原位增强相(TiB2+Al3Ti)形成的热力学分析

采用混合盐法制备了(TiB2 Al3Ti)/Al-4.5Cu原位复合材料,对增强相的形成热力学进行了分析,并采用差热分析法(DTA)对混合盐反应体系的热量变化进行分析.结果表明,Al-Ti-B三元体系中,TiB2的形成能力最强.但因[Ti]实际相对过剩,与Al结合形成Al3Ti,最终制得的复合材料中增强相为TiB2和Al3Ti;差热分析表明了混合盐体系加入到Al-4.5Cu熔体中,可以发生原位反应,形成增强相.原位反应的开始温度为900 ℃,结束温度为1 032 ℃.     

混杂增强相(Al3Ti-TiB2-SiC)的形成热力学分析

对利用原位反应与高剪切液态搅拌复合专利技术制备的Al3Ti-TiB2-SiC/Al-13%Si复合材料的增强相的形成热力学进行了理论计算和分析,并采用差热分析法(DTA)进行了试验验证.研究表明:(1)Al-Ti-B体系加入到Al-13%Si熔体中可发生原位反应,形成增强相,原位反应的开始温度为905.3℃,结束温度为1 061.23℃;(2)Al-Ti-B体系加入到Al-13%Si熔体中,制备颗粒增强Al-13%Si复合材料的增强相为TiB2和Al3Ti,但TiB2形成能力最强.     

反应热压（A12O3＋TiB2＋A13Ti）／Al复合材料的组织形成机制

采用B或B2O3、TiO2和Al粉反应热压制备了原位(Al2O3 TiB2 Al3Ti)／Al复合材料，采用光学显徽镜、扫描电镜和透射电镜分析了原位复合材料的显微组织。热压状态下，反应生成相Al3Ti呈大块不规则形状，尺寸约几十微米；Al2O3和TiB2为细小弥散质点，TEM分析发现TiB2颗粒呈六边形，而Al2O3颗粒呈等轴状。在以Al粉、TiO2粉和B粉为原料制备的复合材料中，除反应生成了大块的Al3Ti相外，还有细小针状Al3Ti相沉淀析出，且呈弥散分布。热挤压后大块的Al3Ti被破碎成细小弥散质点。Al2O3在TiO2和B2O3粉末表面生成；TiB2在B或B2O3粉表面形成，因而均呈弥散分布，且尺寸细小。自TiO2中还原出的Ti溶入液态Al中形成A13Ti时，Ti可在液态Al中长距离扩散，因而Al3Ti呈大块不规则状。     

放电等离子合成Ti3AlC2-TiB2复合材料的相形成研究

采用放电等离子烧结工艺,以Ti,Al,B4C,TiC为原料制备Ti3AlC2／TiB2复合材料。通过X射线衍射分析了从600℃到1300℃Ti3AlC2／TiB2系统反应过程的相形成规律。用扫描电镜观察了不同温度下试样的显微组织演变。结果表明,在900℃之前,主要的反应是Ti和Al反应生成Ti—Al金属间化合物,900℃之后,Ti—Al金属间化合物与TiC逐渐生成Ti3AlC2和TiB2相,形成致密Ti3AlC2／TiB2复合材料。     

原位反应合成TiB2的生长行为

研究了(K2TiF6 KBF4)/A356混合盐反应体系中原位合成TiB2增强相的热力学行为及其晶体生长行为.结果表明,原位反应温度明显影响反应体系最终产物及TiB2增强相的形貌.(K2TiF6 KBF4)/A356体系原位反应温度应控制在850 ℃为宜,由此可以完全消除TiAl3脆性相,并生成六棱粒状TiB2增强相颗粒,提高增强相强化效果.     

AlTi5B1对亚共晶铝硅合金的组织和性能的影响

研究了AlTi5B1的加入量对亚共晶铝硅合金微观组织和力学性能的影响.结果表明:A1Ti5B1的加入量对合金的抗拉强度影响较大,并在Ti含量为0.06％时,抗拉强度达到最大值；对伸长率的影响和对抗拉强度的影响是一致的；对合金的硬度影响较小.加入AlTi5B1细化处理后,TiB2粒子和三元相Ti(Al1-x,Six)3数量增加,是α-Al相的有效形核核心,起主要的细化作用；第二相(Fe相,AlCu相)的形貌及分布发生了变化,强化了晶界,减弱了Fe相的有害作用.     

热压烧结反应生成TiB／Ti-4．0Fe-7．3Mo复合材料的组织与性能

采用机械合金化(MA)的方法将B和FeMo粉末与金属Ti的粉末混合均匀，球磨10h后，真空热压烧结制备原位生成TiB增强Ti-4．0Fe-7．3Mo复合材料。在金相显微镜(OM)下观察，复合材料由TiB增强区与不含TiB的基体所组成。TEM研究表明：增强区足由反应生成的TiB增强的α和β-Ti2相共同组成，在α和β-Ti相交界处分布的TiB不仅尺寸较人，而且数量也较两相内部的TiB多。在α钛中观察到少量的平行于α相板条的特殊TiB的存在。反应生成的TiB呈截面为六边形的针状，与基体的界面清洁、平直匹配良好。复合材料的三点弯曲强度和杨氏模量均随反应生成TiB体积含量的增加而降低。     

放电等离子原位烧结制备TiC＋TiB／Ti复合材料

采用放电等离子烧结（SPS），通过Ti与B4C之间的原位反应合成TiC＋TiB／Ti复合材料。首先通过热力学计算判断可能发生的反应，利用x射线衍射（XRD）、扫描电镜（SEM）对球磨混合粉以及烧结后材料的相组成和显微组织进行了研究，测定材料的相对密度和硬度，并探讨了Ti与B4C采用放电等离子烧结制备TiC＋TiB／Ti复合材料的致密化过程和反应机理。结果表明，采用SPS技术，在1150℃保温5min的条件下，Ti与B4C能同步完成反应、烧结、致密化，生成TiC＋TiB／Ti复合材料，并且原位生成的增强相分布均匀且细小。     

Ti6Al4V表面激光熔覆NiCrBSi+B4C涂层的组织结构

选用NiCrBSi及2％民C混粉在Ti6Al4V合金表面进行激光熔覆处理，使基体中的Ti和B4C发生化学反应原位生成TiC、TiB2硬质增强相，制备出TiC与TiB2等增强相增强钛基复合材料涂层。综合运用XRD、SEM、EPMA和TEM等分析手段研究了优化熔覆工艺条件下的NiCrBSi＋B4C激光熔覆层的组织结构与相组成，并对复合涂层进行了硬度测试，结果表明：NiCrBSi＋2％B4C熔覆层的微观组织是在γ—Ni和Ni3Ti＋Ni3B共晶的基体上均匀分布着TiB2、TiC、CrB等相的多元组织，激光熔覆层的硬度比Ti6Al4V基体硬度提高到3～4倍。     

原位TiB2(p)/Fe复合材料的制备及其显微组织

利用Fe—Ti5—B熔体反应制备了TiB2颗粒增强铁基复合材料，研究了该材料的显微组织。热力学分析表明，Fe-Ti-B熔体具有反应生成TiB2的可能性。试验结果表明，TiB2颗粒均匀分布于α—Fe晶粒中，晶内TiB2粒子平均间距大于晶界。TiB2粒子尺寸大多为1-6μm，形状大多为接近等轴的多面体。     

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.     

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.     

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.