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Research progress of permanent ferrite magnet materials
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作者 XU Bin CHEN Yu-feng +3 位作者 ZHOU Yu-juan LUO Bi-yun ZHONG Shou-guo LIU Xing-ao 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期1723-1762,共40页
Permanent ferrite magnet materials are extensively employed due to their exceptional magnetic properties and cost-effectiveness.The fast development in electromobile and household appliance industries contributes to a... Permanent ferrite magnet materials are extensively employed due to their exceptional magnetic properties and cost-effectiveness.The fast development in electromobile and household appliance industries contributes to a new progress in permanent ferrite materials.This paper reviews the deveolpement and progress of permanent ferrite magnet industry in recent years.The emergence of new raw material,the advancement of perparation methods and manufacturing techniques,and the potential applications of permanent ferrite materials are introduced and discussed.Specifically,nanocrystallization plays a crucial role in achieving high performance at a low cost and reducing reliance on rare earth resources,and therefore it could be a promising development trendency. 展开更多
关键词 permanent ferrite magnetic materials HIGH-PERFORMANCE nanosizing
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Photocatalytic application of magnesium spinel ferrite in wastewater remediation:A review
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作者 Rohit Jasrotia Nikhil Jaswal +3 位作者 Jyoti Prakash Chan Choon Kit Jagpreet Singh Abhishek Kandwal 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期490-505,共16页
This review paper explores the efficacy of magnesium ferrite-based catalysts in photocatalytic degradation of organic contaminates(antibiotic and dyes).We report the influence of different doping strategies,synthesis ... This review paper explores the efficacy of magnesium ferrite-based catalysts in photocatalytic degradation of organic contaminates(antibiotic and dyes).We report the influence of different doping strategies,synthesis methods,and composite materials on the degradation efficiency of these pollutants.Our analysis reveals the versatile and promising nature of magnesium ferrite-based catalysts,offering the valuable insights into their practical application for restoring the environment.Due to the smaller band gap and magnetic nature of magnesium ferrite,it holds the benefit of utilising the broader spectrum of light while also being recoverable.The in-depth analysis of magnesium ferrites'photocatalytic mechanism could lead to the development of cheap and reliable photocatalyst for the wastewater treatment.This concise review offers a thorough summary of the key advancements in this field,highlighting the pivotal role of the magnesium ferrite based photocatalysts in addressing the pressing global issue of organic pollutants in wastewater. 展开更多
关键词 Magnesium ferrite WASTEWATER DYES ANTIBIOTICS Photocatalytic degradation
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Effective Elimination of Hazardous Chromium (VI) Using Periodic Elements and Contemporary Adsorption Methods by Using Magnesium Ferrite Nanoparticle: A Review
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作者 Nazmun Nahar Mahabub Hossain Swaron +1 位作者 Md. Aliuzzaman Sheik Md. Jamal Uddin 《Journal of Environmental Protection》 2024年第5期596-619,共24页
A well-known hazardous metal and top contaminant in wastewater is hexavalent chromium. The two forms of most commonly found chromium are chromate ( CrO 4 2− ) and dichromate ( Cr 2 O 7 2− ). Leather tanning, cooling t... A well-known hazardous metal and top contaminant in wastewater is hexavalent chromium. The two forms of most commonly found chromium are chromate ( CrO 4 2− ) and dichromate ( Cr 2 O 7 2− ). Leather tanning, cooling tower blow-down, plating, electroplating, rinse water sources, anodizing baths etc. are the main sources of Cr (VI) contamination. The Cr (VI) is not only non-biodegradable in the environment but also carcinogenic to living population. It is still difficult to treat Cr contaminated waste water effectively, safely, eco-friendly, and economically. As a result, many techniques have been used to treat Cr (VI)-polluted wastewater, including adsorption, chemical precipitation, coagulation, ion-exchange, and filtration. Among these practices, the most practical method is