三种导电防腐涂层的耐蚀性能研究

分别制备聚苯胺改性石墨烯、纳米粒子改性石墨烯和石墨/炭黑复合物三种导电防腐涂料,并将其分别涂覆在Q235钢表面制备导电防腐涂层接地材料。采用接触角仪、电化学阻抗谱、Tafel极化曲线和光学显微镜,研究了该上述涂层在酸性土壤模拟液中的腐蚀性能。结果表明:三种导电防腐涂层均具有优良的防腐性能和较大的接触角。纳米粒子改性石墨烯涂层和聚苯胺改性石墨烯涂层防腐效果大于石墨/炭黑复合导电涂层。纳米粒子改性石墨烯涂层和聚苯胺改性石墨烯涂层的保护效率分别高达92.09%和91.44%。     

高导电特种粉体材料及导电涂料研究

采用快速凝固雾化技术制备Cu-Ag(质量分数为10%～30%)系列超细铜银合金粉末,再结合化学镀的方法制备了Ag/Cu-Ag包覆粉末.通过扫描电子显微镜(SEM)、X射线衍射(XRD)以及电阻测量等方法对粉末及涂料性能进行表征,检测了涂料的表面电阻、电阻率等.结果表明:银包覆超细铜银合金粉末为球形和近球形、表面致密、镀银层均匀,制作的导电涂料表现出优异的导电性能;并且随着银质量分数的增加,涂料的表面电阻和电阻率减小,趋近于纯银涂料.银包覆超细铜银合金粉末既克服了铜粉易氧化的缺陷,又解决了银粉价格高等问题.还对导电涂料的导电机理、影响因素及应用领域进行了分析和说明.     

聚苯胺/石墨烯原位复合水性防腐涂料耐蚀性能的研究

目的研究聚苯胺/石墨烯水性防腐涂料的耐蚀性能。方法采用盐酸为掺杂酸,以聚乙烯基呲咯烷酮(PVP-K30)为空间稳定剂,利用原位聚合法,以苯胺和石墨烯为原料,过硫酸铵为氧化剂,制备聚苯胺/石墨烯复合材料。将聚苯胺/石墨烯、纯聚苯胺、石墨烯分别添加到HG-54C乳液中制备水性防腐涂料,利用动电位极化曲线和盐雾试验对比分析聚苯胺/石墨烯、纯聚苯胺、石墨烯水性涂层的防腐性能,再通过傅里叶红外光谱(FTIR)、扫描电镜(SEM)对比分析其结构和微观形貌。结果聚苯胺均匀地覆盖在石墨烯的片层结构上形成氧化插层结构。当复合材料浸泡在3.5%Na Cl溶液中,腐蚀电流密度为2.3955×10-7A/cm2。盐雾试验表明,聚苯胺/石墨烯的防腐性能优于添加纯聚苯胺和石墨烯的性能。结论聚苯胺/石墨烯涂层具有良好的耐蚀性能,其耐蚀性能优于纯聚苯胺涂层和石墨烯涂层。     

SSA 掺杂的苯胺 / 吡咯导电共聚物的制备及结构表征和防腐蚀性能

在磺基水杨酸(SSA)的酸体系中,以过硫酸铵为氧化剂,采用化学氧化聚合法,调整聚合单体配比,制备了SSA掺杂的苯胺/吡咯导电共聚物(PANI/PY-SSA),通过FT-IR,SEM和XRD等测试手段对其分子结构、微观结构和有序化程度进行了表征。同时,将该导电共聚物加入到环氧树脂涂料中,通过Tafel极化曲线和EIS阻抗谱研究了PANI/PY-SSA对低碳钢材料的防腐蚀性能。结果表明,PY共聚改性明显提高了聚苯胺对金属的保护能力,且当聚合单体配比n(AN)∶n(PY)=3∶7时,制备的PANI/PY-SSA防腐蚀性能最好,涂层的Ecorr为-0.335 V,Jcorr为7.972×10-8 A/cm,RC为2.103×105Ω·cm2,CC为1.646×10-8 F/cm2。     

高氯酸掺杂聚苯胺复合阴极的制备及性能研究

目的 为提高聚苯胺海水电池正极的导电性和放电性能,研究各种制备工艺条件对电极性能的影响。方法 采用电化学的方法,以石墨纸为载体,在高氯酸体系中制备聚苯胺（PANI）/二氧化锰（MnO₂）/氧化石墨烯（GO）复合电极,研究复合电极制备的最优条件。采用X射线衍射仪、红外光谱仪和扫描电镜表征复合电极,采用交流阻抗法、循环伏安法和极化曲线研究电极的电化学性能。结果 石墨纸在室温下经30 mA/cm²的电流密度氧化60min后,在磺基水杨酸（SSA）质量浓度为15g/L,硫酸锰浓度为0.2mol/L的苯胺-高氯酸溶液里以电流密度18mA/cm²聚合20min,可制备出较优的PMGO复合电极,它与镁合金组成海水电池,以200 mA/g恒流放电至1 V,其比能量可达600 W·h/kg。PMGO复合电极的表面微观形貌是由纳米线组成的三维立体网状结构,聚苯胺与二氧化锰成功复合到氧化石墨烯表面。结论 高氯酸体系掺杂的聚苯胺导电性增强,氧化使石墨纸表面形成大量的氧化石墨烯,为苯胺聚合、复合提供大量活性点,复合后电极比表面积增大,与电解液充分...     

