碳纤维表面沉积铜工艺及其参数影响机理研究

碳纤维增强铝基复合材料因具备碳纤维与铝的优良性能,高比强度、比模量,良好的热稳定性及性能与功能的可设计性等特点,在光机结构、航空航天结构件等方面具有广阔的应用前景。为了改善碳纤维与铝基体的界面润湿性能和抑制基体与纤维的界面反应,需要在碳纤维表面沉积铜界面层。本文通过对传统电镀装置的改进,采用了超声振荡分散的电镀装置在碳纤维表面沉积了铜界面层,通过对电镀前碳纤维的预处理、电镀液成分的优选调配,解决了碳纤维铜界面层沉积过程中因纤维束丝难以分散而出现的“夹心”问题(束丝内部纤维难以沉积或不能均匀沉积);在此基础上,详细研究了电镀液添加剂、电镀液PH值、电镀时间等工艺参数对铜界面层的微观结构、铜界面层质量及影响机制,为制备碳纤维增强铝基复合材料提供了一定的技术支持。     

连续Cf/Al复合材料板双辊铸轧制备及力学性能研究

本文利用电镀工艺制备了表面镀镍碳纤维,通过双辊铸轧短流程成型工艺成功制备了连续碳纤维增强铝基（Cf/Al）复合材料板,研究了浇注温度对铸轧复合材料板的微观组织、界面特征、断口形貌和力学性能的影响。结果表明,浇注温度为963～983K,轧制速度为2.7m/min,辊缝为2.0mm的条件下可制备出表面平整、无明显表面缺陷的Cf/Al铸轧复合材料板;其中,浇注温度为973K时,碳纤维与铝基体之间界面结合良好;纤维表面金属镍层明显改善了碳纤维与铝基体之间的浸润性,镍镀层还有效抑制了Al4C3脆性相的产生,使Cf/Al复合材料板力学性能大幅提升,其中浇注温度973K铸轧的Cf/Al复合材料板抗拉强度比初始的38.2MPa提高了87.4%。     

短碳纤维增强铝基复合材料的挤压浸渗工艺

采用挤压浸渗法制备了短碳纤维增强铝基复合材料 ,研究了浸渗压力、铝液浇注温度、纤维预热温度等对复合材料组织的影响。结果表明 :合适的工艺参数为铝液浇注温度 740～ 80 0℃ ,预制块预热温度 35 0～ 40 0℃ ,浸渗压力 2～ 5MPa;在氩气保护下 ,无须对碳纤维表面进行涂层处理 ,可获得组织均匀的铝基复合材料。加入Al2 O3 颗粒可以改善纤维分布的均匀性     

Fabrication of PyC/SiC Compound Coating on Carbon Fiber Preform and Its Effect on the Properties of Cf/Al Composite

为改善碳纤维与熔融铝合金间的润湿性、减小界面反应程度,采用化学气相沉积（CVD）法在碳纤维预制体表面沉积制备了PyC/SiC复合涂层,利用真空吸渗挤压浸渗工艺制备了Cf/Al复合材料。研究了沉积参数对碳纤维表面涂层的影响,并通过复合材料微观组织分析及材料机械性能测试来反映涂层对Cf/Al复合材料的浸渗质量和性能的影响规律。结果表明：沉积温度对涂层沉积速率影响较大,通过选择合适的沉积温度或者沉积时间,可在碳纤维表面得到厚度均匀的PyC/SiC复合涂层。碳纤维预制体表面涂层的存在可使其与基体合金润湿性良好、界面结合强度适中,形成合适的界面结合状态,有效提高浸渗质量和复合材料性能;并且当PyC涂层、SiC涂层厚度分别为0.068、0.257 μm时,复合材料性能改善效果最佳     

镍铝材料状态对火焰喷涂层组织结构和性能的影响

针对煤矿机械液压支柱热喷涂修复中涂层结合强度低的实际,研究了在27SiMn钢基体上火焰喷涂新研制的镍铝合金丝制备镍铝涂层,并与火焰喷涂镍包铝粉末、镍铝复合丝制备的镍铝涂层在组织结构、表面形貌、结合强度等方面进行了比较分析.结果表明,镍铝合金丝制备的涂层与基体之间主要为冶金结合,结合强度比镍包铝粉末涂层提高46.8％,比镍铝复合丝涂层提高8％,涂层组织结构致密,气孔率低、质杂少.     

碳纤维表面SiO2涂层的制备及其在镁基复合材料中的应用

利用Sol-Gel方法,通过优化溶胶的配置、纤维提拉过程和干燥烧结等工艺过程,在碳纤维表面制备出均匀的、无裂纹的SiO2涂层.采用SEM、XPS和TEM表征了碳纤维表面SiO2涂层的结构、形貌、元素分布以及涂层碳纤维/镁基体的界面结构.结果表明,涂覆SiO2的碳纤维,抗氧化能力提高,拉伸性能略有降低,但与镁基体复合后其拉伸强度降低了20%.SiO2涂层改善了Mg对碳纤维的润湿能力,有效地促进了熔融Mg液对碳纤维的浸渗.     