adsorption for the removal of Cr (VI) from aqueous solutions, which has gained widespread acceptance due to the ease of use and affordability of the equipment and adsorbent. It has been revealed that Fe-based adsorbents’ oxides and hydroxides have high adsorptive potential to lower Cr (VI) content below the advised threshold. Fe-based adsorbents were also discovered to be relatively cheap and toxic-free in Cr (VI) treatment. Fe-based adsorbents are commonly utilized in industry. It has been discovered that nanoparticles of Fe-, Ti-, and Cu-based adsorbents have a better capacity to remove Cr (VI). Cr (VI) was effectively removed from contaminated water using mixed element-based adsorbents (Fe-Mn, Fe-Ti, Fe-Cu, Fe-Zr, Fe-Cu-Y, Fe-Mg, etc.). Initial findings suggest that Cr (VI) removal from wastewater may be accomplished by using magnesium ferrite nanomaterials as an efficient adsorbent. 展开更多
关键词 Chromium (VI) Periodic Elements Adsorption ELIMINATION Magnesium ferrite
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Enhancing layered perovskite ferrites with ultra-high-density nanoparticles via cobalt doping for ceramic fuel cell anode
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作者 Shuo Zhai Rubao Zhao +9 位作者 Hailong Liao Ling Fu Senran Hao Junyu Cai Yifan Wu Jian Wang Yunhong Jiang Jie Xiao Tao Liu Heping Xie 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第9期39-48,共10页
Nanoparticles anchored on the perovskite surface have gained considerable attention for their wide-ranging applications in heterogeneous catalysis and energy conversion due to their robust and integrated structural co... Nanoparticles anchored on the perovskite surface have gained considerable attention for their wide-ranging applications in heterogeneous catalysis and energy conversion due to their robust and integrated structural configuration.Herein,we employ controlled Co doping to effectively enhance the nanoparticle exsolution process in layered perovskite ferrites materials.CoFe alloy nanoparticles with ultra-high-density are exsolved on the(PrBa)_(0.95)(Fe_(0.8)Co_(0.1)Nb_(0.1))2O_(5+δ)(PBFCN_(0.1))surface under reducing atmosphere,providing significant amounts of reaction sites and good durability for hydrocarbon catalysis.Under a reducing atmosphere,cobalt facilitates the reduction of iron cations within PBFCN_(0.1),leading to the formation of CoFe alloy nanoparticles.This formation is accompanied by a cation exchange process,wherein,with the increase in temperature,partial cobalt ions are substituted by iron.Meanwhile,Co doping significantly enhance the electrical conductivity due to the stronger covalency of the Cosingle bondO bond compared with Fesingle bondO bond.A single cell with the configuration of PBFCN_(0.1)-Sm_(0.2)Ce_(0.8)O_(1.9)(SDC)|SDC|Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ)(BSCF)-SDC achieves an extremely low polarization resistance of 0.0163Ωcm^(2)and a high peak power density of 740 mW cm^(−2)at 800℃.The cell also shows stable operation for 120 h in H_(2)with a constant current density of 285 mA cm^(−2).Furthermore,employing wet C_(2)H_(6)as fuel,the cell demonstrates remarkable performance,achieving peak power densities of 455 mW cm^(−2)at 800℃and 320 mW cm^(−2)at 750℃,marking improvements of 36%and 70%over the cell with(PrBa)_(0.95)(Fe_(0.9)Nb_(0.1))_(2)O_(5+δ)(PBFN)-SDC at these respective temperatures.This discovery emphasizes how temperature influences alloy nanoparticles exsolution within doped layered perovskite ferrites materials,paving the way for the development of high-performance ceramic fuel cell anodes. 展开更多
关键词 Solid oxide fuel cell ANODE Ethane fuel NANOPARTICLE EXSOLUTION Layered perovskite ferrites
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A Design of Modular Interior Ferrite Magnet Fluxswitching Linear Motor for Track Transport
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作者 Zongsheng Zhang Hao Wang Hong Chen 《CES Transactions on Electrical Machines and Systems》 EI CSCD 2024年第3期284-294,共11页