表面接枝含氟树脂改性HGB的制备及性能研究

目的对中空玻璃微珠(HGB)进行表面接枝含氟树脂改性,以其为填料制备含氟树脂涂料,并进行性能研究。方法将中空玻璃微珠分别经NaOH溶液、硅烷偶联剂KH550、HDI三聚体、含氟树脂处理,并通过FTIR、SEM、EDS等表征手段对接枝情况进行验证。以制备的表面接枝含氟树脂HGB(F-HGB)为填料,制备了含氟树脂隔热涂料,研究了HGB改性温度、时间对F-HGB接触角的影响,以及HGB粒径、添加量、改性、涂层厚度对涂料的疏水性能、隔热性能、拉伸强度的影响。结果成功制备出F-HGB,50℃下接枝含氟树脂反应8h,F-HGB与纯水的静态接触角为149.21°。与HGB/含氟树脂涂料相比,F-HGB/含氟树脂涂料的疏水性能、隔热性能、拉伸强度均有较大幅度的提高和改善。当F-IM16K添加量为20 phr时,F-HGB/含氟树脂涂层与水的接触角为100°,模拟曝晒实验涂层试板温差为7.4℃,拉伸强度为10.39 MPa。当F-K1添加量为20 phr时,F-HGB/含氟树脂涂层的导热系数为0.0701 W/(m·K),同时涂层隔热性能随HGB粒径、添加量的增大而增强,拉伸强度随之降低,但表面改性能有效减小涂料拉伸强度的降低幅度。结论 F-HGB具有疏水、隔热、与含氟树脂相容性好的特点,可作为功能填料制备疏水、隔热、力学性能优良的多功能涂料。     

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。     

电聚合表面改性对电容器用高纯铝箔侵蚀行为的影响

在铝箔表面电聚合制备导电聚合物薄膜,进行表面改性,并在硫酸-盐酸-硝酸钠电解质体系中采用直流方式进行电蚀,研究电聚合表面改性对铝箔电蚀的行为的缓蚀效果及缓蚀机制。研究结果表明:聚合物薄膜通过傅里叶红外检测为酸掺杂态。导电聚合物薄膜覆盖在铝箔表面使其维持高电位,腐蚀介质透过聚合物膜层,使铝发生溶解,在膜层处生成气相,导电聚合物膜层起到阴极作用,促进了铝箔腐蚀形成孔径大小相似的隧道孔,提高了发孔密度和隧道孔长度,气相破坏膜层且阴极薄膜发生氧化还原反应,对铝箔表面过蚀行为起到缓蚀作用。对比聚苯胺薄膜和聚吡咯薄膜对铝箔直流电蚀行为影响,通过扫面电镜图(SEM)和金相断面(OM)分析,表明聚苯胺薄膜的缓蚀效果更为明显,有效提高了表面发孔密度,改善了铝箔表面的过蚀现象,改善了隧道的孔形貌。     

纳米SnO_2/聚苯胺/环氧复合涂层的防腐蚀性能

采用原位氧化聚合法合成了不同质量比的纳米SnO2/聚苯胺复合材料,运用扫描电镜(SEM)、原子力显微镜(AFM)和X射线衍射(XRD)对材料进行表征,并在304不锈钢表面制备了纳米SnO2/聚苯胺的环氧涂层,利用电化学工作站和浸泡增重试验研究其耐蚀性能。结果表明,纳米SnO2/聚苯胺复合材料的防腐蚀效果优于聚苯胺,且当SnO2在复合材料中的质量分数为4%时,防腐蚀性能最佳。依据不锈钢表面复合涂层的结构,建立合理的等效电路,结合电化学阻抗谱数据,研究了纳米SnO2/聚苯胺/环氧复合涂层耐蚀性增强的机制。     

耐高温导电导热防腐蚀涂料的研制和机理分析

采用聚全氟乙丙烯和聚苯硫醚树脂共混改性,用炭系混合物为导电填料研制耐热、耐腐蚀和导电(导热)涂料.通过研宄导电填料种类、添加量和混合填料的比例对涂层导电性能的影响,确定了涂料的配方:PPS70%;FEP5%;填料25%(石墨:炭黑=3:1)所得涂层的具体技术指标为:导电性能:0.36Ω·m;耐腐蚀性能:能在200℃下耐强酸、强碱和有机溶剂的侵蚀(氧化性酸除外).在相同填料含量下,混合填料的涂层比单一填料涂层导电性能好,其原因是不同空间构型的导电粒子之间配合更有利于在涂层中形成三维导电网络.     

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.