玻璃纤维表面化学镀钴–铁–磷合金

对玻璃纤维进行丙酮除胶、乙醇除油、NH4F粗化、胶体钯活化、盐酸解胶、次磷酸钠还原等前处理后,以碱性化学镀工艺在其表面镀覆了Co–Fe–P合金。采用扫描电子显微镜观察镀层微观形貌,利用能谱仪分析其化学成分,通过热震试验测试镀层与玻璃纤维的结合力。结果表明,玻璃纤维表面镀层覆盖均匀、完整,结合力良好,镀层中Co、Fe、P的质量分数分别约为90%、4.1%和4.5%。经化学镀Co–Fe–P合金处理后,玻璃纤维在8.2～12.4GHz波段内的微波吸收性能明显改善。     

预处理工艺对钛合金电镀镍-磷合金的影响

采用不同工艺预处理(包括活化、活化+化学预镀镍和阳极氧化)TC4钛合金后再电镀Ni–P合金,对比了所得Ni–P合金镀层的表面粗糙度、显微硬度、微观形貌和结合力。"活化+预镀镍"预处理工艺(即砂纸打磨→除油→粗化→酸洗→活化→蒸馏水洗涤→化学预镀镍→蒸馏水洗涤)效果最好,所得Ni–P合金镀层平整、致密,厚度分布均匀,结合力好,显微硬度为625 HV,表面粗糙度为0.626μm。     

液压活塞杆上电镀铁镍钨和镍钨磷合金的耐磨和耐蚀性能比较

在45钢表面电镀了Fe–Ni–W和Ni–W–P合金。对比了两种钨合金镀层热处理后的显微硬度、元素组成和结晶情况,通过磨擦磨损试验、中性盐雾试验和浸泡腐蚀试验比较了它们的耐磨和耐蚀性能。Fe–Ni–W和Ni–W–P合金镀层均光亮、平滑,晶粒尺寸均在10~40 nm范围内,摩擦因数分别为0.086 1和0.094 4。Ni–W–P合金镀层的耐蚀性优于Fe–Ni–W合金镀层,经中性盐雾试验、5%盐酸浸泡和5% NaOH溶液浸泡96 h后依旧光亮,没有锈蚀点。     

电泳–电沉积制备镍–钴–氧化铝纳米复合镀层及其性能

先采用电泳沉积工艺在紫铜表面均匀沉积粒径为20 nm的Al2O3薄膜,然后通过电沉积在Al2O3沉积层表面得到Ni–Co合金,最终得到具有较高Al2O3含量的Ni–Co–Al2O3纳米复合镀层。采用扫描电镜和能谱仪分析了复合镀层的微观形貌和组成,并研究了镀层中Al2O3含量对镀层显微硬度和耐磨性的影响。结果表明,通过改变电泳沉积时间可制得Al2O3含量不同的Ni–Co–Al2O3复合镀层。Ni–Co–Al2O3复合镀层的综合性能优于Ni–Co合金镀层和Ni–Al2O3复合镀层。当复合镀层中纳米Al2O3粒子的体积分数约为30%(电泳沉积时间120 s)时,镀层组织致密,显微硬度较高,耐磨性最佳。     

电镀钨合金抽油杆耐硫化氢腐蚀研究

采用直流电镀法,在30CrMo抽油杆表面分别制备了单层Fe–Ni–W、Ni–W–P、Ni–W和双层Fe–Ni/Ni–W–P合金。室温下,将上述镀覆了钨合金的抽油杆浸泡在饱和H2S水溶液中30d,采用失重法、扫描电镜、X射线衍射等方法对其耐腐蚀进行了分析。结合阳极极化曲线测量,探讨了双层Fe–Ni/Ni–W–P镀层的耐蚀机理。实验结果表明:钨合金镀层使抽油杆的耐腐蚀性得到了显著提高,从而可延长其使用寿命。双层Fe–Ni/Ni–W–P合金镀层的耐蚀性最好,Fe–Ni层与Ni–W–P层之间的电势差达到了150mV,起到很好的保护作用。     