A novel topology of modular ferrite magnet fluxswitching linear motor(FMFSLM)use for track transport is presented in this paper,which enables more ferrite magnets to be inserted into the primary iron core.The motor ha... A novel topology of modular ferrite magnet fluxswitching linear motor(FMFSLM)use for track transport is presented in this paper,which enables more ferrite magnets to be inserted into the primary iron core.The motor has a significant low-cost advantage in long-distance linear drive.The proposed FMFSLM’s structure and working principle were introduced.Further,the thrust force expression of the motor was established.The thrust force components triggering thrust force ripple were investigated,and their expressions can be obtained according to the inductances’Fourier series expressions.Resultantly,the relationship between the harmonics of thrust force and that of self-and mutual inductances was revealed clearly.Based on the relationship,a skewed secondary should be practical to reduce the thrust force ripple.Thus,the effect of employing a skewed secondary to the proposed FMFSLM was investigated,and an optimized skewing span distance was determined.Finite element analysis(FEA)was conducted to validate the exactness of the theoretical analysis.The simulation results indicate that the strategy of suppressing thrust force ripple has a significant effect.Meanwhile,the motor maintains a good efficiency characteristic.The results of the prototype experiment are in good agreement with FEAs,which further verifies the proposed modular interior FMFSLM’s practicability. 展开更多
关键词 ferrite magnet flux-switching linear motor(FMFSLM) Detent force Resistance force Force ripple Skewed secondary
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Research on Heredity of Coarse Ferrite Grains
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作者 Wangzhan FAN Weimin GUI Youfeng CHEN 《Research and Application of Materials Science》 2024年第1期5-8,共4页
The changes in austenite grain size of the specimens with coarse ferrite grains under different heat treatment process were investigated.The focus was on studying the effect of annealing on refining coarse ferrite gra... The changes in austenite grain size of the specimens with coarse ferrite grains under different heat treatment process were investigated.The focus was on studying the effect of annealing on refining coarse ferrite grains,as well as the influence of the ferrite grain size on the main technical indicators of gas carburizing.The results show that coarse ferrite grains may not necessarily cause the coarse austenite grains,but may result in mixed austenite grains.After annealing treatment,the coarse ferrite grains can be significantly refined and homogenized.Moreover,the coarse ferrite grains have no significant effects on hardnessand intergranular oxidationof gas carburizing. 展开更多
关键词 grain size coarse ferrite grains AUSTENITE gas carburizing
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辽-吉古元古代造山带杉松岗钴镍铜矿床Ni-Co超常富集成矿过程初探 被引量:1
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作者 王慧宁 刘福来 +2 位作者 王舫 田忠华 刘冰 《岩石学报》 SCIE EI CAS CSCD 北大核心 2024年第10期2971-2987,共17页
镍和钴是我国紧缺关键金属矿产,对国民经济和社会发展具有重要战略意义。我国现有镍、钴资源储量匮乏,对外依存度极高。因此,立足国内,加强镍-钴成矿规律研究与找矿战略行动迫在眉睫。吉林省临江市杉松岗变沉积岩容矿型钴镍铜矿床位于辽... 镍和钴是我国紧缺关键金属矿产,对国民经济和社会发展具有重要战略意义。我国现有镍、钴资源储量匮乏,对外依存度极高。因此,立足国内,加强镍-钴成矿规律研究与找矿战略行动迫在眉睫。吉林省临江市杉松岗变沉积岩容矿型钴镍铜矿床位于辽-吉古元古代造山带东北段。有关该矿床Ni-Co的赋存状态、富集成矿期次与成矿规律等研究十分薄弱。本文通过对杉松岗钴镍铜矿床Ni-Co矿石和赋矿围岩开展显微结构观察、扫描电镜-能谱分析、矿物原位硫同位素分析和电子探针测试等系统研究,发现该矿床Ni-Co的富集成矿经历了多期多阶段复杂的变质变形和热液作用的叠加改造过程。其中,变质变形阶段以辉砷钴矿和黄铜矿等呈微细粒包体赋存于变质矿物中为特点;而热液阶段又可分为早期和晚期。早期热液作用以大量镍钴矿物(辉砷钴矿、硫镍矿和镍黄铁矿)伴生滑石化、白云石化和硅化蚀变为标志,为Ni-Co超常富集成矿的主成矿期,其硫化物的硫同位素分布范围集中(10.92‰~13.67‰),且与珍珠门组白云石大理岩内硫化物的δ^(34) S值接近,推断Ni、Co主要来自深部岩浆热液,即含矿流体向上迁移过程中强烈淋滤并萃取珍珠门组地层内的硫,最终在大栗子组地层发生硫化物沉淀并富集成矿。晚期热液作用主要沉淀铜铁硫化物(黄铜矿、磁黄铁矿和黄铁矿)和极少量钴镍黄铁矿、硫镍钴矿和镍黄铁矿,伴生方解石化、硅化和绿泥石化蚀变,硫化物的δ^(34) S值(6.53‰~8.59‰)与侏罗纪花岗岩体及同期的金等多金属硫化物矿床的硫同位素组成一致,表明晚期岩浆热液可能与古太平洋俯冲事件有关。杉松岗钴镍铜矿床Ni主要以硫镍矿和镍黄铁矿的形式赋存,次为钴镍黄铁矿和硫镍钴矿。Co主要以辉砷钴矿形式赋存,次为硫镍矿、镍黄铁矿、钴镍黄铁矿和硫镍钴矿。有关该矿未来Ni-Co找矿勘查设想,建议以滑石化和白云石化为主要找矿标志。结合前人研究成果,本文提出杉松岗钴镍铜矿床为沉积-变质变形-多期热液叠加改造的复合造山型钴镍铜矿床,原始的沉积和成岩作用为钴矿的初始预富集提供了重要的成矿条件与背景,古元古代碰撞造山与区域变质变形事件对Co的初始活化-迁移起着关键的控制作用,富Ni-Co的深部岩浆热液作用主导了Ni-Co的超常富集与成矿;而燕山期中酸性岩浆热液作用对Ni-Co富集矿段起到了肢解作用,故不利于Ni-Co的富集成矿。 展开更多
关键词 杉松岗钴镍铜矿床 ni-co的赋存状态 变质-热液作用 蚀变类型 找矿标志
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Absorption-Dominant mmWave EMI Shielding Films with Ultralow Reflection using Ferromagnetic Resonance Frequency Tunable M-Type Ferrites 被引量:2
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作者 Horim Lee Seung Han Ryu +3 位作者 Suk Jin Kwon Jae Ryung Choi Sang‑bok Lee Byeongjin Park 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第6期1-23,共23页
