微波LTCC环行器用热压烧结SrFe12O19铁氧体的低温烧结特性

为了与低温共烧陶瓷（LTCC）技术兼容,本文采用热压烧结工艺在870 °C制备了添加不同Bi2O3含量的SrFe12O19铁氧体材料,着重研究了材料的晶相组成、烧结密度、气孔率和磁性能等低温烧结特性。研究结果表明,材料在870 °C烧结时,Bi2O3的添加促进了SrFe12O19晶相结构的形成,提高了材料的烧结致密度和磁性能。当Bi2O3的添加量为2～4 wt %,材料可以获得致密的结构,烧结密度达到4.65 g?cm-3以上,气孔率低于10%,材料的饱和磁化强度Ms和内禀矫顽力Hci较高,分别达到252.4 kA?m-1和312.9 kA?m-1以上。此外,基于SrFe12O19材料的低温烧结特性讨论了该材料在微波LTCC环行器当中的应用。     

LTCC系统用低温烧结SrFe_(12)O_(19)铁氧体性能的改善研究（英文）

采用固相法制备M型六角锶铁氧体(SrFe_(12)O_(19))材料,利用Bi_2O_3作为烧结助剂以改善材料的低温烧结特性,系统研究了材料的晶体结构、电学性能和磁学性能。结果表明:当烧结温度降低至900℃时可以获得单相的SrFe_(12)O_(19)铁氧体材料。Bi_2O_3的添加对低温烧结材料的电学性能和磁学性能影响显著,可以提高材料的电阻率ρ、饱和磁化强度M_s、內禀矫顽力H_(ci)和磁晶各向异性场H_a。低温烧结材料的ρ、M_s、H_(ci)和H_a分别可以达到0.42×10~8?·cm、285.6 k A·m~(-1)、347.3 kA·m~(-1)和1546.6 kA·m~(-1),在非互易LTCC(低温共烧陶瓷)铁氧体器件领域具有重要的应用前景。     

微波LTCC环行器用热压烧结SrFe_(12)O_(19)铁氧体的低温烧结特性（英文）

为了与低温共烧陶瓷(LTCC)技术兼容,采用热压烧结工艺在870℃制备了添加不同Bi_2O_3含量的SrFe_(12)O_(19)铁氧体材料,着重研究了材料的晶相组成、烧结密度、气孔率和磁性能等低温烧结特性。研究结果表明,材料在870℃烧结时,Bi_2O_3的添加促进了SrFe_(12)O_(19)晶相结构的形成,提高了材料的烧结致密度和磁性能。当Bi_2O_3的添加量(质量分数)为2%~4%,材料可以获得致密的结构,烧结密度达到4.65 g·cm~(-3)以上,气孔率低于10%,材料的饱和磁化强度Ms和内禀矫顽力Hci较高,分别达到252.4 k A·m~(-1)和312.9k A·m~(-1)以上。此外,基于SrFe_(12)O_(19)材料的低温烧结特性讨论了该材料在微波LTCC环行器当中的应用。     

低温烧结B2O3掺杂Y1.05Bi0.75Ca1.2Fe4.4V0.6O12铁氧体的微结构研究

用传统陶瓷工艺制备了0.025wt%B2O3掺杂的Y1.05Bi0.75Ca1.2Fe4.4V0.6O12铁氧体,并对其低温烧结特性进行了研究.结果表明,烧结温度对B2O3掺杂的Y1.05Bi0.75Ca1.2Fe4.4V0.6O12铁氧体的密度影响显著:样品在1040℃烧结,固相反应完全,且具有晶粒大小均匀、结构致密的显微结构.     

B2O3掺杂钇铁氧体的低温烧结及磁性能研究

用传统陶瓷工艺制备了B2O3掺杂的Y1.05Bi0.75Ca1.2Fe4.4V0.6O12铁氧体,并对其低温烧结特性进行了研究.结果表明:掺杂适量的B2O3能够明显降低铁氧体的烧结温度且对磁性能影响显著.当B2O3掺杂量为0.025wt%、烧结温度为1040℃时,可获得晶粒大小均匀、结构致密的铁氧体,其饱和磁感应强度为4.82×10-2T.     

针状纳米晶复合SrM铁氧体的制备及磁性研究

采用柠檬酸法和EDTA-柠檬酸联合络合法分别制各球状和针状纳米晶复合SrM铁氧体.用透射电镜、X射线衍射仪和振动样品磁强计对合成样品的粒度及形貌、物相、磁学性能进行研究.结果表明:当煅烧温度为850℃时,样品为纯的肘型六角锶铁氧体,且矫顽力达到最大;当温度低于850℃时,样品存在复相,直接煅烧的样品为SrFe12O19/α-Fe2O3纳米复合相,通过自蔓延燃烧处理的样品为SrFe12O19/γ-Fe2O3的纳米复合相.在750℃时制得的样品与纯的M型六角锶铁氧体相比,剩余磁化强度和饱和磁化强度有所提高.通过加入EDTA使锶铁氧体的形貌发生改变,矫顽力得到提高,最终制得粒径为30 nm,长径比为5:1,内禀矫顽力、比饱和磁化强度与比剩余磁化强度分别为6198.3×79.6 A·m-1、71.5A.m2·kg-1和42.3 A·m2·Kg-1的针状纳米复合SrM铁氧体.     

