铝合金磷酸阳极化和胶接性能分析

采用磷酸阳极化方法对铝合金试片进行了处理并考察了其粘接性能。阳极化处理使铝合金试片表面产生了微观粗糙的多孔膜，最初形成的孔互不连通，随着阳极化过程的继续，孔与孔之间互相贯通；胶接时胶粘剂能够渗入多孔膜，并在粘接界面上形成过渡层，实现良好的机械啮合。经阳极化处理后，铝合金试片粘接性能显著提高，拉剪强度在粘接副为铝合金时提高了238％，粘接副为铝合金／复合材料时提高了104％，且破坏模式为混合破坏。对粘接副的耐候性进行了考核，在25～70℃时，其拉剪强度保持不变，100℃时拉剪强度为30．25MPa，与常温拉剪强度相比下降了19．2％；粘接副经碱水浸泡后拉剪强度降低，经过100h浸泡后拉剪强度为35．55MPa，降低了8．1％。     

铝合金硫酸阳极氧化对胶接性能的影响

为研究铝合金硫酸阳极氧化对胶接性能的影响,采用了硫酸阳极氧化的方法,对铝合金试片进行了处理,并考察了其胶接性能.阳极氧化处理能扩大微观表面积,并能获得多孔性的活性表面.胶接时胶粘剂能够渗透进入多孔膜,并在粘接界面上形成过渡层,形成良好的机械啮合.结果表明:经阳极氧化处理后,铝合金试片粘接性能显著提高,剪切强度提高71%,剥离强度提高80%.     

低电压下多孔阳极氧化铝膜的制备

选取草酸溶液电解液,采用低压恒压法与二次阳极氧化工艺制备了多孔阳极氧化铝膜(AAO)。借助扫描电镜(SEM),观察了电解液浓度和氧化时间对多孔阳极氧化铝膜的形貌、孔径和孔间距的影响,得到电流随时间的变化曲线。研究了多孔阳极氧化铝膜层厚度与电流密度及氧化时间之间的关系,探讨了多孔阳极氧化铝膜形成机理,优化了阳极氧化制备工艺。结果表明:利用低压恒压法,在氧化电压18 V,氧化时间12 h,氧化液浓度0.6 mol/L时,可制备孔径均匀、高度有序的多孔阳极氧化铝膜。     

硼酸对7050铝合金硼酸-硫酸阳极氧化膜结构及耐蚀性的影响(英文)

通过 AFM、交流阻抗谱及扫描 Kelvin 探针技术,研究硼酸对 7050 铝合金硼酸?硫酸阳极氧化膜结构及耐蚀性的影响。结果表明,在硼酸-硫酸阳极氧化体系中,硼酸不会改变氧化膜阻挡层的结构,但会显著影响氧化膜多孔层的结构形式,进而影响氧化膜的耐蚀性。在 0～8 g/L 的范围内,随着电解液中硼酸含量的增加,氧化膜的多孔层电阻增大,电容减小,表面势正移,孔径缩小,耐蚀性变好。在高于 8 g/L 时,随着硼酸含量的增加,氧化膜的孔隙变大,阻抗变小,电子逸出功降低,耐蚀性变差。     

铝阳极氧化膜在氯化钠溶液中的孔蚀行为(Ⅰ)——氧化膜双层结构与耐孔蚀性能

采用电流回复处理、电化学和化学浸泡等方法研究了铝硫酸阳极氧化膜及膜的双层结构对膜层在NaCl溶液中的孔蚀行为。实验表明:硫酸阳极氧化膜具有较高的耐孔蚀性能,膜中的多孔层起着主要作用。多孔层的厚度与孔径是影响膜层耐孔蚀性能的主要因素,多孔层厚、孔径小,膜层耐孔蚀性能就好;反之就差。     