Although there is a high demand for absorption-dominant electromagnetic interference(EMI) shielding materials for 5G millimeter-wave(mmWave) frequencies, most current shielding materials are based on reflection-domina... Although there is a high demand for absorption-dominant electromagnetic interference(EMI) shielding materials for 5G millimeter-wave(mmWave) frequencies, most current shielding materials are based on reflection-dominant conductive materials. While there are few absorption-dominant shielding materials proposed with magnetic materials, their working frequencies are usually limited to under 30 GHz. In this study, a novel multi-band absorption-dominant EMI shielding film with M-type strontium ferrites and a conductive grid is proposed. This film shows ultralow EMI reflection of less than 5% in multiple mmWave frequency bands with sub-millimeter thicknesses, while shielding more than 99.9% of EMI. The ultralow reflection frequency bands are controllable by tuning the ferromagnetic resonance frequency of M-type strontium ferrites and composite layer geometries. Two examples of shielding films with ultralow reflection frequencies, one for 39 and 52 GHz 5G telecommunication bands and the other for 60 and 77 GHz autonomous radar bands, are presented. The remarkably low reflectance and thinness of the proposed films provide an important advancement toward the commercialization of EMI shielding materials for 5G mmWave applications. 展开更多
关键词 5G communication MmWave EMI shielding M-type ferrites
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Ni-Co过渡金属化合物在超级电容器中的研究进展
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作者 何宇平 苏钰 +3 位作者 姚常娟 李军 吴涛涛 唐建国 《当代化工研究》 CAS 2024年第18期24-26,共3页
Ni-Co过渡金属化合物相对于二元过渡金属氧化物具有更高的导电率和电化学反应活性位点,作为电极材料展现出了良好的速率性能和循环稳定性。Ni-Co过渡金属氧化物具有较大的比电容,但导电率较低,速率性能较差,所以在Ni-Co过渡金属的基础... Ni-Co过渡金属化合物相对于二元过渡金属氧化物具有更高的导电率和电化学反应活性位点,作为电极材料展现出了良好的速率性能和循环稳定性。Ni-Co过渡金属氧化物具有较大的比电容,但导电率较低,速率性能较差,所以在Ni-Co过渡金属的基础上掺杂S元素或碳材料,有利于增加电化学反应位点和氧化还原反应,从而提高复合材料的导电性、稳定性。本文以Ni-Co过渡金属为主,对其三元氧化物、三元硫化物、三元氧化物与碳材料复合改性研究进行了综述,并对未来Ni-Co过渡金属发展进行了展望。 展开更多
关键词 电化学 ni-co 过渡金属 超级电容器 电极材料
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Hysteresis loss free soft magnetic ferrites based on Larmor precession
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作者 冯双久 赵幸丽 +3 位作者 朱守金 吕庆荣 阚绪材 刘先松 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第8期433-438,共6页
A big enough transverse magnetic field applied to soft magnetic ferrite toroid can magnetize the ferrite to a saturation level in transverse direction and almost completely suppresses magnetic domain structures in the... A big enough transverse magnetic field applied to soft magnetic ferrite toroid can magnetize the ferrite to a saturation level in transverse direction and almost completely suppresses magnetic domain structures in the ferrite,the response to the longitudinal alternating electromagnetic field changes from the original domain wall displacements and spin rotations to the precession of magnetization around the transverse field,and the hysteresis loss disappears in the ferrites.Both theoretical and experimental results indicate that the permeability and magnetic loss in the ferrite can be controlled by adjusting the transverse magnetic field.A higher Q value with relatively low permeability can be achieved by increasing the transverse field,which ensures that the ferrite can be operated at high frequencies,with magnetic loss being very low. 展开更多
关键词 ferrites Larmor precession magnetic losses hysteresis loss free
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Low Temperature Heat Capacity of Zn Substituted Cobalt Ferrite Nanosphere:The Relation between Magnetic Properties and Microstructure
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作者 YUAN Meng GU Xiaojie +4 位作者 FU Jie WANG Shaoxu SHI Quan TAN Zhicheng XU Fen 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第5期984-995,共12页
Co_((1-x))ZnxFe_(2)O_(4)nanospheres(x=0,0.5,0.8)with a unidirectional cubic spinel structure were prepared by a solvothermal method.By using a range of theoretical and empirical models,the experimental heat capacity v... Co_((1-x))ZnxFe_(2)O_(4)nanospheres(x=0,0.5,0.8)with a unidirectional cubic spinel structure were prepared by a solvothermal method.By using a range of theoretical and empirical models,the experimental heat capacity values were fitted as a function of temperature over a suitable temperature range to explain the possible relationship between the magnetic properties and microstructure of the nanospheres.As a result,at a low temperature(T<10 K),the parameter Bfswdecreases with increasing Zn concentration,implying that the exchange interaction between A and B sites decreases.At a relatively high temperature(T>50 K),the Debye temperature decreases with increasing Zn concentration,which is due to the weakening of the interatomic bonding force after the addition of non-magnetic materials to the Co Fe_(2)O_(4)spinel ferrite. 展开更多
