温度对Zr—4合金低周疲劳性能的影响

研究了室温和４００℃去应力退火状态Ｚｒ－４合金对称拉－压低周疲劳行为。建立了循环和单调加载方式下Ｚｒ－４合金应力－应变曲线方程和循环应变幅－疲劳寿命之间的关系；分析了温度对Ｚｒ－４合金变形行为和疲劳性能的影响；讨论了高温疲劳寿命预测方法；根据疲劳断口ＳＥＭ观察结果，分析了Ｚｒ－４合金在室温和４００℃疲劳断裂方式的异同。结果表明，Ｚｒ—４合金室温下的循环应力－应变曲线表现为循环硬化，而４００℃下表现为循环软化；室温和４００℃下的循环应变幅－疲劳寿命关系分别为△εｐ·Ｎｆ０．７６６８＝４８．９４，△εｐ·Ｎｆ０．３６８９＝４．９８．     

Zr-4合金双轴疲劳行为及其微观变形机理Ⅰ.双轴疲劳变形行为

研究了不同主应变比比例加载和不同相位角非比例加载条件下Ｚｒ－４合金双轴疲劳行为。结果表明：双轴比例和非比例循环变形过程中,在Ｍｉｓｅｓ循环等效应力响应－循环周次曲线上,Ｚｒ－４均表现为循环初始硬化,随后逐渐软化特征。Ｍｉｓｅｓ循环等效应力－应变曲线均位于单调曲线的上方,表现为循环硬化特征。进一步研究表明：非比例加载过程中合金的循环强化程度高于相同等效应变下的比例加载,表现为非比例附加强化现象。当主     

Zr—Mn—Ni系Laves相贮氢合金中的Zr—Ni相及其晶体结构研究

采用Ｘ射线粉末衍射和Ｒｉｅｔｖｅｌｄ全谱拟事分析,详细地研究了Ｚｒ（Ｍｎ１－ｘＮｉｘ）２（ｘ＝０．４０～０．７５）三元Ｌａｖｅｓ相贮氢合金中形成Ｚｒ－Ｎｉ相的类型及其晶体结构。实验结果表明：Ｚｒ－Ｍｎ－Ｎｉ合金中出现的Ｚ４－Ｍｎ－Ｎｉ合金中出现的Ｚｒ－Ｎｉ相包括ＺｒＮｉ、Ｚｒ９Ｎｉ１１和Ｚｒ７Ｎｉ１０３类,ｒ－Ｎｉ相类型与合金中的Ｎｉ含量有关。其中,ＺｒＮｉ相在ｘ＝０．４０～０．５０范围内出现,Ｚ     

电厂凝汽器用铜—钛复合管的开发

研究了超轻Ｍｇ－８Ｌｉ合金的高温超塑力学性能，实验表明，在变形温度５７３Ｋ，应为速率５×１０＾４ｓ＾－１的条件下可获得最大延伸率９６０％，从对数真应力－真应变速率曲线得到的应变速率敏感性指数为０．６４，该值表明在Ｍｇ－８Ｌｉ合金中发生了晶界滑移为主要变形机制的高温变形过程。     

ZrMn0.9—xVxNi1.1（x=0.1—0.8）Laves相贮氢合金的电化学性能

研究了ＡＢ２型锆基Ｌａｖｅｓ相贮氢合金ＺｒＭｎ０．９－ｘＶｘＮｉ１．１（ｘ＝０．１～０．８）的晶体结构及其电化学性能。研究表明，ＺｒＭｎＶＮｉ合金为多相组织，当Ｍｎ含量较高时，合金的主相为Ｃ１５型Ｌａｖｅｓ相结构；随着Ｖ含量增加，合金中Ｃ１４型Ｌａｖｅｓ相的含量逐渐增加；合金的主相结构与电子浓度有关。Ｍｎ、Ｖ含量影响Ｌａｖｅｓ相合金中的不同类型四面体间隙数目及合金热力学和电化学性能。当合金中的Ｖ／（Ｍｎ＋Ｖ）比率在２／９～４／９范围内，合金表现出较好的综合电化学性能。ＺｒＭｎ０．５Ｖ０．４Ｎｉ１．１合金的最高容量为３４２ｍＡｈ／ｇ，高倍率放电能力为Ｃ２００／（Ｃ２００＋Ｃ５０）＝７５％，经１００次１００％ＤＯＤ充放电循环后，容量保持率为８５％左右。     