电沉积铜–镍–锡–聚四氟乙烯复合镀层及其性能

针对Cu–Ni–Sn合金自润滑性能差的问题,向Cu–Ni–Sn合金镀液中加入聚四氟乙烯(PTFE)乳液,采用电沉积法在45钢表面制备了Cu–Ni–Sn–PTFE复合镀层。镀液组成和工艺条件为:氰化亚铜35 g/L,游离氰化钠10 g/L,锡酸钠10 g/L,氯化镍15 g/L,蛋氨酸20 g/L,甲基磺酸18 g/L,60%PTFE乳液5~15 m L/L,电流密度1 A/dm~2,温度50~60°C,pH 10,时间2 h。考察了镀液PTFE含量对镀层的耐磨性、显微硬度、结合力、PTFE含量以及外观的影响,表征了Cu–Ni–Sn–PTFE复合镀层的形貌、结构和成分。随着镀液PTFE含量的升高,镀层的耐磨性改善,但显微硬度和结合力下降,厚度和PTFE含量则先升后降。镀液中PTFE的最佳添加量为10 m L/L,此添加量下所得Cu–Ni–Sn–PTFE复合镀层的综合性能最佳。     

二硫化钼含量对铁-二硫化钼复合电镀层性能的影响

为了提高Fe镀层的耐磨性，向镀铁液中添加不超过40 g/L的纳米MoS₂颗粒，通过电沉积得到Fe–MoS₂复合镀层。利用金相显微镜、扫描电镜、能谱仪、显微硬度计、热震试验及摩擦磨损试验研究了MoS₂颗粒质量浓度对Fe–MoS₂复合镀层微观形貌、元素组成、显微硬度、结合力及耐磨性的影响。结果表明，Fe–MoS₂复合镀层的结合力良好，表面微裂纹比Fe镀层多，显微硬度高于Fe镀层，耐磨性优于Fe镀层。当MoS₂质量浓度为30 g/L时，Fe–MoS₂复合镀层的显微硬度最高，耐磨性最佳。     

中温酸性纳米化学复合镀镍-磷-石墨工艺

采用化学复合镀方法在45钢基体上镀覆Ni–P–石墨复合镀层,通过改变镀液的pH、搅拌速度、表面活性剂和石墨(40nm)的用量,优化了化学复合镀工艺,确定了较优的工艺参数:石墨粒子240mg/L,表面活性剂(十二烷基苯磺酸钠)0.05g/L,pH5.0,搅拌速率300r/min。以扫描电镜和能谱分析了优化工艺获得的Ni–P–石墨复合镀层的表面形貌及组成,测试了镀层性能。结果表明,Ni–P–石墨复合镀层中石墨分散均匀,Ni和P的质量分数分别为93.78%和6.22%。与Ni–P合金镀层相比,Ni–P–石墨复合镀层的耐蚀性明显提高,其耐磨性提高了5倍,热处理后复合镀层的显微硬度最大可以达到1336.3HV。     

激光诱导ABS塑料表面电磁屏蔽功能线路的制备

通过激光诱导化学镀技术实现了ABS塑料表面电磁屏蔽功能电子线路的制备。将10 g/L NiSO_4·6H_2O+40 g/L NaH_2PO_2·H_2O混合溶液涂覆于铜线路表面,利用激光雕刻机以0.1 mm的光斑直径和5 mm/s的扫描速率对预先用类似方法在ABS塑料上制备的铜线路镀层进行扫描活化,然后化学镀Ni–P–Cu合金。采用扫描电镜、能谱仪、法兰同轴测试系统、四探针测试仪和热循环试验对线路的表面形貌、组成、电磁屏蔽性能、电阻率和结合力进行表征。结果表明,活化后的线路表面附着一层20 nm左右的Ni微粒,所得Ni–P–Cu合金镀层的电磁屏蔽效能接近80 dB,屏蔽功能线路的电阻率为3.72×10~(-8)?·m,结合力良好。     

高频脉冲电镀制备镍–钴/碳化硅复合镀层

采用高频脉冲电沉积法在不锈钢板上制备Ni–Co/SiC复合镀层。研究了镀液中SiC含量、脉冲频率、占空比以及平均电流密度对复合镀层中Si含量的影响,得到的较佳工艺参数为:纳米SiC 8 g/L,脉冲频率60 kHz,平均电流密度3～4 A/dm2,占空比0.32,温度40°C,pH 4.0～5.0,时间60 min。对比研究了较佳工艺下制备的Ni–Co/SiC和Ni–Co镀层的表面形貌和相结构。结果表明,Ni–Co/SiC复合镀层的表面比Ni–Co合金镀层更细致均匀,SiC具有细化镀层晶粒的作用。     