关键词 Co-Zn spinal ferrite nanospheres magnetic properties heat capacity thermodynamic functions PPMS
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Green synthesis of three-dimensional magnesium ferrite/titanium dioxide/reduced graphene from Garcinia mangostana extract for crystal violet photodegradation and antibacterial activity
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作者 Tong Hoang Lin Che Quang Cong +10 位作者 Nguyen Thanh Hoai Nam Hoang An Nguyen Duy Hai Ton That Buu Thoi Le Nhat Binh Hoang Le Minh Lam Thanh Ngan Hoang Thuy Kim Ngan Du Chi Vi Ta Dang Khoa Nguyen Huu Hieu 《Journal of Semiconductors》 EI CAS CSCD 2023年第12期111-124,共14页
In this study,three-dimensional porous magnesium ferrite/titanium dioxide/reduced graphene oxide(Mg Fe_2O_(4)-GM/TiO_(2)/rGO(MGTG))was successfully synthesized via green and hydrothermal-supported co-precipitation met... In this study,three-dimensional porous magnesium ferrite/titanium dioxide/reduced graphene oxide(Mg Fe_2O_(4)-GM/TiO_(2)/rGO(MGTG))was successfully synthesized via green and hydrothermal-supported co-precipitation methods using the extract of Garcinia mangostana(G.mangostana)as a reducing agent.The characterization results indicate the successful formation of the nano/micro Mg Fe_(2)O_(4)(MFO)and TiO_(2) on the structure of the reduced graphene oxide(rGO),which can also act as efficient support,alleviating the agglomeration of the nano/micro MFO and TiO_(2).The synergic effects of the adsorption and photodegradation activity of the material were investigated according to the removal of crystal violet(CV)under ultraviolet light.The effects of catalyst dosage,CV concentration,and p H on the CV removal efficiency of the MGTG were also investigated.According to the results,the CV photodegradation of the MGTG-200 corresponded to the pseudo-first-order kinetic model.The reusability of the material after 10 cycles also showed a removal efficiency of 92%.This happened because the materials can easily be recollected using external magnets.In addition,according to the effects of different free radicals·O_(2)^(-),h^(+),and·OH on the photodegradation process,the photocatalysis mechanism of the MGTG was also thoroughly suggested.The antibacterial efficiency of the MGTG was also evaluated according to the inhibition of the Gram-positive bacteria strain Staphylococcus aureus(S.aureus).Concurrently,the antibacterial mechanism of the fabricated material was also proposed.These results confirm that the prepared material can be potentially employed in a wide range of applications,including wastewater treatment and antibacterial activity. 展开更多
关键词 magnesium ferrite titanium dioxide reduced graphene oxide Garcinia mangostana PHOTODEGRADATION ANTIBACTERIAL
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Al_(2)O_(3)浓度对柔性摩擦辅助电镀Ni-Co复合镀层性能的影响
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作者 史晓彤 张伟强 +4 位作者 吕镖 陶绍虎 刘贺 柳泉 郭策安 《辽宁化工》 CAS 2024年第8期1156-1159,共4页
利用柔性摩擦辅助电沉积在炮钢表面制备n-Al_(2)O_(3)/Ni-Co复合镀层,研究镀液中Al_(2)O_(3)浓度对Ni-Co复合镀层的组织结构和性能影响。结果表明,当Al_(2)O_(3)为5 g·L^(-1)时,镀层平均晶粒尺寸最小(9.6 nm),显微硬度最大(573.28 ... 利用柔性摩擦辅助电沉积在炮钢表面制备n-Al_(2)O_(3)/Ni-Co复合镀层,研究镀液中Al_(2)O_(3)浓度对Ni-Co复合镀层的组织结构和性能影响。结果表明,当Al_(2)O_(3)为5 g·L^(-1)时,镀层平均晶粒尺寸最小(9.6 nm),显微硬度最大(573.28 HV);腐蚀电化学研究表明,此时镀层自腐蚀电位正移至-0.304 V,自腐蚀电流较小(1.313μA·cm^(-2)),耐腐蚀性较好。 展开更多
关键词 Al_(2)O_(3)浓度 ni-co复合镀层 晶粒尺寸 显微硬度 耐腐蚀性
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Effect of Interface Form on Creep Failure and Life of Dissimilar Metal Welds Involving Nickel-Based Weld Metal and Ferritic Base Metal 被引量:1
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作者 Xiaogang Li Junfeng Nie +2 位作者 Xin Wang Kejian Li Haiquan Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第1期265-285,共21页