铝合金在HEDP电解液中的阳极氧化行为及膜层结构EI北大核心CSCD

选用羟基乙叉二膦酸(HEDP)为电解液对1060铝合金进行阳极氧化,分析了其在恒压氧化过程中的电流变化特征;借助FESEM、EDS、XRD等分析了氧化膜的微观结构、化学组成及其演变过程,探讨HEDP阳极氧化膜的生长机制;通过动电位极化曲线评价HEDP阳极氧化处理铝合金的耐蚀性。结果表明:HEDP体系中铝合金阳极氧化膜的形成是一个电化学成长与化学溶解的动态调整过程。HEDP阳极氧化膜与硫酸阳极氧化膜类似,也呈双层结构;外层为蜂窝孔状结构,只是孔径略大;内层为壁垒型结构,但明显更厚;膜层主要由非晶态Al_(2)O_(3)组成,同时多孔层中含有一定量的水合Al_(2)O_(3)。随着氧化时间的延长,孔径和孔隙率会不断增大;氧化30 min时,膜层厚度为4~5μm,表面孔径为110~120 nm,阻挡层厚度约154 nm。HEDP阳极氧化膜大幅提升了1060铝合金的耐蚀性,且膜层厚度相当时,其耐蚀性优于铬酸阳极氧化膜。     

铝阳极氧化膜在氯化钠溶液中的孔蚀行为（I）——氧化膜双层结构与耐孔蚀性能

采用电流回复处理,电化学和化学浸泡等方法研究了铝硫酸阳极氧化膜及膜的双层结构膜层在ＮａＣｌ溶液中的孔蚀行为,实验表明,硫酸阳极氧化膜具有较高的耐孔蚀性能,膜中的多孔层起着主要作用,多孔层的厚度与孔径是影响膜层耐孔蚀性能的主要因素,多孔层厚,孔径小,膜层耐孔蚀性能就好,反之就差。     

电解液成分对铝合金磷酸阳极氧化膜性能的影响

采用磷酸作为基本电解液对2124铝合金进行阳极氧化,研究了电解液成分对氧化膜层性能的影响。研究结果表明,磷酸浓度在10～40 g/L范围内时,随磷酸浓度增加,膜层厚度增加,硬度减小。在磷酸电解液中加入成膜添加剂,可以有效提高膜层的质量。同时,优选出最佳的磷酸复合电解液配方。研究结果对于制备大孔径、高厚度和高硬度的氧化膜有积极意义。     

硼酸钠浓度对镁合金阳极化的影响

采用电压-时间曲线、全浸腐蚀实验、极化曲线法、X射线衍射法（XRD）、扫描电镜（SEM）、能量色散谱仪（EDS）和X射线光电子能谱法（XPS）等方法研究了AZ91D镁合金在含不同浓度四硼酸钠的阳极化溶液中的阳极氧化行为和膜层的成分、结构.结果表明：在文中给定工艺中,AZ91D镁合金的阳极化过程可分为3个阶段：电火花出现之前的致密层生成阶段;少量小电火花出现的多孔层生成阶段;出现较大电火花的多孔膜层稳定生长阶段.阳极氧化过程中,随着阳极氧化溶液Na2B4O7浓度的升高,出现电火花的时间延长,出现电火花时的电压值升高;膜层厚度增加,膜层上的孔径增大.阳极化膜层中主要含有Mg^2＋、O^2-、Si^4＋和B^3＋,主要相结构为MgO、MgSiO3和Mg3B2O6.四硼酸钠浓度对阳极化膜的耐蚀性影响较大,当四硼酸钠浓度为160 g/L时,膜层耐蚀性能最好.     

硼-硫酸-草酸电解液降压阳极氧化疏孔膜层制备及表征

使用铝合金在硼-硫酸-草酸电解液中阳极氧化制备有序多孔层。初步探讨了恒流和降压阳极氧化过程膜层生长机理,采用扫描电镜(SEM)观察膜层微观形貌,结合电化学阻抗和动电位极化曲线研究不同阳极化工艺制备膜层试样在3.5%NaCl溶液中的耐蚀行为。结果表明,采用三段变压方式制备的阳极氧化膜表面孔密度降低,孔壁增厚,孔径为10~13 nm。疏孔膜层的电化学行为表明孔壁及膜层厚度增大能提高试样电荷传递电阻和耐蚀性能。     

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.     

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.