NiAl—28Cr—5Mo—1Hf多相金属间化合物的显微组织及力学性能研究

研究了铸造和ＨＩＰ处理ＮｉＡｌ－２８Ｃｒ－５Ｍｏ－１Ｈｆ（原子分数,％,下）金属间化合物的显微组织,铸造合金是由ＮｉＡｌ,Ｃｒ（Ｍｏ）和Ｎｉ２ＡｌＨｆ相组成,经１２５０℃,２００ＭＰａ,４．５ｈＨＩＰ处理后。     

添加少量Ni,Ti,C对溅射钨涂层氧化行为的影响

葡萄牙的科研人员采用反应磁控溅射工艺进行研究,具体工艺多数为：功率密度１０Ｗ／ｃｍ２,负偏压为７０Ｖ,靶材分别用Ｗ、Ｗ－１０％Ｔｉ、Ｗ－１０％Ｎｉ（质量百分比）,ＣＨ４／Ａｒ分压比为１／５,真空室压力为１０－４Ｐａ．涂前基体表面用离子轰击清洗．开始时,表面加热到４５０℃,然后用Ａｒ~＋轰击８ｍｉｎ（离子枪在２０Ａ,４０Ｖ下调节,基体偏压为－１２０Ｖ）,沉积时间选择在涂层厚度达到４μｍ为止．然后对获得的Ｗ－Ｃ－Ｍ（Ｍ＝Ｎｉ,Ｔｉ）涂层的化学成分、结构、形貌及抗氧化性能进行了研究． 结果表明,Ｗ－Ｃ－…     

用机械合金化方法制备Ni—Al系金属间化合物

用球磨机分别对Ｎｉ－５０ａｔ．－％Ａｌ和Ｎｉ－２５ａｔ．－％Ａｌ混合粉末进行机械合金化，并对Ｎｉ３Ａｌ预合金粉末进行高能球磨，观察了粉末的金相组织，测定了粉末的硬度、平均直径和晶粒尺寸，并作了ＸＲＤ物相分析。结果表明，经３ｈ研磨，Ｎｉ－５０ａｔ．－％Ａｌ混合粉末变成ＮｉＡｌ金属间化合物，其晶粒直径约５ｎｍ；经５ｈ机械球磨，Ｎｉ－２５ａｔ．－％Ａｌ混合粉末成为无序的亚稳定Ｎｉ固溶体，而Ｎｉ３Ａｌ预合     

Ni3Al＋Ni7Hf2共晶合金的微观结构及凝固行为研究

利用金相、扫描电镜、透射电镜观察了Ｎｉ３Ａｌ＋Ｎｉ７Ｈｆ２共晶合金的微观组织结构,并利用高梯度定向凝固技术研究了该合金的凝固行为：Ｎｉ－５．８Ａｌ－３２Ｈｆ Ｎｉ３Ａｌ＋Ｎｉ７Ｈｆ２共晶组成,是Ｎｉ３Ａｌ／Ｎｉ７Ｈｆ２共晶复合材料的合适成分。由于不平衡凝固,有害相β－ＮｉＡｌ与金属间化合物Ｎｉ７Ｈｆ２以共晶体的形式存共晶胞间,在一定的温度梯度下,可以通过降低生长速度的方式予以消除。Ｎｉ－５．８Ａｌ     

两种不同涂层的Ti纤维增强TiAl基复合材料

研究了涂覆单一涂层Ｙ２Ｏ３或Ａｌ２Ｏ３的Ｔｉ纤维增强γＴｉＡｌ基复合材料的界面和性能。动用物理气相沉只法在Ｔｉ比例有面涂覆Ｙ２Ｏ３或Ａｌ２Ｏ３涂层后，然后用类似箔叠法制得了Ｔｉ－Ｙ２Ｏ３／γＴｉＡｌ和Ｔｉ－Ａｌ２Ｏ３／γ－ＴｉＡｌ复合材料，复合材料的弯曲强度从４４９ＭＰａ提高到５６２ＭＰａ（Ｔｉ－Ｙ２Ｏ３／γ－ＴｉＡｌ）或５７３ＭＰａ（Ｔｉ－Ａｌ２Ｏ３／γＴｉＡｌ）而且高于纯Ｔｉ纤维增强了ＴｉＡｌ     

NiAl和Ni3Al双相合金的超塑性变形

研究了ＮｉＡｌ和Ｎｉ３Ａｌ双相合金在高温超塑性变形行为．结果表明：该合金在９７５至１０２５℃的温度范围及应变速率为１５２×１０（－４）ｓ（－１）时，表现出超塑性变形行为；１０００℃时最大拉伸延伸率为１４９％，此时对应的应力敏感指数为０．３７５．该合金的超塑性形变可用经验公式ε＝Ａσ（２．６７）ｅｘｐ（－３０３０００／ＲＴ）来表示。对拉伸后试样的金相和ＴＥＭ研究表明，合金中ＮｉＡｌ和Ｎｉ３Ａｌ两相在高温能够较好地协同形变，超塑性是由变形过程中发生的连续回复与再结晶过程来实现的．     

离子注Mg的β－NiAl涂层的氧化行为

表面扩散渗铝形成的β－ＮｉＡｌ涂层表面注入Ｍｇ＋１×１０１７／ｃｍ２后，在１０００℃空气中恒温氧化２５ｈ，涂层的氧化增重速率有所增加，这是由于注Ｍｇ的β—ＮｉＡｌ涂层表面形成了Ａｌ２Ｏ３氧化物“瘤”，长时间氧化后氧化物“瘤”周围及“瘤”本身发生开裂，引起涂层内氧化。     

Ni_3Al－Mo复合材料氧化层的结构分析

分析了Ｎｉ_３Ａｌ－Ｍｏ复合材料７００～１０００℃氧化后的氧化层结构。结果发现，氧化层主要由ＮｉＯ、ＭＯＯ２、ＮｉＡｌ２Ｏ４等组成，１０００℃氧化后的氧化层表面仅生成ＮｉＯ薄膜，Ｍｏ纤维对Ｎｉ３Ａｌ－Ｍｏ复合材料的氧化层结构影响很大，ＭｏＯ２被氧化成挥发性很强的ＭｏＯ_３．破坏了氧化膜的连续性，加快了氧化速度，７００℃氧化后，氧化层与基体的界面较光滑，而１０００℃氧化后的氧化层与基体间呈非光滑界面特征。     

高压原位合成高致密TiCp／Ni3Al复合材料

采用高温高压（１．５－６．５Ｇａ，１０７３－１４７３Ｋ）方法，由Ｔｉ，Ｃ，Ｎｉ，Ａｌ四种元素娄末原料原位合成了ＴｉＣ颗粒增强Ｎｉ３Ａｌ金属间化合物基复合材料，其密度大于９８％理论值。其中ＴｉＣ颗业尺寸为纳米级，并讨论了ＴｉＣ晶粒尺寸与合成压力的关系，及对复合材料显微硬度的影响。     

应力对Ni3Al合金表面氧化膜成分的影响

研究了Ｎｉ－２３Ａｌ－０．５Ｚｒ－０．１Ｂ和Ｎｉ－１７Ａｌ－８Ｃｒ－０．５Ｚｒ－０．１Ｂ（ａｔ．－％）在应力作用下表面氧化成分的变化。结果表明，在拉应力作用下氧化膜中的Ｎｉ含量明显增加。分析和计算发现由于Ｎｉ和Ａｌ具有不同的氧化体积膨胀，在拉应力作用下Ｎｉ在氧化表层的富集可以减小氧化表面的弹性形变能，降低体系自由能。     

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.