For dissimilar metal welds(DMWs)involving nickel-based weld metal(WM)and ferritic heat resistant steel base metal(BM)in power plants,there must be an interface between WM and BM,and this interface suffers mechanical a... For dissimilar metal welds(DMWs)involving nickel-based weld metal(WM)and ferritic heat resistant steel base metal(BM)in power plants,there must be an interface between WM and BM,and this interface suffers mechanical and microstructure mismatches and is often the rupture location of premature failure.In this study,a new form of WM/BM interface form,namely double Y-type interface was designed for the DMWs.Creep behaviors and life of DMWs containing double Y-type interface and conventional I-type interface were compared by finite element analysis and creep tests,and creep failure mechanisms were investigated by stress-strain analysis and microstructure characterization.By applying double Y-type interface instead of conventional I-type interface,failure location of DMW could be shifted from the WM/ferritic heat-affected zone(HAZ)interface into the ferritic HAZ or even the ferritic BM,and the failure mode change improved the creep life of DMW.The interface premature failure of I-type interface DMW was related to the coupling effect of microstructure degradation,stress and strain concentrations,and oxide notch on the WM/HAZ interface.The creep failure of double Y-type interface DMW was the result of Type IV fracture due to the creep voids and micro-cracks on fine-grain boundaries in HAZ,which was a result of the matrix softening of HAZ and lack of precipitate pinning at fine-grain boundaries.The double Y-type interface form separated the stress and strain concentrations in DMW from the WM/HAZ interface,preventing the trigger effect of oxide notch on interface failure and inhibiting the interfacial microstructure cracking.It is a novel scheme to prolong creep life and enhance reliability of DMW,by means of optimizing the interface form,decoupling the damage factors from WM/HAZ interface,and then changing the failure mechanism and shifting the failure location. 展开更多
关键词 Dissimilar metal weld Nickel-based weld metal ferritic heat resistant steel INTERFACE Creep strain MICROSTRUCTURE Failure mechanism Creep life
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Tuning magneto-dielectric properties of Co_(2)Z ferrites via Gd doping for high-frequency applications
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作者 武剑 卢冰 +6 位作者 张颖 陈一鑫 孙凯 陈大明 李强 刘颖力 李颉 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期468-473,共6页
Magneto-dielectric properties of Co_(2)Z ferrite materials are tuned via Gd doping for applications in high-frequency antennas and filters in the present work.Ba_(3)Co_(2)Fe_(24-x)Gd_(x)O_(41)(x=0.00,0.05,0.10,0.15,an... Magneto-dielectric properties of Co_(2)Z ferrite materials are tuned via Gd doping for applications in high-frequency antennas and filters in the present work.Ba_(3)Co_(2)Fe_(24-x)Gd_(x)O_(41)(x=0.00,0.05,0.10,0.15,and 0.20)materials are successfully prepared by using solid-state method at 925℃for 4 h with 2.5-wt%Bi_(2)O_(3)sintering aids.The content of Gd^(3+)ion can affect micromorphology,grain size,bulk density,and magneto-dielectric properties of the ferrite.With Gd^(3+)ion content increasing,saturation magnetization(Ms)first increases and then decreases.The maximum value of Ms is 44.86 emu/g at x=0.15.Additionally,sites occupied by Gd^(3+)ions can change magnetic anisotropy constant of the ferrite.Magnetocrystalline anisotropy constant(K_1)is derived from initial magnetization curve,and found to be related to spin-orbit coupling and intersublattice interactions between metal ions.The real part of magnetic permeability(μ′)and real part of dielectric permittivity(ε′)are measured in a frequency range of 10 MHz-1 GHz.When x=0.15,material has excellent magneto-dielectric properties(μ′≈12.2 andε′≈17.61),low magnetic loss(tanδμ≈0.03 at 500 MHz),and dielectric loss(tanδε≈0.04 at 500 MHz).The results show that Gd-doped Co_(2)Z ferrite has broad application prospects in multilayer filters and high-frequency antennas. 展开更多
关键词 Co_(2)Z ferrite magneto-dielectric properties Gd doping high-frequency applications
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A new step-cooling process for strength and toughness matching control of vanadium-containing railway wheels:effect of intragranular ferrite
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作者 YAO Sancheng LIU Xuehua +3 位作者 ZHAO Hai JIANG Bo CHEN Gang XU Kang 《Baosteel Technical Research》 CAS 2023年第3期40-48,共9页