碳纤维预制体表面PyC/SiC复合涂层制备及其对C_f/Al复合材料性能的影响（英文）

为改善碳纤维与熔融铝合金间的润湿性、减小界面反应程度,采用化学气相沉积(CVD)法在碳纤维预制体表面沉积制备了Py C/Si C复合涂层,利用真空吸渗挤压浸渗工艺制备了Cf/Al复合材料。研究了沉积参数对碳纤维表面涂层的影响,并通过复合材料微观组织分析及材料机械性能测试来反映涂层对Cf/Al复合材料的浸渗质量和性能的影响规律。结果表明:沉积温度对涂层沉积速率影响较大,通过选择合适的沉积温度或者沉积时间,可在碳纤维表面得到厚度均匀的Py C/Si C复合涂层。碳纤维预制体表面涂层的存在可使其与基体合金润湿性良好、界面结合强度适中,形成合适的界面结合状态,有效提高浸渗质量和复合材料性能;并且当Py C涂层、Si C涂层厚度分别为0.068、0.257μm时,复合材料性能改善效果最佳。     

铝合金表面喷射镀镍涂层的微观组织与力学性能研究

采用喷射电镀技术在铝合金表面制备喷射镀镍涂层,研究其表面微观组织和力学性能。结果表明,表面预处理对喷射镀镍涂层与铝合金基体的结合强度有较大影响,采用浸锌镍处理后的镀镍涂层与基体的结合强度最高。     

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.     

含Cu界面层碳纤维增强铝基复合材料制备工艺及其力学性能研究

为了改善碳纤维与Al基体的润湿性和抑制Al基体对碳纤维的反应腐蚀,采用电镀工艺结合超声辅助振荡分散法,在碳纤维表面制备了均匀、光滑、连续的Cu界面层。通过真空压力浸渗法制备了碳纤维增强铝基复合材料。微观组织结构分析表明,Cu界面层的引入,使得所制备的复合材料中碳纤维分散好、基体致密度高、Al熔体能很好地浸渗到碳纤维束丝中形成结合良好的碳纤维-基体界面;同时,Cu界面层的引入可以避免Al熔体对碳纤维的腐蚀。力学性能测试表明,与工业纯Al相比,当碳纤维的体积分数为8%时,材料的拉伸强度可以提高143%。断口分析表明,在拉应力作用下,碳纤维-基体复合区域的碳纤维在Al基体中发生了滑移或拔出,因此在碳纤维的滑移和拔出过程中裂纹扩展被抑制,从而大大提高铝基复合材料的强度。     

Mechanically assisted electroplating of Ni-P coatings on carbon steel

Ni-P coatings on carbon steel were plated by a mechanically assisted electroplating technique, which combines the conventional electroplating technique with mechanical ball-rolling. The mechanical ball-rolling was conducted by vibrating the sample being plated with glass balls on it. For comparison, the conventional Ni-P electroplating technique without mechanical ball-rolling was also used to deposit Ni-P coatings under the same coating conditions as those adopted in the mechanically assisted electroplating. The experimental results show that the Ni-P coatings electroplated with mechanical assistance were smoother in surface, thinner in thickness, harder in hardness, more positive in corrosion potential, and greater in polarization resistance in comparison with the Ni-P coatings electroplated without mechanical assistance. The mechanical ball-rolling made the Ni-P coatings crystallized in-situ during the coating process, thereby avoiding crystallization-induced cracking, which was observed during the crystallization of the amorphous Ni-P coatings electroplated without mechanical assistance. A simple phase transformation model explains qualitatively the Ni-P in-situ crystallization during the mechanically assisted electroplating.     

铝基厚梯度热障涂层制备工艺及性能研究

采用单一等离子喷涂法和超音速火焰喷涂与等离子喷涂复合喷涂法在铝质LY12基体上制蔷了总厚度分别为0.6mm、10mm和2．0mm的梯度热障涂层，并对基体界面处的涂层显微结构特征进行了金相组织和扫描电镜(SEM)观察，试验结果表明，采用复合喷涂法制备的2mm厚梯度热障涂层其抗拉强度得到显著提高．达到36MPa．其主要原因是采甩JP5000喷涂粘结底层很好的改善了铝基体与游层之间的界面结合强度。基体界面结合强度高低与两者的紧密接触程度有关。     

Process optimisation of non-cyanide Ag–PTFE metal matrix composite electroplating for threaded connections

Silver–polytetrafluoroethylene (PTFE) metal matrix composite coatings were deposited onto ANSI 304 stainless steel to assess the potential of using a novel nitrate–succinimide non-cyanide electroplating process to produce a corrosion resistant, self-lubricating composite coating. During this study, 32 different bath parameter sets derived from five variables were used to develop the non-cyanide electroplating process without the use of a surfactant or strike deposit. SEM/EDS as well as XPS microscopy were used to analyse the samples. In addition, the functional characteristics and adhesion strength of the coating were assessed using a bi-directional tribometer (to measure the coefficient of friction) and a pull-off test conducted on an Instron tensile test machine. The experimental results revealed that a friction coefficient of 0.23 was achievable (62% improvement over pure silver coating) where adhesion strength is not a primary consideration. For dry lubrication applications requiring high-coating adhesion strength, the maximum adhesion strength achieved for the Ag–PTFE composite coating was 2.5?MPa (44% reduction over pure silver coating) with a friction coefficient of 0.32 (47% improvement over pure silver coating).     

