等离子喷涂铝电解可湿润TiB2阴极涂层研究进展

铝电解工业越来越多的采用石墨阴极,石墨阴极具有良好的导电性能,但石墨不被铝液湿润且和铝液形成Al4 C3,导致铝电解槽运行寿命短.可湿润TiB2涂层阴极因节能和延长槽寿命能够给铝电解工业带来显著效益.等离子喷涂是一种高效、灵活的沉积涂层的方法 ,能够在形状复杂或大表面积的基体上沉积金属间化合物、陶瓷或复合材料,涂层厚度可从数微米到数毫米.等离子喷涂制备可湿润性TiB2涂层阴极是可行有效的方法 ,本文评述了等离子喷涂制备可湿润TiB2阴极涂层的研究进展,简述了等离子喷涂工艺受到的影响因素(包括粉末性质、基体表面形貌和焰流性质)和涂层与基体材料结合的机制(包括机械结合、冶金结合和物理结合),分析和讨论了TiB2粉末制备、基体预处理、等离子喷涂工艺参数、涂层显微结构和性能等.最后,指出了等离子喷涂制备可湿润性TiB2涂层阴极工艺将来研究需要解决的几个关键问题.     

熔盐体系中电沉积制备TiB2镀层的研究现状

介绍了熔盐体系中电沉积制备TiB2镀层技术中熔盐的选择、电镀工艺和参数的选择，概述了不同熔盐体系中B离子、Ti离子在阴极沉积的电化学机珲以及TiB2的合成机理，论述了TiB2惰性阴极在铝电解工业中的研究现状，最后分析了熔盐体系中石墨电极上制备TiB2镀层的可行性。     

钛金属表面熔盐电解法制备TiB2/TiB表面层

运用渗硼技术改进金属钛及其合金的表面特性。以无水硼砂为主渗硼剂,无水碳酸钠为助熔剂和高温络合剂的渗剂体系,在电流密度为7.3 A/dm2,保温温度为900℃,通电时间为30 min的电解渗硼工艺下制备出复合硼化物表面层。通过热重与差热图谱确定几种硼砂-碳酸钠配比体系的初晶温度。对4种不同配比的渗硼剂试验得到的样品做XRD测试,分析了相结构。并对硼化物生长机理与结构进行了研究与分析。结果显示:质量比为8∶2的渗硼剂组成最优。纯硼砂电解的样品表面物相组成与二渗硼钛标准粉末的XRD完全吻合。钛金属表面主要生成TiB2与TiB;扫描电镜图像可知渗硼表面致密,TiB2与TiB分层较为明显;TiB厚度可达35μm,TiB2厚度为43μm。     

改进的二硼化钛基惰性阴极耐蚀性的研究

用冷压烧结法制造了TiB2-MoSi2惰性阴极,得到致密的二硼化钛基惰性阴极试样。在电解实验后,通过对二硼化钛阴极的表面和剖面的电子显微分析,发现铝液对此种惰性阴极的湿润性好于电解质对惰性阴极的湿润性,避免了电解质与阴极表面的接触,发现惰性阴极的腐蚀为电解南对阴极晶界的腐蚀,测得腐蚀速度为2．22mm/a,证明其耐蚀性能良好。     

Electrolytic properties and element migration in Ni-TiB_2/Al_2O_3composite cathode

With alumina sol as binder and Ni metal as sintering aids,the Ni-TiB_2/Al_2 O_3 composite cathode material for aluminum electrolysis was prepared by coldpressed sintering.The mechanical properties of the composite cathode material were measured.Its electrolytic properties were identified by a 20-A electrolysis test.Cathode samples before and after electrolysis test were measured by energy-dispersive spectroscopy(EDS).The migration behavior of various elements in the electrolysis process was studied by phase analysis.The result shows that Ni metal can effectively fill the gap between the aggregate during the sintering process,which can improve the sintering density of the composite cathode material significantly.The voltage of the 20-A electrolysis test is stable.The impurity of aluminum liquid is 0.42%.The aluminum liquid can wet the cathode surface effectively,and the Ni-TiB_2/Al_2 O_3 composite is an ideal wettable cathode material.In the process of electrolysis,the alkali elements in the electrolyte penetrate the electrode,where K goes deeper than Na.Al generated on the cathode surface will also penetrate the cathode through the gap of the composite material,while Ni in the electrode will spread into the aluminum liquid layer.     