锆—4合金的时间相关低周疲劳

研究了锆－４合金在不同应变速率下的低周疲劳和带应变保持时间相关低周疲劳行为。结果表明：在不同加载方式下，锆－４合金均表现为循环硬化，应变保持和应变速率降低均进一步提高环孢和应力。应变保持降低材料的疲劳寿命，特别是在高应变幅区域。随着应变速率降低、材料疲劳寿命降低。疲劳变形亚结构观察表明：锆－４合金时间相关疲劳过程中以｛１０１↑－０｝柱面滑移和晶界滑移方式变形。     

Zr及Zr—4合金的循环耗散能,分形维数与疲劳寿命的关系

测定了纯Ｚｒ及Ｚｒ－４合金在室温和４００℃下低周疲劳寿命曲线,分别选用循环塑性耗散应变能和疲劳断口表面分形维数作为疲劳损伤参量,根据Ｚｒ及Ｚｒ－４合金表现为循环硬化,饱和、再软化三阶段的特征,建立了不同变形阶段的累积塑性耗散应变能表达式。结果表明,不同塑性应变幅下循环塑性耗散应变能与疲劳寿命之间满足指数关系。疲劳断口表面分形分析表明：分形维数与疲劳寿命之间也满足指数关系,循环塑性耗散能、分形维数与     

钛合金低周疲劳性能研究

采用轴向应变控制的方法，在Ｉｎｓｔｒｏｎ－１３４３型万能疲劳试验机上测定了ＴＡ５钛合金的低周疲劳性能数据，研究了在循环载荷下该材料的应变与寿命的关系，初步预测了ＴＡ５钛合金的低周疲劳寿命。结果表明，塑性变形是造成ＴＡ５合金疲劳损伤的根本原因；通过试验求得的该材料的应变与寿命关系曲线其对数方程为一直线ε_ｔ＝０．０２８８Ｎ~（－０．１９９７）（其中相关系数ｒ＝０．９９１４．标准差Ｓ＝０．２１５３）；ＴＡ５钛合金具有循环软化的特性；其低周疲劳断口具有明显的挤压条纹特征。     

氢对BT8M合金的组织状态和机械性能的影响

采用为生产紧固件按工业纯提供的热轧ＢＴ８Ｍ棒材（合金成分： ５．１％Ａｌ，０．９６％Ｚｒ，４．１１％Ｍｏ， ０．１８％Ｓｉ和１．０８％Ｓｎ；成分含量均为重量百分比）进行了试验。在试验设备中于６５０℃温度下和在０．００３％－０．７％浓度之内实现了定量渗氢．在由氢诱发的高温β－相冷却进程中，为了防止复合相转变，选择了低温氢化过程。在　ＰＯＨ－４衍射器中，实现了Ｘ射线分析．在Ｈｅｏ　ｏｒ－２型显微镜下进行了金相研究。而标准的机械试验在　１０／９０设备上和ＭＫ－３０Ａ冲击试验机上进行。 用淬火试验方法确定…     

锆－4合金的时间相关低周疲劳

研究了锆－４合金在不同应变速率下的低周疲劳和带应变保持时间相关低周疲劳行为。结果表明：在不同加载方式下，锆－４合金均表现为循环硬化，应变保持和应变速率降低均进一步提高循环饱和应力。应变保持降低材料的疲劳寿命，特别是在高应变幅区域。随着应变速率降低，材料疲劳寿命降低。疲劳变形亚结构观察表明：锆－４合金时间相关疲劳过程中以柱面滑移和晶界滑移方式变形。     

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.     

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.