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Chinese Journal of Chemical Engineering 2021年第8期34卷 199-222页

作者： Mohamed A.El-Nemr Ibrahim M.A.Ismail Nabil M.Abdelmonem Ahmed El Nemr Safaa Ragab Department of Chemical Engineering Faculty of EngineeringCairo UniversityGizaEgypt Renewable Energy Program Zewail City of Science and TechnologyEgypt Environmental Division National Institute of Oceanography and FisheriesKayet BeyEl-AnfoushyAlexandriaEgypt

Watermelon peel residues were used to produce a new biochar by dehydration *** new biochar has undergone two methods of chemical modification and the effect of this chemical modification on its ability to adsorb Cr(VI)ions from aqueous solution has been *** biochars,Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA,were made from watermelon peel via dehydration with 50%sulfuric acid to give Melon-B followed by oxidation with ozone and amination using ammonium hydroxide to give Melon-BO-NH_(2) or Triethylenetetramine(TETA)to give *** prepared biochars were characterized by BET,BJH,SEM,FT-IR,TGA,DSC and EDAX *** highest removal percentage of Cr(VI)ions was 69%for Melon-B,98%for Melon-BO-NH_(2) and 99%for Melon-BO-TETA biochars of 100 mg·L^(−1) Cr(VI)ions initial concentration and 1.0 g·L^(−1) adsorbents *** unmodified biochar(Melon-B)and modified biochars(Melon-BO-NH_(2) and Melon-BO-TETA)had maximum adsorption capacities(Q_(m))of 72.46,123.46,and 333.33 mg·g^(−1),*** amination of biochar reduced the pore size of modified biochar,whereas the surface area was *** obtained data of isotherm models were tested using different error function *** Freundlich,Tempkin and Langmuir isotherm models were best fitted to the experimental data of Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA,*** adsorption rate was primarily controlled by pseudo-second–order rate ***,the functional groups interactions are important for adsorption mechanisms and expected to control the adsorption *** adsorption for the Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA could be explained for acid–base interaction and hydrogen bonding interaction.

关键词： Waste treatment powder technology Citrullus lanatus Hexavalent chromium Biochar amination Adsorption

Nanostructured yttrium aluminum garnet powders synthesized by co-precipitation method using tetraethylenepentamine

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Journal of Rare Earths 2009年第6期27卷 967-970页

作者：李先学王文菊 Department of Environment & Life Science Putian University Beijing Center for Crystal Research and Development Technical Institute of Physics and ChemistryChinese Academy of Sciences Financial Division Putian University

Tetraethylenepentamine(C8H23N5,TEPA) has been used as a novel precipitant to synthesize yttrium aluminum garnet(Y3Al5O12,YAG) precursor from a mixed solution of aluminum and yttrium nitrates via a normal-strike co-precipitation method without controlling the pH value during precipitation *** original precursor was analyzed by thermogravimetry/differential scanning calorimetry(TG/DSC).The evolution of phase composition and micro-structure of the as-synthesized YAG powders were characterized by X-ray ...

关键词： yttrium aluminum garnet powder technology co-precipitation ceramics rare earths

A Cost-Effective Co-precipitation Method for Synthesizing Indium Tin Oxide Nanoparticles without Chlorine Contamination

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Journal of Materials Science & technology 2010年第11期26卷 1037-1040页

作者： Haiwen Wang Xiujuan Xu Jianrong Zhang Chunzhong Li Department of Chemistry Key Laboratory for Advanced Materials of Ministry of Education East China University of Science and Technology Shanghai 200237 China Key Laboratory for Ultrafine Materials of Ministry of Education East China University of Science and Technology Shanghai 200237 China

Indium tin oxide （ITO） nanoparticles with crystallite size of 12.6 nm and specific surface area of 45.7 m 2 ·g-1 were synthesized by co-precipitation *** indium solution was obtained by dissolving metal indium in *** tin solution was obtained by dissolving metal tin in HNO3 and followed by stabilizing with citric *** free of chlorine ions in the synthesis process brought several advantages：shortening the synthesis time,decreasing the particle agglomeration,decreasing the chlorine content in the ITO nanoparticles and improving the particle *** is the first time to report the synthesis of ITO nanoparticles free from chlorine contamination without using the expensive metal alkoxides as starting materials.

关键词： Nanomaterials powder technology Indium tin oxide Coprecipitation method

Synthesis methods and powder quality of titanium monocarbide

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Chinese Journal of Chemical Engineering 2024年第8期72卷 10-18页

作者： Maoqiao Xiang Wenjun Ding Qinghua Dong Qingshan Zhu State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of the Chinese Academy of SciencesBeijing 100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing 100190China

Titanium monocarbide(TiC),which is the most stable titanium-based carbide,has attracted considerable interest in the fields of energy,catalysis,and structural materials due to its excellent *** of high-quality TiC powders with low cost and high efficiency is crucial for industrial applications;however major challenges face its ***,the methods for synthesizing TiC powders based on a reaction system are *** analysis is focused on the underlying mechanisms by which synthesis methods affect the quality of ***,strategies for improving the synthesis of highquality powders are analyzed from the perspective of enhancing heat and mass transfer ***,the critical issues,challenges,and development trends of the synthesis technology and application of high-quality TiC powder are discussed.