含环氧树脂微胶囊自修复涂层的制备及其性能

目的制备含环氧树脂微胶囊的二元自修复涂层,并对其力学性能和自修复性能进行研究。方法将自制环氧树脂E-51/三聚氰胺-脲醛树脂微胶囊和潜伏型固化剂(2-甲基咪唑)按一定比例添加到环氧树脂基体中,制备二元自修复环氧树脂涂层。利用漆膜弹性试验机、漆膜冲击试验机和万能拉伸试验机对涂层的弯曲性能、耐冲击性能和拉伸性能进行测试。利用扫描电子显微镜(SEM)、光学显微镜(OM)对涂层的自修复性能进行考察。采用EIS对涂层的电化学性能进行测试。结果成功制备了含环氧树脂微胶囊二元自修复涂层,当涂层中微胶囊的质量分数为3%时,涂层的冲击强度和拉伸强度分别提高了10.6%和14.6%。当涂层中2-甲基咪唑和微胶囊质量分数分别为6%和5%时,涂层的自修复性能较佳。当微胶囊质量分数为9%时,涂层的电化学阻抗值可达1.2×105?。结论微胶囊的加入可有效提高涂层的冲击强度和拉伸强度。随着涂层中潜伏型固化剂含量的增大,涂层的自修复性能增强。当潜伏型固化剂含量达到一定值时,涂层的自修复性能随着微胶囊含量的增大而增强。随着微胶囊含量的增加,涂层的电化学阻抗值增大。     

不同粘结剂基TiB_2-C复合阴极中碱金属的渗透迁移行为(英文)

在含K低温电解质熔体中,采用EDS及改进型电解膨胀率测试仪,分别研究电解过程中沥青、呋喃、酚醛、环氧基TiB2-C复合阴极中碱金属(K和Na)的渗透迁移路径。同时,计算并讨论相应的电解膨胀率、碱金属的扩散系数以及复合阴极的腐蚀率。结果表明:无论使用何种粘结剂,电解过程中,碱金属在阴极中表现出相似的渗透迁移路径:碱金属首先渗透进入阴极的孔隙当中,随后渗透进入粘结剂相中,随着电解的不断进行,最后渗透进入复合阴极的骨料相当中。渗透进入粘结剂相和炭质骨料相当中的K和Na均会引起复合阴极的电解膨胀,同时,K比Na有着更强的渗透力。树脂基复合阴极的电解膨胀率、碱金属在其中的扩散系数以及腐蚀率均小于沥青基复合阴极,即,树脂基复合阴极的抗碱金属渗透力强于沥青基复合阴极。而就树脂基TiB2-C复合阴极而言,酚醛基TiB2-C复合阴极的抗渗透力最强,碱金属在其中的渗透速率、扩散系数和相应的腐蚀率分别为4.72mm/h,2.24×10-5 cm2/s和2.31 mm/a.     

Tribological Performance of TiB2-Ni Composite Coating Deposited by APS

TiB2-Ni composite powders were prepared by pressurized hydrogen reduction cladding with different proportion of TiB2.The coatings were then prepared by APS.The microstructures and the phase composition of the powders as well as the deposited coatings were analyzed by scanning electron microscopy(SEM)and X-ray diffraction(XRD).The coatings were tested using a ring-on-disc tribometer from ambient temperature to 300°C.A sprayed Cr3C2-NiCr coating was tested as a reference.The morphologies of the worn surface of the coatings were observed and analyzed.It is found that the TiB2-Ni composite coatings present higher friction coefficient than that of the Cr3C2-NiCr coating at room temperature due to the adhesive wear mechanism,whereas the main wear mechanism of Cr3C2-NiCr coating is rupture and exfoliation.However,at high temperature,the friction coefficient of the TiB2-Ni composite coating decreases as a result of B2O3 solid lubricant,which alleviates the adhesive wear on coatings.Furthermore,the TiB2-Ni composite coating greatly reduces the mass loss of the boron cast iron.     

