聚苯胺/改性石墨复合材料的电化学制备及其防腐蚀性能研究

采用恒电流法、恒电流阶跃电流法、循环伏安法及自聚合法等4种方法将聚苯胺(PANI)原位沉积在自制的改性石墨(MGE)上,制备出聚苯胺/改性石墨复合材料(PANI/MGE)。利用扫描电镜和红外光谱对PANI/MGE的微观形貌和分子结构进行了表征,利用电化学阻抗谱研究了不同聚合方法所得复合材料的防腐蚀性能。结果表明,4种聚合方法所得复合材料微观形貌与聚合前的改性石墨相似,都呈现平面的片层结构,没有聚合物团簇聚集现象产生。4种聚合方法均能成功实现聚苯胺的原位沉积,聚苯胺与改性石墨之间存在较强的相互作用,且以恒电流阶跃所得复合材料中两者的相互作用最强。5种不同涂层中,恒电流阶跃聚合所得涂层的防腐蚀性能最好,稳定的自腐蚀电位及涂层阻抗最高;循环伏安聚合及恒电流聚合所得两种复合涂层的阻抗及自腐蚀电位均随时间的延长而逐渐下降,涂层很快失效。     

鳞片石墨对镁合金表面聚苯胺环氧涂层防护性能的影响

目的 针对聚苯胺环氧涂层物理屏蔽性能欠佳的问题,通过引入具有片层结构的鳞片石墨,从而进一步提高涂层对镁合金的腐蚀防护性能.方法 利用化学氧化聚合法在鳞片石墨表面合成聚苯胺,通过X射线衍射仪、扫描电子显微镜、傅里叶变换红外光谱仪,对所得到的聚苯胺/鳞片石墨复合粉末进行表征.将合成的复合粉末均匀分散于环氧树脂中后,在AZ91D镁合金表面制备涂层,通过电化学阻抗测试对涂层在3.5％氯化钠溶液中的腐蚀防护性能进行研究.结果 聚苯胺可以在鳞片石墨的表面聚合,鳞片石墨的加入使聚苯胺环氧涂层的附着力略有降低,涂层硬度、柔韧性及耐冲击性能没有明显改变,但鳞片石墨的加入明显提高了聚苯胺环氧涂层的阻抗值.在浸泡前1488 h,苯胺与鳞片石墨的质量比为1:1时,涂层的阻抗值为1.3×108?·cm2,防护性能最好.但随着浸泡时间的延长,苯胺与鳞片石墨的质量比为4:1时,涂层的阻抗值逐渐高于其他涂层,当浸泡4008 h后,其阻抗值为1.6×108?·cm2,仍具有较优异的防护性能.结论 环氧涂层中添加聚苯胺/鳞片石墨复合粉末后,通过鳞片石墨前期的屏蔽与聚苯胺长期缓蚀的协同作用达到了对镁合金较好的防护效果,而涂层的这一防护效果和苯胺与鳞片石墨比例有关.     

不锈钢表面聚苯胺纳米纤维/改性氧化石墨烯/水性环氧复合涂层的制备与防护性能研究

在氧化石墨烯纳米片(GO)改性的基础上,于非盐酸介质中采用原位共聚法合成了聚苯胺纳米纤维/改性氧化石墨烯复合材料(PANI-F/CTGO),将其作为防腐增效组分引入到水性环氧聚合物乳液(WEP)中构建复合涂料。采用电化学方法和盐雾实验研究了涂料在加速腐蚀条件下对不锈钢的腐蚀防护作用,对腐蚀产物结构进行了分析。复合材料中PANI-F与CTGO的化学键接提高了PANI-F/CTGO在环氧乳液中的分散性和相容性。非盐酸介质条件下制备的PANI纳米纤维没有腐蚀介质盐酸的引入,在涂层中能发挥出更好的耐蚀性;PANI-F/CTGO/WEP涂层具有较高的开路电位(OCP)值和阻抗模,耐盐雾时间达到720 h,显示了优异的防腐性能,这主要是PANI-F/CTGO的主动钝化与物理阻隔协同作用的结果。     

不锈钢表面聚苯胺基复合涂层的制备与防腐蚀性能研究

目的 制备一种新型复合防腐涂层,增强316L不锈钢在中高温硫酸溶液中的耐蚀性.方法 首先使用化学氧化法在石墨(G)颗粒表面原位聚合聚苯胺(PANI),制得PANI/G复合材料,再使用环氧树脂(EP)作为粘结剂,制备PANI/G/EP复合涂层.对比了PANI/G/EP复合涂层与PANI/EP复合涂层及添加氧化石墨烯(GO...     