To improve the competitive relationship between strength and toughness,the effect of low undercooling in austenite(γ)on the microstructure and mechanical properties of commercial vanadium-containing wheel steels was ... To improve the competitive relationship between strength and toughness,the effect of low undercooling in austenite(γ)on the microstructure and mechanical properties of commercial vanadium-containing wheel steels was studied using an optical microscope(OM),a scanning electron microscope(SEM),a transmission electron microscope(TEM),and mechanical property tests.The results show that when the wheel steel is slightly cooled to an appropriate temperature above A c3 point for a short time after it has been austenitized at an elevated temperature,the solid-solved vanadium is pre-precipitated in the form of V(C,N)second phase semicoherent with the matrix in the originalγgrain.This phase hardly participates in matrix strengthening.Due to the small mismatch between V(C,N)and ferrite(α),during the subsequent-cooling phase transformation stage,the pre-precipitated second phase becomes theαnucleation point,causing granular and ellipsoidal intragranular ferrite(IGF,with an average size of 4-6μm)to nucleate in the originalγ.The IGF production and strength loss increases with the increasing undercooling degree.Based on this,Masteel Co.,Ltd.has developed a new heat-treatment step-cooling process that can promote the formation of IGF,considerably improving the level and uniformity of fracture toughness on the premise that the strength and hardness of the wheel are almost unchanged. 展开更多
关键词 vanadium microalloyed railway wheel strength and toughness match low undercooling in austenite intragranular ferrite second phase step-cooling process
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Effect of Substitution of Al for Fe on Magnetic Properties and Particle Size of Ni-Co Nanoferrite
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作者 Ahmad Amirabadizadeh Tyebeh Amirabadi 《World Journal of Condensed Matter Physics》 2013年第3期131-135,共5页
Nanocrystalline Al doped nickel-cobalt ferrite [Ni0.6Co0.4Fe2-xAlxO4 (x = 0.0, 0.1, 0.3, 0.5 and 0.7)] powders have been synthesized by sol-gel auto-ignition method and the effect of non-magnetic aluminum content on t... Nanocrystalline Al doped nickel-cobalt ferrite [Ni0.6Co0.4Fe2-xAlxO4 (x = 0.0, 0.1, 0.3, 0.5 and 0.7)] powders have been synthesized by sol-gel auto-ignition method and the effect of non-magnetic aluminum content on the nanosize particles and magnetic properties has been studied. The X-ray diffraction (XRD) revealed that the powders obtained are single phase with inverse spinel structure. The calculated grain size from XRD data have been verified using transmission electron microscopy (TEM). TEM photograph shows that the powders consist of nano meter sized grain. The size of nanoparticles decreases as the non magnetic Al content increases. Magnetic hysteresis loops were measured at room temperature with maximum applied magnetic field of 20 KOe. As aluminum content increases, the measured magnetic hysteresis curves became narrow and saturation magnetization (Ms), and coercive force (Hc) decreased. The reduction of magnetization with the increase of aluminum content is caused by non-magnetic Al3+ ions and weakened interaction between sub-lattices. 展开更多
关键词 SOL-GEL Particle Size Magnetic Properties Nickel-Cobalt ferrite
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Grain boundary engineering for enhancing intergranular damage resistance of ferritic/martensitic steel P92
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作者 Lei Peng Shang-Ming Chen +6 位作者 Jing-Yi Shi Yong-Jie Sun Yi-Fei Liu Yin-Zhong Shen Hong-Ya He Hui-Juan Wang Jie Tian 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第5期186-199,共14页
Ferritic/martensitic(F/M)steel is widely used as a structural material in thermal and nuclear power plants.However,it is susceptible to intergranular damage,which is a critical issue,under service conditions.In this s... Ferritic/martensitic(F/M)steel is widely used as a structural material in thermal and nuclear power plants.However,it is susceptible to intergranular damage,which is a critical issue,under service conditions.In this study,to improve the resistance to intergranular damage of F/M steel,a thermomechanical process(TMP)was employed to achieve a grain boundary engineering(GBE)microstructure in F/M steel P92.The TMP,including cold-rolling thickness reduction of 6%,9%,and 12%,followed by austenitization at 1323 K for 40 min and tempering at 1053 K for 45 min,was applied to the as-received(AR)P92 steel.The prior austenite grain(PAG)size,prior austenite grain boundary character distribution(GBCD),and connectivity of prior austenite grain boundaries(PAGBs)were investigated.Compared to the AR specimen,the PAG size did not change significantly.The fraction of coincident site lattice boundaries(CSLBs,3≤Σ≤29)and Σ3^(n) boundaries along PAGBs decreased with increasing reduction ratio because the recrystallization fraction increased with increasing reduction ratio.The PAGB connectivity of the 6%deformed specimen slightly deteriorated compared with that of the AR specimen.Moreover,potentiodynamic polarization studies revealed that the intergranular damage resistance of the studied steel could be improved by increasing the fraction of CSLBs along the PAGBs,indicating that the TMP,which involves low deformation,could enhance the intergranular damage resistance. 展开更多
