碳纤维表面电镀铜

研究了碳纤维表面进行镀铜处理的镀液组分及工艺条件.电镀前先在马弗炉中600～800 ℃下对碳纤维进行氧化处理.镀液采用水浴加热,温度控制在35～40 ℃,电流密度为0.5～2.5 A·dm-2,最佳pH值为9.0±0.5.采用本实验工艺在碳纤维表面镀铜,效率高,镀层均匀,厚度为1.5～2.0 μm,基本上消除了"黑心"现象.     

影响碳纤维表面镀铜速率的因素

在碳纤维表面先化学镀铜再电镀铜可获得具有一定厚度且均匀的铜镀层.研究了甲醛、配位剂、稳定剂等用量、pH值、温度、电流密度、电解时间等对碳纤维增重率的影响,确定了镀铜的最佳配方,并用扫描电镜验证了镀铜效果.结果表明,最佳化学镀铜配方为16 g/L CuSO-4·5H-2O,25 g/L EDTA·2Na,15 g/L酒石酸钾钠,15 g/L NaOH, 5 mg/L 2,2′-联吡啶,15 mg/L K-4Fe(CN)-6,6 mL甲醛(分析纯).本法既较好地解决了碳纤维束的黑心问题,又可获得较厚的镀层,且镀层与碳纤维的结合更牢.     

添加剂在碳纤维镀铜中的应用

为了解决碳纤维因纤细疏水、表面惰性而镀铜困难及存在的"黑心"问题,以CuSO4为主盐,锌粉为还原剂,研究了4种不同类型添加剂:烷基苯磺酸盐、烷基磺酸盐、十二烷基脂肪酸盐和十二烷基脂肪酸盐 醋酸钠对碳纤维镀铜的影响.结果表明,十二烷基脂肪酸盐 醋酸添加剂最有利于碳纤维镀铜,能有效地解决碳纤维镀铜时经常发生的碳纤维束"黑心"问题;整束碳纤维被均匀、连续地镀上了铜;镀层和碳纤维结合牢固.     

碳纤维镀铜的研究

通过对碳纤维表面预处理,然后使用混合添加剂,以化学镀的方法在碳纤维表面镀铜,该方法有效地解决了对碳纤维镀铜时经常发生的碳纤维束"黑心"问题.在实验中观察到整束碳纤维被均匀连续地镀上了铜.通过扫描电镜观察镀铜碳纤维的断面,可以看到镀层和碳纤维结合得很紧密.     

铝及铝合金表面直接电镀铅工艺

铝及铝合金的电镀一般需要浸锌和预镀处理,工艺复杂,镀层质量不易控制.为此,将铝及铝合金经化学和电化学前处理后,直接置于加有细化剂、稳定剂和阻氢剂的电镀液中施镀,采用电流密度为0.5～2.0 A/dm2的直流电源进行电镀,所得镀层均匀、致密、表面光滑、无起泡、起壳现象,镀层与铝基底具有良好的结合力.本工艺比传统工艺程序简单、易操作,镀层质量高.     

玻璃纤维增强双马来酰亚胺树脂基复合材料表面金属化的研究

采用化学方法对玻璃纤维增强双马来酰亚胺树脂基复合材料的表面进行镀前处理,以提高金属化镀层的质量。金属化工艺过程包括：材料的镀前处理,化学沉积铜,电镀铜和电镀光亮镍。实验结果表明,复合材料表面的粗化工艺对于镀层的质量具有重要的作用,经过适当的化学处理,使材料表面具有均匀适当的粗糙度,同时改善表面的亲水性,提高表面对活性钯催化剂的均匀吸附能力,能够提高镀层与基体的结合力。     

碳纤维表面电镀镍研究

采用连续电镀法对碳纤维进行镀镍处理,利用扫描电子显微镜、能谱仪和热重分析等方法研究了镀镍碳纤维的物理化学结构及性能的变化.结果表明:镀层为纯净的镍,结合强度较好;镀层厚度的增加与电镀时间及电流密度分别呈线性正比关系.镀镍碳纤维的导电性和抗氧化性能得到了明显提高,电阻率可降低到0.74×10-6Ω·m,起始氧化温度提高了...     

化学镀铜前碳纤维预处理的研究

碳纤维具有疏水性和表面惰性,很难直接镀铜.为此,研究了碳纤维表面的预处理工艺、条件等技术参数.结果表明:高温灼烧除胶、过硫酸铵氧化、氯化银活化较好地改善了碳纤维的疏水性,大大提高了碳纤维表面的粗糙度,使碳纤维表面具有了催化活性.预处理后的碳纤维进行化学镀铜,其镀层光亮、均匀、致密,与基体的结合力较好.     