水性聚苯胺/海泡石/丙烯酸乳液复合防腐蚀涂层研究

目的研究水性聚苯胺/海泡石/丙烯酸乳液复合防腐涂层在NaCl溶液中对马口铁的防腐效果。方法采用原位化学氧化聚合方法,制备了聚苯胺/海泡石复合材料,并以丙烯酸乳液为成膜物质,制备了水性聚苯胺/海泡石/丙烯酸乳液复合防腐蚀涂层材料。通过扫描电镜和EDX对聚苯胺/海泡石复合材料的结构和形貌进行了表征。利用电化学交流阻抗谱、塔菲尔曲线和硫酸铜点滴试验,研究了海泡石/苯胺投料比、聚苯胺/海泡石复合材料用量、磷酸浓度等对复合涂层防腐性能的影响。结果扫描电镜观察显示,苯胺/海泡石复合材料具有纤维状结构。电化学测试及硫酸铜点滴试验表明,当海泡石/苯胺投料比为6:10、聚苯胺/海泡石复合材料用量为0.2%、磷酸浓度为0.1 mol/L时,其腐蚀电流密度为1.013X10~(-6)A/cm~2,腐蚀电位为-0.385V,极化电阻为14 350.8?,耐硫酸铜腐蚀时间为275 s,防腐效果最佳。结论当海泡石/苯胺投料比为6:10、聚苯胺/海泡石复合材料用量为0.2%、磷酸浓度为0.1 mol/L时,水性聚苯胺/海泡石/丙烯酸乳液复合防腐涂层对马口铁具有最佳的防腐效果。     

聚苯胺在防腐方面的研究及应用现状

聚苯胺(PANI)具有良好的热稳定性和环境稳定性,经掺杂后,具有导电性及电化学性,可作为填料应用于金属防腐领域。但其分子链骨架刚性强、分子间作用力大,不易加工成型,不溶于常规的有机溶剂,当其作为填料应用到防腐涂料中存在溶解性、分散性差且与金属基底附着力不强等缺点,如能对其进行合理有效的改性,则可解决上述问题。简要探讨了溶液聚合法、反相微乳液聚合法、模板聚合法以及电化学聚合法等PANI的制备方法,并针对PANI在防腐涂料应用中存在的问题,重点阐述了PANI的质子酸掺杂改性及复合改性等不同改性方法,通过掺杂不同的质子酸对PANI进行化学改性,可降低PANI分子链之间的相互作用,从而提高其溶解性、导电性和防腐性能。将不同性能的材料与PANI进行复合改性,改善分子间作用力,能提高其加工性,从而更好的应用于金属的腐蚀防护工作。最后介绍了PANI在腐蚀防护过程中的作用、在防腐蚀涂料中的应用及相关理论的研究现状,并指出PANI防腐涂层的研究重点和发展方向。     

纳米ZnS增强聚苯胺复合涂层的性能研究

采用水热法制备纳米Zn S,与化学氧化法制备的聚苯胺(PANI)按不同比例混合,制得纳米Zn S改性PANI复合物,将其涂覆于Q235碳钢表面制备复合涂层。采用SEM,AFM,XRD和FTIR表征纳米Zn S改性PANI复合涂层的表面形貌和结构,利用动电位极化和EIS研究复合涂层浸泡在3.5%(质量分数)Na Cl溶液中的腐蚀电化学行为。结果表明,纳米Zn S改性PANI复合涂层中Zn S和PANI二者均匀分散,显著提高其耐蚀性能。当Zn S和PANI的质量比为1∶1时,性能最优,在3.5%Na Cl溶液中浸泡7 d,复合涂层的保护效率高达99.9%;浸泡30 d后复合涂层的表面形貌发生变化,仍为致密的保护膜,对基底材料具有较好的保护作用,使其免受溶液离子的侵蚀。     