氟硅树脂改性紫外光固化易清洁涂层的制备及性能研究

目的 以聚氨酯丙烯酸酯为基体树脂、氟硅树脂为添加剂,制备一种具有疏水、防涂鸦和耐磨性能的紫外光固化易清洁光滑涂层。方法 首先采用氨基甲酸酯化反应合成一种含硅氧烷结构的三官能度丙烯酸酯单体（TATES）。然后以1H,1H,2H,2H-全氟辛基三甲氧基硅烷（POTS）、丙基三甲氧基硅烷（MPMS）、TATES为原料,通过水解-缩聚法制备了一系列氟硅树脂（AFSR）。最后将AFSR添加到聚氨酯丙烯酸酯树脂中,经紫外光固化得到氟硅树脂改性的聚氨酯易清洁涂层。系统地研究了AFSR添加量对涂层润湿性、自清洁、防涂鸦及耐磨性的影响。结果 氟含量为92.6%（物质的量分数）的AFSR在PUA中的添加量为2.5%时,涂层表面的水和十六烷的接触角分别为112.6°和66.3°,且拥有很低的水和十六烷滑动角。随着涂层中AFSR添加量从0.5%增加到2.5%,防污性能逐渐提高,具有明显的油性记号笔收缩和自清洁效果,并且易清洁涂层经过3 000次的摩擦循环后,仍具有良好的收缩效果和持久的防污性能,表明涂层具有优异的耐磨性能。结论 随着AFSR添加量的增加,涂层中氟硅含量增加,表面能降低,使得涂层拥有高的接触角与...     

铝电解质对TiB2镀层的渗透

采用熔盐体系在石墨基体上电沉积制备了TiB2镀层．将TiB2镀层和铝电解阴极碳块和石墨分别作为阴极，考察了Na和电解质对其渗透腐蚀．电解4h后，由酚酞试剂检测表明，Na对TiB2镀层的渗透深度为零，对阴极炭块的渗透深度为16mm，对石墨的渗透深度为4mm．电子探针的分析结果指出，Na和F元素渗透到石墨基体的量很少，元素Al相对较多，TiB2镀层阻碍了Na的产生并减缓了Na的渗透，但没有改变Na的渗透机理．同时。镀层与基体的结合力良好，Al对TiB2镀层的湿润性良好．     

潜伏性环氧固化剂的制备及其水性环氧涂料的性能研究

以双酚A、甲醛、双氰胺等为原料,合成了环氧树脂潜伏性固化剂,采用差热分析(DTA)研究了潜伏性固化剂/环氧树脂E-51体系的固化行为,并研究了所配制水性环氧涂料乳液的稳定性和漆膜性能。研究结果表明:该潜伏性固化剂固化E-51环氧树脂的最佳用量为45%,固化温度为150℃;乳液稳定性好,以3 000r/min离心30min不分层,乳液粒径为0.38μm,室温下可储存6个月以上,而且该水性涂料漆膜表面光滑平整,性能优良。     

船用低温固化丙烯酸聚氨酯防腐蚀涂料

目的研制具有低温固化性能的长效耐候船用丙烯酸聚氨酯面漆。方法采用聚天门冬氨酸树脂对羟基丙烯酸树脂进行改性,配合使用受阻胺光稳定剂与紫外光吸收剂作为体系光稳定剂,选用改性高分子不饱和羧酸盐类分散剂、氟改性聚丙烯酸酯类流平剂、聚酰胺蜡类触变防沉剂,配合使用湿法绢云母、钛白粉、重晶石粉作为体系颜填料。结果通过控制天门冬氨酸树脂NH1420的不同添加量与优化助剂体系、颜填料体系,涂料体系在-5℃环境下表干55 min,实干时间14 h,24 h可复涂,放置10 d后,漆膜硬度可达2H,涂层具有良好的长效耐候性能。结论聚天门冬氨酸树脂有效改善了丙烯酸聚氨酯面漆的低温固化性能,配合使用受阻胺光稳定剂与紫外光吸收剂,提高了涂层的耐候性。研制的船用低温固化丙烯酸聚氨酯防腐蚀涂料具有良好的低温固化性能、机械性能、耐腐蚀性能与耐候性。     