SiO2凝胶体系中M型锶铁氧体的制备及其磁性能

利用溶胶-凝胶法在SiO2凝胶体系中制备了纳米级的锶铁氧体磁性微粒，该磁性微粒组成为3O％SrFe12O19和70％SiO2(质量百分含量)。对该微粒进行了XRD分析，利用VSM对样品进行了磁性能研究。研究表明，相对于共沉淀法制备的纯锶铁氧体微粒，在SiO2凝胶体系中制备的SrM微粒仍保持为六方磁铅石型结构，但是粒径明显降低，850℃结样品的粒径约为31nm；且内禀矫顽力Hc有了显著的提高，850℃烧结样品的内禀矫顽力达到518．4kA／m，而比饱和磁化强度则有所下降。并对其磁性能变化的原因进行了分析。     

不同溶胶组成对BaLa0．3Fe11．7O19纳米粉末生成过程的影响

利用溶胶-凝胶自燃烧高温合成法制备了稀土La掺杂钡铁氧体BaLa0.3Fe11.7O19纳米粉末.用X射线衍射仪、振动样品磁强计和透射电镜对不同溶胶组成下合成的粉末的结构、磁学性能、粒度及形貌进行了研究.试验表明用氨水调节溶液起始pH值以及加入适量的柠檬酸和乙二醇是合成结构纯净、性能优异的BaLa0.3Fe11.7O19纳米粉末的2个关键步骤.在溶液起始pH值呈弱酸性(7.0左右)、柠檬酸/硝酸盐=3、煅烧温度为850℃,保温1 h的条件下,利用溶胶-凝胶自燃烧高温合成法可以制备出粒径为36nm的磁铅石结构的BaLa0.3Fe11.7O19粉末,其磁学性能优异,比饱和磁化强度可达65.54 A·m2/kg,矫顽力可达433 kA/m.     

低温烧结Bi-CVG铁氧体的微结构与性能研究

利用传统陶瓷工艺制备了Y1.05Bi0.75Ca1.2Fe44V0.6O12铁氧体,并对其低温烧结特性进行了研究。结果表明,选择适当的预烧温度可以有效提高铁氧体的密度;烧结温度对相稳定性和磁性能影响显著。在900℃预烧、1100℃烧结,可获得晶粒大小均匀、结构致密的烧结体,其磁特性为：B=4．84×10^-2T,B=3．76×10^-2T,Hc=364A／m。     

溶胶-凝胶法制备锶铁氧体纳米粉体的研究

掺杂锶铁氧体(SrFe12O19)作为磁性材料和微波材料具有广泛应用.采用以柠檬酸作金属离子络合剂的溶胶-凝胶法合成组份分别为SrTixCoxFe(12-2x)O19,SrNixCoxFe(12-2x)O19,和SrZnxCoxFe(12-2x)O19(x=0～1.5 mol%)的溶胶-凝胶,加热浓缩至自燃,制得铁氧体纳米粉体的先驱粉体,再经900～1100℃烧结制备出铁氧体粉体产物.用XRD研究产物的晶相及其晶粒的平均大小;用TEM和SEM观察粉体形貌.研究结果表明:当Ti/Co共掺时,锶铁氧体的晶相没有变化,相粒平均大小30～50 nm;当Ni/Co或Zn/Co共掺时,锶铁氧体晶相的含量随掺杂量x的增大而减小,并出现Fe3O4晶相和α-Fe2O3晶相杂质;当共掺量为1.5 mol%时,所得粉体均为Fe3O4晶相、晶粒平均尺寸约40 nm的纳米粉体.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Rheology Feature of Simple Metal Melt

The rheology feature of Sb, Bi melt and alloys was studied using coaxial cylinder high-temperature viscometer. The results showed that the curve of torsion-rotational speed for Sb melt presents a linear relation in all measured temperature ranges, whereas for the Bi melt, the curve presents obvious non-Newtonian feature within the low temperature range and at relative high shear stress. The rheology feature of Sb80Bi20 and Sb20Bi80 alloy melts was well correlated with that of Sb and Bi, respectively. It is considered that the rheology behavior of Sb melt plays a crucial role in Sb80Bi20 alloy and that of Bi melt plays a crucial role in Sb20Bi80 alloy.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.