原位聚合聚苯胺改性NiFe-LDH复合涂层的防护性能研究

采用水热法结合原位化学氧化法在304不锈钢表面制备了不同种类NiFe-LDH (层状双氢氧化物)/聚苯胺(PANI)复合涂层。利用SEM、EDS能谱分析、XRD、FT-IR和XPS,对不同LDH的表面形貌和结构进行分析。采用极化曲线和电化学阻抗谱研究了涂层对基底的防蚀性能,并对其耐腐蚀机理进行探讨。结果表明,添加Fe(NO₃)₃得到层状结构的LDH,采用PANI改性可进一步优化LDH的表面结构。PANI和LDH之间存在化学键的结合,二者协同作用提升复合涂层的综合性能。在168 h浸泡期间,NiFe-LDH/PANI复合涂层在1 mol/L H2SO4溶液中具有良好的化学稳定性,为304不锈钢提供优良的物理屏蔽和阳极氧化保护作用。     

阴极气体O2对石墨烯/聚苯胺/不锈钢双极板耐蚀性的影响

目的 提高质子交换膜燃料电池(PEMFC)双极板的耐腐蚀性能。方法 采用循环伏安法(CV)在316L不锈钢(SS)基材上制备还原氧化石墨烯(rGO)/聚苯胺(PANI)层-层复合双极板。用透射电镜(TEM)和扫描电镜(SEM)进行形貌观察,用红外光谱(FTIR)和拉曼光谱(Raman)确定官能团结构,用紫外可见光谱(UV-vis)确定分子共轭状态,用X射线光电子能谱(XPS)确定化学成分和键合状态。在模拟PEMFC阴极工作环境下研究rGO/PANI/316L SS层-层复合双极板的耐腐蚀性能,向体系中通入氧气(O₂),测量开路电位(OCP)、电化学阻抗谱(EIS)和极化曲线评价双极板的抗腐蚀性能。结果 在离子液体1-乙基-3-甲基咪唑硫酸甲酯中,通过电聚合能够获得厚度为53μm的PANI膜层,在pH=4的0.03 mol/L K₂SO₄溶液中还原氧化石墨烯(GO),在PANI上获得厚度为10μm的rGO膜层。PANI呈中间氧化态,sp2杂化的r GO和PANI之间的相互作用使得共轭效应增强。连续致密的rGO覆盖在多孔的P...     

色氨酸功能化石墨烯改性水性环氧涂层的耐蚀行为研究

目的 提高石墨烯在有机涂层中的分散性,并赋予其一定的功能性,制备一种方法简单、环境友好、成本低廉的水性环氧复合涂层。方法 以氧化石墨烯为原料,以1-(3-二甲胺基丙基)-3-乙基碳二亚胺（EDC）为缩合剂,在常温下经酰胺化反应将天然缓蚀剂色氨酸接枝到氧化石墨烯表面。再利用水合肼将其部分还原,得到色氨酸功能化的石墨烯,并成功分散至水性环氧涂层中,制备出色氨酸功能化石墨烯/环氧复合涂层。选用红外光谱仪、拉曼光谱仪、扫描电镜及透射电镜对功能化石墨烯的片层结构和微观形貌进行分析;利用电化学工作站对复合涂层在3.5%NaCl溶液中的耐蚀行为进行评价。结果 色氨酸分子成功接枝在氧化石墨烯表面,且功能化的石墨烯在无水乙醇及水性树脂中表现出优异的分散性。在防护性能方面,较之于空白样及未改性石墨烯/环氧复合涂层,在浸泡40 d后,功能化石墨烯基复合涂层表现出最高的阻抗模值（107 Ω?cm2）及电荷转移电阻值。同时,在所有涂层中,经功能化石墨烯复合涂层覆盖后,金属基底表现出最为轻微的腐蚀。结论 功能性的石墨烯添加至水性环氧涂层中可以显著提高涂层的耐腐蚀性能。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.