等原子比NiAl多晶合金的超塑性行为

研究了等原子比ＮｉＡｌ多晶材料在不同的温度及应变速率条件下的拉伸行为.结果表明,在温度为１１００℃及应变速率为１．６７×１０－４－１．６７×１０－２ ｓ－１条件下,挤压态等原子比 ＮｉＡｌ多品材料表现出超塑性行为,拉伸延伸率均超过２００％,最大达到２１０％,且应变速率敏感指数均大于 ０．３．对其超塑性的变形机制进行了初步探索     

基于人工神经网络的铸态904L超级奥氏体不锈钢本构关系

以铸态904L超级奥氏体不锈钢热压缩实验数据为样本,采用BP人工神经网络建立了以变形温度、应变速率和应变量为输入层,流变应力为输出层的热变形本构模型。结果表明,BP网络预报的流变应力值与实验值比较吻合,平均绝对误差值为2.06%。该模型能够准确反映铸态904L超级奥氏体不锈钢的高温流变行为,为合理控制热轧工艺参数提供一定参考。     

Fe—5Ni合金奥氏体高温变形行为

在温度９７３－１３７３Ｋ，形变速率２×１０＾－５－１．５×１０＾－２ｓ＾－１的试验条件下，研究了Ｆｅ－５Ｎｉ合金奥氏体的高温拉伸变形行为。结果表明：高温变形时峰值应力σｐ与温度Ｔ和形变ε之间符合五式关系：Ｚ＝εｅｘｐ（Ｑ／ＲＴ）＝Ａ（ｓｉｎｈ（ασｐ））＾ｍ。高应变速率区的激活能Ｑ为３１４ｋＪ／ｍｏｌ，与Ｆｅ的自扩散激活能Ｑｓｄ相当，变形由空位扩散所控制；而低应变速率区的Ｑ为２０２ｋＪ／ｍｏｌ，约     

高强度奥氏体不锈钢的热变形行为及其热加工图

从工业生产的不锈钢大型锻件上取样,在应变速率0.01～10s-1、变形温度850～1250℃条件下采用Gleeble3500热模拟试验机进行了压缩热变形试验,研究了一种高强度奥氏体不锈钢热变形力学行为和再结晶规律,测得热变形激活能为455kJmol,并列出了这种高强度奥氏体不锈钢的热变形方程ε=4.173·1016[sinh(α·σp)]4.06exp-455000RT。基于动态材料模型建立了其在常见形变量之下的热加工图(ProcessingMap)。试验结果说明,该奥氏体不锈钢具有较高的动态再结晶温度,在1150℃变形能量消耗效率达到最大值0.4。     

00Cr25Ni7M04N超级双相不锈钢的热变形行为

采用Gleeble-3800热模拟机研究了铸态00Cr25Ni7:Mo4N双相不锈钢在应变速率为0.1s-1～10s-1,变形温度为1000～1200℃下的热变形行为,分析了流变应力与应变速率以及变形温度之间的关系.结果发现在同一应变速率下随温度的升高峰值应力值σp减小;在同一温度下随着应变速率的减小峰值应力值σp也减小,并获得了在热变形条件下该双相不锈钢的热变形方程以及其它热变形参数,计算出该双相不锈钢的热变形激活能为433kJ/mol.     

00Cr25Ni7Mo4N超级双相不锈钢的热变形行为

采用Gleeble．3800热模拟机研究了铸态00Cr25Ni7Mo4N双相不锈钢在应变速率为0．1s^-1。10s^-1,变形温度为1000,1200℃下的热变形行为,分析了流变应力与应变速率以及变形温度之间的关系。结果发现在同一应变速率下随温度的升高峰值应力值σp。减小;在同一温度下随着应变速率的减小峰值应力值σp也减小,并获得了在热变形条件下该双相不锈钢的热变形方程以及其它热变形参数,计算出该双相不锈钢的热变形激活能为433kJ／mol。     

304L不锈钢高温变形组织的演化

采用Gleeble-1500D热/力学模拟试验机对304 L不锈钢铸态及锻态试样进行了热压缩试验研究,工艺参数为：变形温度950℃～1 150℃、变形量0.7,变形速率0.1s-1。结果表明：铸态的峰值应力低于锻态的峰值应力,铸态组织的动态再结晶明显迟于锻态组织;铸态及锻态304L不锈钢流变应力随着温度的升高而降低;随着变形温度的升高,动态再结晶百分数增加,再结晶组织增多并趋于完全。     

共晶NiAl—9Mo合金的超塑性行为

研究了共晶 ＮｉＡｌ－９Ｍｏ合金的超塑性行为及其变形机制．该合金的微观组织由 ＮｉＡｌ以及 ＮｉＡｌ和α－Ｍｏ共晶体组成．在 １３２３－１３７３ Ｋ温度区间,以 ５.５５×１０－５－１．１１×１０－４ ｓ－１的应变速率拉伸变形时,表现出超塑性行为,最大延伸率达到 １８０％,应变速率敏感性指数达到 ０．５６．超塑性的变形机制为初生 ＮｉＡｌ基体的晶界滑动,断裂起源于超塑性变形过程中产生的孔洞．     

S32654超级奥氏体不锈钢压缩热变形中流动行为的本构模型

利用Gleeble-3008热模拟机研究了S32654超级奥氏体不锈钢在950~1 250℃、应变速率为0.001~10 s~(-1)条件下的热压缩变形行为,并建立该材料的热变形本构模型。结果表明:变形温度和应变速率对S32654超级奥氏体不锈钢的流变应力影响显著;流变应力随温度升高而减小,随应变速率增加而增大。温度高于1 150℃、应变速率小于0.1 s~(-1)时钢的应力曲线较平稳,在10 s~(-1)的高应变速率时流变曲线出现动态软化现象。S32654超级奥氏体不锈钢的热变形本构模型预测值与实验值吻合较好。     

铸态双相不锈钢高应变率下热变形流变应力预测模型

采用热压缩试验研究了22Cr铸态双相不锈钢在变形温度为1000~1200℃,应变速率为1~50 s-1条件下的热变形行为。为了准确的表征双相不锈钢热变形过程中的力学行为,修正了热压缩过程中摩擦和变形热效应引起的流变应力误差。在此基础上建立了双相不锈钢的流变应力预测模型。该模型通过考虑应变对材料常数(α、n、Q和ln A)的影响,进一步获得了双相不锈钢热变形过程中流变应力与变形温度、应变速率和应变的关系。结果表明:所建立的模型能较好的预测双相不锈钢的热变形行为,预测值与实验值的相关系数为0.995,平均相对误差为4.48%。     

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.