高固体分环氧海洋防腐蚀涂料的研究进展

海洋环境中,钢结构的腐蚀不可避免,有机涂层是一种延缓金属腐蚀的最有效、最经济的材料之一。其中高固体分环氧涂料由于绿色环保、涂层致密性好、可厚涂等特点在海洋重防腐中得到广泛的应用。对目前高固体分环氧厚膜、超厚膜涂料的研究进展,存在的问题及解决方法进行了详细的介绍。其中,环氧树脂、胺类固化剂作为环氧涂料中的主要的成膜物质,对涂层的性能起着关键的作用。总结了几种在高固体分环氧涂料中切实可行的环氧树脂增韧改性方法,同时指出开发耐冲击性能优异,耐高温,低温固化、水下固化的环氧固化剂也是环氧固化剂的发展趋势。通过曼尼希碱改性合成的环氧固化剂,恰好能满足各种性能的要求,阐述了该类环氧固化剂的合成研究进展状况。     

Colloidal Alumina-bonded TiB_2 Coating on Cathode Carbon Blocks in Aluminum Cells

In order to solve the serious pollution of industrial altunintim electfolysis cell, the researchand development of the usage of inert anode andcathode has an importal significance. However, the lltilization of inert anode is not successful yet, the using of titanium diboride as a mixtUre of carbon for use as the ineft cathode prepared by coating TiB,-C mixtllfe for the electfolysis of altunina in Hall-Heroult cell is wellknownll--6]. With such a cathode, a large savingin the production cost …     

静电喷涂高附着力疏水涂层及其性能

目的提高静电喷涂疏水涂层的附着力。方法采用硅烷偶联剂和聚二甲基硅氧烷制备了表面改性疏水二氧化硅粉末。将一定比例的聚偏氟乙烯粉末、超高分子量聚乙烯粉末与疏水二氧化硅粉末混合,制备了复合型疏水粉末。使用环氧树脂、固化剂、活性剂等配制了导电环氧树脂。通过静电喷涂工艺将复合疏水粉末喷涂到已用导电环氧树脂覆盖的铝基板表面,经过中温固化,制得了铝合金疏水复合涂层。采用扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FTIR)、接触角测量仪(CA)、百格刀附着力测试仪等,对疏水复合涂层进行测试表征。结果 SEM结果表明涂层表面构建了微米-纳米的阶层粗糙结构,经CA测试,该表面具有较好的疏水性。当混合粉末中聚二甲基硅氧烷改性二氧化硅的比例占到20%时,环氧基疏水涂层的接触角最高可达到140°,滚动角最低可达5°,附着力的等级为0级,同时疏水涂层的耐磨性和耐腐蚀性良好。结论采用简单、易于工业化的静电喷涂工艺制备了高附着力的疏水涂层,具有广泛的应用前景。     

超音速大气等离子喷涂TiB2−SiC涂层的制备与性能

将喷雾造粒制备的TiB2?SiC粉末进行真空煅烧,采用超音速大气等离子喷涂制备TiB2?SiC涂层,研究喷涂功率和喷涂距离对TiB2?SiC涂层性能的影响,并对超音速等离子喷涂制备TiB2?SiC涂层的工艺进行优化.结果表明:煅烧后的喷涂粉末粒径分布均匀,球形度良好,流动性增强.煅烧粉末制备的涂层结构致密、沉积效率高....     