短碳纤维-铜复合材料的研制及导热性研究

研究了用粉末冶金法制造碳纤维-铜复合材料的王艺,对复合材料密度、硬度、导热性进行了测定。结果表明,在碳纤维电镀及制造工艺合适的条件下,采用粉末冶金法可以制得界面结合较好,碳纤维分布均匀的碳纤维-铜复合材料,且碳纤维含量对复合材料密度、硬度、热导率有十分明显的影响。     

镀锡层抗高温性能与工艺研究

针对铜基引线框架镀锡层高温易缩锡变色及常温不耐盐水腐蚀等问题，采用了不同电镀工艺，分析了镀层显微形貌、物相结构、抗电化学腐蚀性能与力学性能。结果表明：镀锡前，对铜表面进行充分去氧化及粗化，可极大提高镀锡层结合力，有效防止高温缩锡现象；镀锡后，镀层浸泡抗高温氧化剂，可有效防止高温发黄以及提高耐盐水腐蚀性能。     

碳纤维表面结构对复合材料吸湿性能的影响

通过改变阳极氧化处理程度得到了具有不同表面结构的碳纤维, 然后将其与环氧树脂加工成碳纤维/树脂基复合材料, 研究了碳纤维的化学结构与湿热环境下复合材料吸湿之间的关系。结果显示: 阳极氧化处理后碳纤维表面的活性显著提高, 碳纤维表面含氧官能团的含量大幅增加, 尤其是-OH由处理前18.62%提高到处理后的34.84%。随着湿热处理条件的改变, 复合材料的吸湿机理也有所差异, 且温度是影响复合材料吸湿的重要因素。碳纤维表面活性越高, 复合材料达到吸湿平衡时的平衡吸湿量越大, 而平衡吸湿量的增加又会导致复合材料层间剪切强度(ILSS)下降幅度增大。     

碳纳米管应用于聚合物抗静电纤维的研究

基于聚合物与抗静电载体混纺而形成的“海岛”型内部结构,通过极化放电而消除静电的抗静电原理,将碳纳米管应用于聚合物抗静电纤维。摩擦静电荷测试结果显示,碳纳米管由于具有优异的导电性,强化抗静电载体周围的电场,从而显著地提高了聚合物纤维的抗静电能力。经过改性处理的碳纳米管,如空气活化和酸处理等,抗静电效果更加显著,尤其是金属沉积处理的碳纳米管,抗静电效果最为显著。说明碳纳米管在抗静电聚合物纤维领域是很有应用前途。     

Preparation and Research of Electroless Copper on Carbon Fibers

In this paper, Cu coated carbon fibers were prepared using the electroless plating method. Effects of pretreatment, dispersing capability, formaldehyde, temperature, and pH on electroless plating process were studied. The connection between the Cu²⁺ concentration in the electroless plating solution and the plating time at different temperatures was studied. The process of the electroless Cu plating was analyzed and calculated, which derived the activation energy of the electroless copper plating on carbon fibers: Ea = 32.68 kJ/mol. The effect of the mass of carbon fibers and Cu coated carbon fibers which were dispersed in 80 mL distilled water on the conductivity of the solution was also studied. And as a result, the conductivity of the solution increased with the amount increasing. However, when the amount of the fibers was more than 0.08 g, the fibers would be incompletely dispersed. Thus, it could be concluded that the best accession amount of carbon fibers in 80 mL distilled water was 0.08 g. The corresponding conductivity values of carbon fibers and copper-coated fibers were 12.5 and 20.5 µs/cm, respectively.     

偶联剂处理镀镍碳纤维/环氧树脂界面特性

采用硅烷偶联剂KH560对镀镍碳纤维进行偶联处理。通过扫描电镜、 红外光谱、 接触角测量和单丝复合体系多次断裂法测试研究对比偶联处理前后碳纤维的表面形貌、 结构、 润湿性能以及纤维/树脂体系的界面状态和粘结性能。结果显示: 偶联处理后, 镍镀层表面平整, 羟基等表面极性基团增加, 表面涂覆的KH560膜层完整; 镀镍碳纤维/树脂界面的浸润性得到改善; 镀镍碳纤维/环氧树脂的界面处没有气泡产生, 断点两侧的脱粘现象减轻; 单丝饱和断点数由46增加到65; 镀镍碳纤维/环氧树脂的界面剪切强度由(34.87±2.23)MPa提高到(72.51±3.77)MPa。     

C/SiO2同轴复合纤维的制备及性能研究

以SiO₂溶胶为壳层,聚丙烯腈(PAN)溶液为芯层,采用同轴静电纺丝法制备了PAN/SiO₂同轴复合纤维. 经过预氧化,炭化处理,得到1μm的C/SiO₂同轴复合纤维. 采用傅立叶红外分析仪(FTIR)、X射线衍射分析仪(XRD)、扫描电镜(SEM)表征了同轴纤维结构和纤维截面形貌,表明利用同轴静电纺丝技术在碳纤维上制备了厚度约20nm的SiO₂涂层. 采用网络分析仪研究了同轴复合纤维的吸波性能,纤维质量分数为20％时,同轴复合纤维介电常数实部和虚部均比未涂层碳纤维低. 根据电磁参数采用RAMCAD软件计算了3mm厚材料反射率,在2～18GHz频率范围内,材料的最低反射率达到-17dB,对应的频率为12GHz,<-10dB的带宽为3.3GHz. 热重(DTA-TG)分析表明同轴复合纤维的抗氧化性能较未涂层碳纤维有所提高.     