碳纤维复合吸波涂层材料的性能影响研究

以水性聚氨酯为基,碳纤维为填料,制备了碳纤维复合吸波涂层材料。采用扫描电镜、差示扫描量热仪、傅里叶红外光谱仪、X射线衍射仪和矢量网络分析仪对碳纤维复合吸波涂层材料的结构与性能进行了测试和表征。实验结果表明:碳纤维复合吸波涂层材料为碳纤维和水性聚氨酯的物理结合,随着碳纤维含量的增加和厚度的增大,碳纤维复合吸波涂层材料的反射率峰值均向低频移动,当碳纤维含量为0.8%,涂层厚度为1.2 mm时,碳纤维复合吸波涂层的反射率峰值达到-6.01 dB,小于-5 dB的带宽为4.2 GHz,涂层面密度为1.02kg/m~2。     

Ni-Si3N4纳米复合镀层研究

将Si3N4纳米粒子加入电镀镍的基础镀液中,在碳钢上制备了Ni–Si3N4复合镀层。扫描电镜观察表明,复合镀层的表面晶粒细小致密。能谱分析结果表明,镀层表面以Ni元素为主,且含有少量的Si和N。随着镀液中纳米Si3N4粒子含量的增加,镀层的显微硬度升高。热震法和划痕法实验表明,镀层与基体结合良好。     

The chemistry, morphology, topography of titanium carbide modified carbon fibers

Titanium carbide coatings were successfully applied on carbon fibers using reactive chemical vapor deposition approach. Chemistry, morphology, and topography of the TiC modified carbon fibers have been studied by scanning electron microscopy/energy dispersive spectroscopy, atomic force microscopy, and X-ray diffraction analysis. Uniform, adherent, crack-free and non-bridging coatings were obtained. After application of the TiC coating on carbon fibers, relief becomes more smooth and uniform. This is confirmed by decrease of the roughness parameter and the average height value of relief, as well as by decrease of scatter of measured heights. The coating consists of radially oriented crystals with high aspect ratio. Crystals are aligned in rows which are parallel to fiber axis. An increase in the tensile strength has been achieved by introducing the TiC coating on carbon fiber, the average strength and the Weibull modulus parameters were 2.55 GPa and 4.36 GPa, respectively. The obtained results can be useful for the predictive design of the well-matched interphase zone for composite materials reinforced by the TiC-coated carbon fibers.     

Plasma etching and plasma polymerization coating of carbon fibers. Part 2. Characterization of plasma polymer coated carbon fibers

Unsized AS-4 carbon fibers were subjected to RF plasma etching and/or plasma polymerization coating in order to enhance their adhesion to vinyl ester resin. Ar, N₂ and O₂ were utilized for plasma etching, and acetylene, butadiene and acrylonitrile were used for plasma polymerization coating. Etching and coating conditions were optimized in terms of plasma power, treatment time, and gas (or monomer) pressure by measuring the interfacial adhesion strength. Interfacial adhesion was evaluated using micro-droplet specimens prepared with vinyl ester resin and plasma etched and/or plasma polymer coated carbon fibers. Surface modified fibers were characterized by SEM, XPS, FT-IR, α-Step, dynamic contact angle analyzer (DCA) and tensile strength measurements. Interfacial adhesion between plasma etched and/or plasma polymer coated carbon fibers and vinyl ester resin was reported previously (Part 1), and characterization results are discussed is this paper (Part 2). Gas plasma etching resulted in preferential etching of the fiber surface along the draw direction and decreased the tensile strength, while plasma polymer coatings altered neither the surface topography of fibers nor the tensile strength. Water contact angle decreased with plasma etching, as well as with acrylonitrile and acetylene plasma polymer coatings, but did not change with butadiene plasma polymer coating. FT-IR and XPS analyses revealed the presence of functional groups in plasma polymer coatings.     