关键词： Titanium carbide Synthesis methods Reaction engineering Reaction kinetics powder technology

Spray pyrolysis synthesis of nickel-rich layered cathodes LiNi_(1-2x)Co_xMn_xO_2(x = 0.075, 0.05, 0.025) for lithium-ion batteries

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Journal of Energy Chemistry 2018年第2期27卷 447-450页

作者： Yan Li Xinhai Li Zhixing Wang Huajun Guo Jiexi Wang School of Metallurgy and Environment Central South University

In this study we report a series of nickel-rich layered cathodes LiNi1-2xCoxMnxO2（x = 0.075, 0.05,0.025） prepared from chlorides solution via ultrasonic spray pyrolysis. SEM images illustrate that the samples are submicron-sized particles and the particle sizes increase with the increase of Ni ***0.85Co0.075Mn0.075O2 delivers a discharge capacity of 174.9 mAh g-1 with holding 93% reversible capacity at 1 C after 80 cycles, and can maintain a discharge capacity of 175.3 mAh g-1 at 5 C rate. With increasing Ni content, the initial specific capacity increases while the cycling and rate performance degrades in some extent. These satisfying results demonstrate that spray pyrolysis is a powerful and efficient synthesis technology for producing Ni-rich layered cathode（Ni content 〉 80%）.

关键词： Lithium-ion batteries Nickel-rich layered cathode Ultrasonic spray pyrolysis powder technology Composite materials

Enhanced Oxidation Resistance of Iron Nanoparticles via Surface Modification in Chemical Vapor Condensation Process

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Journal of Materials Science & technology 2010年第4期26卷 367-370页

作者： Dong-Won Lee Ji-Hun Yu Taesuk Jang Byoung-Kee Kim Korea Institute of Materials Science Changwon 641-831 Korea Department of Electronic Materials Sunmoon University Asan 336-708 Korea 不详

In order to prevent the oxide formation on the surface of nano-size iron particles and thereby to improve the oxidation resistance in ordinary condition, iron nanoparticles synthesized by a chemical vapor condensation method were directly soaked in hexadecanethiol solution to coat them with a polymer layer. Oxygen content in the polymer-coated iron nanoparticles was significantly lower than that in usual air-passivated particles possessing iron-core/oxide-shell structure. Accordingly, oxidation resistance of the polymer-coated particles at an elevated temperature below 130℃ in air was 10-40 times higher than that of the normally passivated particles.

关键词： powder technology Nano materials Iron Chemical vapor condensation

Structural,electrical and magnetic studies on Y-Fe-O system

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Journal of Rare Earths 2009年第6期27卷 1013-1017页

作者： Anbarasu Venugopalan Manigandan Appasamy Sathiyakumar Saravanan Kaliyaperumal Kothandaraman Jayabalan Kothandaraman Department of Physics Anna University Department of Physics Pondicherry Engineering College

The compounds of iron substituted yttrium oxide systems have been prepared for the importance in the field of magneto electric *** polycrystalline samples of Y2–xFexO3–y(x=0.1,0.2) were prepared by solid-state reaction *** single-phase formation of these compounds was confirmed by X-ray diffraction *** was found that the samples crystallized in tetragonal phase and the lattice parameters were calculated as a=1.0559(7) nm,c=1.0832(9) nm for Y1.9Fe0.1O3–y and a=1.0545(6) nm,c=1.0841(8)...

关键词： magnetoelectric materials characterization methods powder technology diffused reflectance spectroscopy vibrating sample magnetometer electron paramagnetic resonance rare earths

Plasma preparation and low-temperature sintering of spherical TiC –Fe composite powder

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International Journal of Minerals,Metallurgy and Materials 2015年第12期22卷 1328-1333页

作者： Jian-jun Wang Jun-jie Hao Zhi-meng Guo Song Wang Institute for Advanced Materials and technology University of Science and Technology Beijing Research and Development Center CSR Qingdao Sifang Co. Ltd.

A spherical Fe matrix composite powder containing a high volume fraction （82vo1%） of fine TiC reinforcement was produced using a novel process combining in situ synthesis and plasma techniques. The composite powder exhibited good sphericity and a dense structure, and the fine sub-micron TiC particles were homogeneously distributed in the α-Fe matrix. A TiC-Fe cermet was prepared from the as-prepared spherical composite powder using powder metallurgy at a low sintering temperature; the product exhibited a hardness of HRA 88.5 and a flexural strength of 1360 MPa. The grain size of the fine-grained TiC and special surface structure of the spherical powder played the key roles in the fabrication process.

关键词： powder technology cermets radio frequency plasma sintering numerical simulation