Method for embedding optical fibers in an aluminum matrix by ultrasonic consolidation

The overall aim of the research, part of which is outlined in this paper, was to utilize the ultrasonic consolidation (UC) process for the fabrication of smart metal structures, capable of measuring an external stimulus and responding to this stimulus by adapting its structure accordingly through embedding both active and passive functional elements. This paper presents a fundamental study of embedding methods for the fabrication of optical fibers embedded within aluminum structures. The methods considered in this paper produced embedded optical fiber specimens in which large amounts of plastic flow were observed within the matrix. The matrix material deformed around the fibers, resulting in fully embedded optical fibers capable of transmitting a bright light source and without damaging the fibers. Based on light responses, a general process window was drawn to show the range at which optical fibers can be embedded within aluminum structures using the UC process. The outcomes lay down initial investigative principles for the further development of the technology for embedding or cladding of optical fiber sensors, such as fiber Bragg grating devices, within or on metal structures: for example, the cladding of large free-form metal structures or smart "skinned" metal foam or metal honeycomb structures.     

Laser direct writing polymeric single-mode waveguide devices with a rib structure

A focused argon-ion laser beam is used on a spin-coated polymeric thin-film deposited upon a SiO2/Si substrate to polymerize the core for fabrication of Gaussian profile optical channel waveguides. A rib structure that allows only the fundamental mode to propagate even with its higher dimension and high-index contrast between the core and the cladding was fabricated. When the thickness of the core-index region outside the rib section decreases, the waveguide produces higher-order modes at the output. The waveguide reported here has cross-sectional dimensions and numerical apertures that match the single-mode fibers for efficient coupling. I used a mixture of two intermiscible acrylate monomers for the cladding and the core of the waveguides. The polymerization process and its dependent dwell time or scan speed and the laser power intensity are shown. I present the operational characteristics of directional couplers using a rib waveguide structure with a core-cladding index difference.     

热轧锭杆“黑心”问题的探讨

锭杆是纺机中一种数量大、转速高、尖端要求耐磨的杆状零件。用热轧方法生产的锭杆毛坯,在其纵、横截面上经酸蚀后出现了“黑心”问题。本文通过一系列试验和观察证实“黑心”并非疏松,“黑心”的存在也不影响耐磨性。从而否定了由于“黑心”是疏松而需将现行热轧方法改用车削方法生产锭杆毛坯的论点。本章对“黑心”形成的原因作了分析和探讨,认为“黑心”是由于斜轧时各部分变形不均匀,而使不同区域里纤维状组织的纤维变形形式不同所致。     

化学镀镍碳纤维/环氧树脂复合材料电磁屏蔽性能

采用化学镀方法对碳纤维进行表面镀镍, 采用SEM、 EDX、 XRD分析了镀镍碳纤维的微观形貌、 镀层成分和镀层结构, 通过电阻测试研究了镀镍碳纤维的导电性。将体积分数为2.5%、 5%、 7.5%、 10%的镀镍碳纤维作为导电填料制备镀镍碳纤维/环氧树脂复合材料, 并用屏蔽室法测试了不同频段复合材料的屏蔽效能。结果表明: 碳纤维化学镀镍后, 表面形成了一层均匀的复合镀层, 镀层中镍的质量分数高达94%, 镀镍碳纤维的电阻值仅为碳纤维原丝的1/54。镀镍碳纤维/环氧树脂复合材料的电磁屏蔽能力较碳纤维原丝有所提高。复合材料的屏蔽效能随镀镍碳纤维添加量的增加而升高。在低频频段(kHz频段), 复合材料的屏蔽能力主要决定于材料的本征参数, 不同镀镍碳纤维含量的镀镍碳纤维/环氧树脂复合材料的屏蔽能力相差不大; 在中高频频段(MHz、 GHz频段), 镀镍碳纤维/环氧树脂复合材料屏蔽效能主要决定于材料的电阻率。     

Electrolytic Metallic Coatings for Carbon Fibers

This paper concerns electrolytic metallic coatings for carbon fibers and the related processes. Plating bath design, electrolyte selection and other aspects were investigated. Experimental results especially in copper electroplating show that the uniformity of metallic coatings on carbon fibers can be improved by the modification of plating bath and the selection of electrolytes. Thus continuous and uniform metallic coatings can be obtained on carbon fibers, even if the cross section of carbon fibers has irregular shape. Polarization tests on different copper baths was performed. Electrodeposition of other metallic layers such as nickel, cobalt, and copper/tin duplex layer was also introduced. A process of two or more than two plating steps in which different electrolytes may be used for same metal deposition was proposed to expedite the coating procedure