磨球直径和添加剂对行星球磨行为的影响

借助制备Fe、WC微粉过程中不同工艺条件对比，分析了磨球尺寸和球磨添加剂对行星球磨行为的影响。结果表明，磨球大小与粉料的细化效率之间存在一定的对应关系，磨球数量和添加剂性质会改变物料的工作状态。     

高能球磨法制备SiC/Al复合粉末的工艺研究

采用高能球磨技术制备SiC和Al的复合粉末,研究了球磨时间、过程控制剂(PCA)、球料比以及SiC与Al混粉质量比对复合粉末粒度和包覆效果的影响。结果表明,复合粉末平均粒径的大小与PCA、混粉比、球磨时间和球料比有关,其影响程度依次为:PCA>混粉比>时间>球料比;复合粉末的粒径大小随着球磨时间、PCA和球料比的增加而显著减小,而随着混粉质量比的增加呈现先减后增的趋势。混粉质量比为3:7的复合粉末平均粒径达到最小值;球磨时间为9h、PCA添加量为1.5%、球料比为12:1和Al与SiC混粉质量比为3:7时,能制备出颗粒细小、包覆效果好的优质复合粉末。     

机械合金化制备金属间化合物MoSi2

以Si粉和Mo粉为原料采用机械合金化的方法制备了金属间化合物MoSi2。研究了球磨过程中球磨时间、球料比、转速及不同球磨机类型对机械合金化产物的影响。利用SEM观察粉末表面形貌及颗粒大小，利用XRD测定物相结构。研究结果表明，当球磨机提供的能量达到相变所需的能量时，粉末中有MoSi2相生成。通过XRD分析可以看出，随着球磨时间的延长，合金化程度逐渐提高：球磨转速的提高有助于生成MoSi2：较高的球料比可以使生成MoSi2的时间提前。在机械球磨过程中，粉末的颗粒尺寸经历了一个由较粗且不规则、不均匀粉末向细小、均匀、接近球形粉末，然后团聚增大的转化过程。此外，还研究了助磨剂对合金化产物的影响，结果表明助磨剂的加入并不能促进MoSi2的生成，但可以对颗粒的细化起到一定作用。     

机械球磨法制备纳米WO3粉及球磨参数影响

采用机械球磨法制备纳米WO3陶瓷粉末,系统研究了球磨参数对粉末粒度的影响。结果表明,机械球磨法可以制取纯度较高的WO3细粉;球磨时间和球料比以颗粒尺寸趋于稳定的范围为佳,盲目延长时间、增大球料比起不到细化作用,相反会增加WC杂质的引入。     

湿法球磨工艺参数对硅酸锆平均粒度的影响

对锆英砂湿法球磨加工中存在的问题进行了概述和分析,研究了湿法球磨中的球磨机转速、研磨时间、浆料浓度、填充率、球料比等工艺参数对硅酸锆的平均粒度的影响规律。研究结果表明,增加球磨机的转速,延长球磨时间,都会使研磨出的硅酸锆粒度变得更小,且硅酸锆平均粒度变化曲线都呈初期变化大,超过拐点后变化减缓的趋势。填充率和浆料浓度对硅酸锆平均粒度的影响类似,随着填充率或浆料浓度的不断增加,研磨出来的硅酸锆粒度越小,但总体上下降幅度不大,其变化幅度的差别主要来自于罐中水和空气的比例不同。球料比对硅酸锆的平均粒度影响显著,当球料比在2∶1到6∶1的范围内变化时,随着球料比增大,研磨出来的硅酸锆的平均粒度由6.55μm下降到1.82μm。     

Al-Zr复合粉末高能球磨工艺参数研究

为获得制备铝基复合材料所需的亚微米级Al3Zr金属间化合物,采用高能行星球磨设备制备了Al-Zr复合粉末,并采用X射线衍射仪和扫描电镜等技术研究了球磨工艺参数(球磨时间、球料比和转速)对复合粉末微观组织的影响。结果表明:随高能行星球磨能量的增加(球磨时间、球料比和球磨速度),Al-Zr复合粉末的衍射峰逐渐宽化,峰强度减弱,晶粒细化甚至出现非晶组织。经转速320r/min,球料比30:1,球磨50h后Al-Zr复合粉末中仍未发现有金属间化合物生成,即Al、Zr仍以单质和固溶体形式存在,故欲制备亚微米级甚至纳米级的Al3Zr相仍需在后续处理中对其进行热处理。     

球料比对高能球磨固态还原燃烧反应的影响

在所研究的 Al/Cu O和 Si/Cu O体系中 ,不同球磨强度下 ,随球料比增大 ,燃烧点火时间存在一极小值。说明球磨固态燃烧反应的点火时间的长短取决于球磨粉末中已经发生部分反应的产物所占的比例和同时发生反应的活性位置数目。提出一新的、具有广泛适应性的球磨参量—占空比 VR,修正了传统采用球料比 CR在描述球磨强度与球磨燃烧反应点火时间时所存在的不足     

机械合金化制备金属间化合物MoSi2

以Si粉和Mo粉为原料采用机械合金化的方法制备了金属间化合物MoSi2.研究了球磨过程中球磨时间、球料比、转速及不同球磨机类型对机械合金化产物的影响.利用SEM观察粉末表面形貌及颗粒大小,利用XRD测定物相结构.研究结果表明,当球磨机提供的能量达到相变所需的能量时,粉末中有MoSi2相生成.通过XRD分析可以看出,随着球磨时间的延长,合金化程度逐渐提高;球磨转速的提高有助于生成MoSi2;较高的球料比可以使生成MoSi2的时间提前.在机械球磨过程中,粉末的颗粒尺寸经历了一个由较粗且不规则、不均匀粉末向细小、均匀、接近球形粉末,然后团聚增大的转化过程.此外,还研究了助磨剂对合金化产物的影响,结果表明助磨剂的加入并不能促进MoSi2的生成,但可以对颗粒的细化起到一定作用.     

球磨参数对机械合金化制备碳化硅粉体的影响

通过热力学计算分析石英与石墨反应的可行性。研究了机械合金化石英与石墨混合粉末的过程中,球磨工艺（球磨时间、球料比）对机械合金化过程的影响。试验结果表明,采用球料比50：1,球磨机转速为300r／min,球磨时间为72h时,体系提供了足够的能量生成碳化硅。     

TiH2粉末的高能行星球磨及超细晶钛烧结

研究TiH 2粉末的高能行星球磨规律,然后使用制备出的球磨粉末开展压制?真空烧结,评价烧结样品的显微组织特征。结果表明,TiH 2粉末的高能球磨可划分为3个基本阶段：球磨初期粉末粒度迅速细化;球磨中期粉末粒度逐步趋向最小极限尺寸,同时粉末粒径的均匀性和分布集中程度明显改善;在球磨的后期,粉末粒径又会发生粗化现象。因此,TiH2粉末的高能行星球磨存在一组最佳的工艺参数。高能球磨会改变TiH2粉末的脱氢特征温度,且粉体的D 50越小,特征温度下降幅度越大,与原料粉末相比,最大差值达83℃。对烧结样品的显微组织分析显示,通过由球磨TiH 2粉末所获得的烧结钛合金的晶粒度得到了显著地细化;当采用优化的工艺开展球磨TiH 2粉末制备时,通过压制和真空烧结可获得平均晶粒度在5μm以下的超细晶钛。     

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.     

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.     

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.     

Formulas of Tension of Continuous Rolling Process

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.