Electrolytic preparation of Al-Ca master alloy on liquid Al cathode

1　ＩＮＴＲＯＤＵＣＴＩＯＮＡｓａｎｅｗｌｙｄｅｖｅｌｏｐｉｎｇｓｕｐｅｒ ｐｌａｓｔｉｃａｌｕｍｉｎｕｍａｌｌｏｙ ,Ａｌ Ｃａａｌｌｏｙｈａｓｎｏｔｏｎｌｙｇｏｏｄｐｌａｓｔｉｃｉｔｙ ,ｂｕｔａｌ ｓｏｇｏｏｄｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｙ ,ｇｏｏｄｗｅｌｄｉｎｇｐｒｏｐｅｒｔｙａｎｄｓｔｒｏｎｇｒｅｓｉｓｔａｎｃｅｏｆｃｏｒｒｏｓｉｏｎａｆｔｅｒｂｅｉｎｇｆｏｒｍｅｄ .Ｔｈｅｒｅｆｏｒｅ ,ａｌｏｔｏｆｍｅｔａｌｌｕｒｇｉｃａｌｓｃｉｅｎｔｉｓｔｓｈａｖｅｄｅｖｏｔ ｅｄｔｏｔｈｅｒｅｓｅａ…     

压载水舱高固体份环氧涂料的研究

目的提高压载水舱环氧涂料的耐阴极剥离性能。方法以双酚A型环氧树脂、酚醛环氧树脂、C9石油树脂和双酚F型环氧树脂为涂料的主要成膜树脂,采用四因素四水平的正交试验,对四种树脂的用量进行优化。固化剂采用聚酰胺固化剂和改性酚醛胺固化剂进行混合,以获得良好的物理化学性能。对涂料的颜基比及助剂进行了分析研究,以确定涂料各组分的用量。结果通过四因素四水平的正交试验,确定了涂料四种树脂的用量。当聚酰胺固化剂和改性酚醛胺固化剂的混合比例为2:1时,涂料具有较佳的抗阴极剥离性能。通过对颜填料不同颜基比(0.75:1~1.5:1)的研究,当涂料的颜基比为1:1时,涂料的耐阴极剥离性能最好。结论通过对涂料的成膜树脂、固化剂及颜基比的研究,制备的压载水舱环氧涂料具有优异的耐阴极剥离性能及良好的耐海水性、耐盐雾性及抗腐蚀蔓延性等性能,能够满足船舶压载舱的防腐需求。     

Research progress in TiB<Subscript>2</Subscript> wettable cathode for aluminum reduction

Titanium diboride wettable cathodes are regarded as ideal for aluminum reduction because of their excellent wettability with molten aluminum. The TiB₂ inert wettable cathode materials for aluminum reduction may be divided into three groups: pure TiB₂ ceramic cathode, TiB₂ composite cathode, and TiB₂ coating. This paper briefly describes international research progress on TiB₂ inert wettable cathodes as well as problems faced, and concentrates on the activities of Central South University, Changsha, China, in researching the ambient-temperature solidified TiB₂ cathode coating. At the same time, the results of the coating applied in many aluminum smelters in China are presented, and the pattern of cathode surface of 160 kA cells coated with the ambient-temperature-solidified TiB₂ cathode coating after one year operation is discussed in comparison with the normal cells.     

Research on Properties of Carbon Fiber/Epoxy Resin Composite Material by Microwave Curing

Microwave irradiation was used to reduce the curing time of carbon fiber/epoxy resin composite material.The properties of carbon fiber/epoxy resin composite material under microwave curing were investigated by thermogravimetry(TG),dynamic mechanical analysis(DMA),impact strength test and scanning electron microscope(SEM).The results show that composite materials patch have high thermal stability after microwave curing.The initial degradation temperature is 330.9℃,the maximum thermal decomposition rate is at 368.1℃.When the layer of composite materials patchis 4 layers,the dynamic mechanical properties are the best after microwave curing.The initial storage modulus is 43.2 GPa,increased 28.3 GPa and 27.1 GPa than 3 layers and 5 layers,the glass transition temperature(Tg)is 67.48℃,increased about 12 ℃than 3 layers and 5 layers.Microwave curing can significantly improve the infiltration capacity of epoxy resin,enhance interfacial bonding,and increase the impact strength of composite patch.Under microwave curing,the impact strength of 3,4,5-layers composite material patches increases 35.9%,6.4% and 15.1%,respectively than heating curing.The SEM analysis of impact fracture surface shows that microwave curing can improve the interface of carbon fiber and epoxy resin.