关键词 Grain boundary engineering ferritic/martensitic steel Prior austenite grain boundary character distribution Grain boundary connectivity Intergranular damage resistance
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Effect of Ni content on the weldability of middle-chromium hyperpure ferritic stainless steels 00Cr21Ti
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作者 ZHANG Xinbao WANG Zhibin +2 位作者 SUN Mingshan YAN Zhifeng WANG Wenxian 《Baosteel Technical Research》 CAS 2024年第2期19-26,共8页
Excellent weldability substantially contributes to the intrinsic quality of steels,while appropriate chemical composition plays a primary role in the essential weldability of steels.The poor weldability of ferritic st... Excellent weldability substantially contributes to the intrinsic quality of steels,while appropriate chemical composition plays a primary role in the essential weldability of steels.The poor weldability of ferritic stainless steels could be improved through modification with minor alloy elements while minimally increasing the cost.Therefore,studying the effect of minor alloy elements on the weldability of steels is of considerable importance.In this study,several steels of middle-chromium hyperpure ferritic stainless 00Cr21Ti with different Ni content(0.3%,0.5%,0.8%,and 1.0%)were developed,and their weldabilities of butt joint samples welded using the metal inert gas welding process,including the influence of welded joints on the microstructure,tensile performance,corrosion resistance,and fatigue property,were investigated.Results show that the steels with w(Ni)≥0.8%exhibit excellent mechanical properties compared with those with low-Ni content steels,further,their impact toughness at normal atmospheric temperature meets the industrial application standard and the fatigue property is similar to that of 304 austenitic stainless steel.Moreover,results show that the corrosion resistance of all the samples is almost at the same level.The results acquired in this study are supposed to be useful for the optimization of the chemical composition of stainless steels aiming to improve weldability. 展开更多
关键词 00Cr21Ti ferritic stainless steel SUS443 welded joint mechanical properties fatigue property Ni content
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Ni-Co LDH/板钛矿TiO2二维/一维复合材料的制备及光催化降解环丙沙星研究
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作者 胡炳文 姜敏俊 程刚 《材料科学》 2024年第9期1309-1318,共10页
通过在镍钴双金属氢氧化物(Ni-Co LDH)的合成体系中引入胺修饰板钛矿TiO2得到了Ni-Co LDH/TiO2复合光催化材料,并对其光催化降解环丙沙星(CIP)抗生素的活性进行了研究。扫描电子显微镜(SEM)显示Ni-Co LDH将棒状的板钛矿TiO2完全包裹,增... 通过在镍钴双金属氢氧化物(Ni-Co LDH)的合成体系中引入胺修饰板钛矿TiO2得到了Ni-Co LDH/TiO2复合光催化材料,并对其光催化降解环丙沙星(CIP)抗生素的活性进行了研究。扫描电子显微镜(SEM)显示Ni-Co LDH将棒状的板钛矿TiO2完全包裹,增大了材料与环丙沙星分子的接触面积。当TiO2与LDH的摩尔比为1:4时,复合材料表现出最佳的催化活性且Ni-Co LDH/TiO2(1:4)在四次循环实验后仍未出现明显的活性下降,说明其具有优异的稳定性。光电化学结果证明这种结构为光催化环丙沙星降解提供了更多的活性位点,其优异的光生电子与空穴的分离和传输效率是其具有最佳催化活性的主要原因。Ni-Co LDH/brookite TiO2 composite is prepared by adding amine-modified TiO2 into the fabrication system of Ni-Co layered bimetallic hydroxide (Ni-Co LDH), and its photocatalytic degradation of ciprofloxacin (CIP) antibiotic is studied. Scanning electron microscopy (SEM) images show that Ni-Co LDH wrapped on the brookite TiO2 increases the contact area between the catalyst and ciprofloxacin molecules. It is found that when the mole ratio of TiO2 to Ni-Co LDH is 1:4, the composite exhibits the best catalytic activity, and the activity of Ni-Co LDH/TiO2(1:4) has no decrease significantly after four cycles tests, indicating that it has excellent stability. The photochemical results show that this structure provides more active sites for photocatalytic ciprofloxacin degradation, and its excellent separation and transfer efficiency of photogenerated electrons and holes are the main reason for its optimal catalytic activity. 展开更多
关键词 光催化 板钛矿TiO2 ni-co LDH 抗生素降解 电荷分离
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