2mm短切碳纤维吸波涂层的制备与吸波性能

基于雷达吸波涂层薄、轻、宽、强的要求,以2 mm短切碳纤维为吸收剂,水性聚氨酯为基体树脂,制备了碳纤维吸波涂层,将芳纶纸蜂窝与碳纤维吸波涂层进行匹配,并采用矢量网络分析仪测试了涂层的吸波性能。结果表明,单层碳纤维吸波涂层在厚度较薄时吸波性能较差,添加匹配层后性能有所改善。将不同碳纤维含量的吸波涂层与芳纶纸蜂窝进行匹配,制备了多层匹配碳纤维吸波涂层,涂层的吸收强度和有效吸收带宽均得到明显提升,通过调整碳纤维涂层和芳纶纸蜂窝的匹配方式,复合涂层在4.1~13.6 GHz频率范围内均能实现有效吸收。     

Design and optimization of the coating thickness on chopped carbon fibers and sintering temperature for ZrB2-SiC-Cf composites prepared by hot pressing

Interface designation and low-temperature densifying were expected to inhibit the performance attenuation of fiber in the preparation of ceramic matrix composites. Nevertheless, the optimization of interface thickness and sintering temperature were still rarely investigated systematically. Herein, the performance of carbon fiber varied with coating thickness and the heat-treat temperatures were investigated by quantitatively. The tensile strength of carbon fibers degraded dramatically (≥30%) when coating thickness above a critical value. A larger dimension and ordered graphite crystallite structure resulted in the severe performance deterioration of carbon fibers as the sintering temperature exceeding 1500 ℃. The PyC coatings with an appropriate thickness acted as a critical role of changing the fracture mode of the ZrB₂-SiC-C_f and noticeably increased the fracture strain of the composite. The regular trend provided a general design strategy in construction of ZrB₂-SiC-C_f composite with optimal properties and could be extended to other ceramic matrix composites.     

Effects of carbon nanotube content on adhesion strength and wear and corrosion resistance of epoxy composite coatings on AA2024-T3

The effects of multiwalled carbon nanotube (MWCNT) content on the adhesion strength and wear and corrosion resistance of the epoxy composite coatings prepared on aluminum alloy (AA) 2024-T3 substrates were evaluated using atomic force microscopy (AFM), blister test, ball-on-disk micro-tribological test and electrochemical impedance spectroscopy (EIS). The adhesion strength of the epoxy composite coatings improved with increasing MWCNT content. Increased MWCNT content also decreased the friction coefficient and increased the wear resistance of the epoxy composite coatings due to improved solid lubricating and rolling effects of the MWCNTs and the improved load bearing capacity of the composite coatings. Finally, EIS indicated that increased MWCNT content increased the coating pore resistance due to a decreased porosity density, which resulted in an increase in the total impedance of the coated samples.     

用杜仲胶/碳纳米管改性环氧树脂制备导电防腐涂料及其性能

以杜仲胶(EUG)和环氧树脂(E-51)为涂层基质、碳纳米管为导电填料制备了导电防腐涂料,考察了 EUG用量对复合涂层导电性和耐腐蚀性的影响.采用差示扫描量热仪和动态热机械分析仪研究了复合涂层的热性能,用四探针测试仪研究了导电性能,分别通过电化学阻抗谱及盐雾测试和附着力测试研究了耐腐蚀性和附着力.结果表明,当EUG用量...     

钛合金表面阳极化处理对钛合金／复合材料胶接性能的研究

通过碱性阳极化方法NaTESi处理钛合金,碳纤维复合材料胶接试件中钛合金的表面。主要研究了阳极化前碱洗酸洗、阳极化过程中的电压、温度、时间以及该方法与喷砂法结合对处理后的钛合金胶接试件胶接性能的影响。结果表明：钛合金阳极化前的碱洗酸洗能提高钛合金／碳纤维复合材料胶接试件的粘接强度,阳极化过程中,电压在8-12V,温度在15。25％,时间在15．25min之间时处理出的钛合金所制成的胶接试件有较好的湿热耐久性能;喷砂法与NaTESi阳极化法配合处理钛合金表面,可使钛合金,碳纤维复合材料胶接试件湿热耐久性能得到进一步的提高。     

镍基合金镀层及其复合镀层磨蚀特性的研究

本文探讨了镍基合金镀层、镍基合金复合镀层及对比镀层的磨蚀特性.结果表明非晶态镍基合金及其复合镀层具有最佳抗磨蚀性能.