Q345R板材表面冷喷涂Al-Zn涂层的组织及性能研究

目的 研究添加元素Zn含量的变化对涂层的显微组织、孔隙率、硬度及涂层-基体间界面结合强度等的影响规律.方法 采用冷喷涂技术在Q345R板材表面制备性能优良的纯Al和Al-Zn复合涂层,通过扫描电子显微镜对涂层的形貌进行分析,通过维氏显微硬度计对涂层的力学性能进行表征,并揭示涂层与基体间的界面结合机理.结果 冷喷涂纯Al和Al-Zn复合涂层与Q345R钢基体的结合良好,界面处无明显的孔洞及裂纹.随着Zn含量的增加,复合涂层的致密度、硬度逐渐提高;纯Al和Al-20wt.％Zn复合涂层的界面结合强度相当,且失效断裂形式为典型的界面粘结断裂.随着添加元素Zn含量的增加,涂层与基体间的界面结合强度逐渐增大,Al-40wt.％Zn涂层的结合强度为35 MPa,且断裂方式由界面粘着断裂转变为以界面粘着断裂为主、涂层内部粘聚断裂为辅的复合失效模式.结论 以低温固态沉积为特点的冷喷涂技术可有效避免氧化、相变、热裂等高温导致的不利影响,在沉积过程中,随着添加元素Zn含量的增加,对涂层的夯实作用不断加强,提高了涂层的致密性,从而使涂层的力学性能得到改善.     

铝合金表面电弧喷涂Ag基涂层及其低温钎焊行为

在波导器件中,铝合金壳体较差的润湿性制约了其与微带电路板之间大面积、可靠低温钎焊连接. 通过电弧喷涂技术在5A06铝合金表面制备了厚度约为80 μm的Ag-15%Ni(质量分数)单一涂层和Ni-5%Al/Ag-15%Ni(质量分数)复合涂层,以提升Sn-Pb钎料在其表面的润湿性. 对比研究了两种涂层的显微结构、涂层界面结合性能、低温钎焊行为及钎焊接头剪切失效机制. 结果表明,涂层与铝合金基板间形成了良好的界面结合,并且两种涂层均具有较好的低温焊接性. 其中,Ag-15%Ni单一涂层与铝合金基板的结合强度为40 MPa,喷涂后铝合金基板与T2紫铜形成的钎焊接头抗剪强度为26 MPa. 相较而言,Ni-5%Al /Ag-15%Ni复合涂层展现出更佳的涂层结合强度(42 MPa)和钎焊接头抗剪强度(31 MPa).     

Fabrication and Characterization of Ni-Al_2O_3 Nano-Composite Coatings by Sediment Co-Deposition

Ni-Al2O3 nano-composite coatings were fabricated by sediment co-deposition (SCD) from Watt’s type electrolyte containing nano-Al2O3 particles without any additives. For comparison, Ni-Al2O3 nano-composite coatings were prepared by conventional electro-plating (CEP) under experimental conditions. Effects of process parameters, such as nano-Al2O3 concentration in plating solution, current density, stirring rate, and bath temperature, on nano-Al2O3 content in composite coatings were investigated. The distribut...     

LD31铝合金电刷镀SnPb钎料合金软钎焊

采用在LD31表面电刷镍阻挡层、铜改性层,将LD31铝合金的连接转化为铜的连接,在镀铜层的表面电刷镀SnPb钎料直接进行钎焊,通过开发低应力镀镍液和调整电刷镀工艺参数解决镍过渡层的裂纹问题,研究分析了镀层的显微结构及表面状态,焊缝的结构及元素分布,考察了焊接加热过程对镀层的影响。研究表明,通过在镀铜层表面直接刷镀SnPb钎料合金可以实现软钎焊连接,接头的抗剪强度可达20MPa,镀镍层、镀铜层钎焊后无裂纹、剥离等缺陷产生。     

Preparation and Characterization of Nickel-Coated Carbon Fibers by Electroplating

Electroplating technique was applied to coat carbon fibers with nickel. Before plating, the initial fibers were pretreated to improve the wettability in bath. The electroplating parameters were optimized to obtain high-quality nickel-coated carbon fibers, and the effects on plating were studied. The coated carbon fibers were characterized by SEM, XRD, and XPS. The coatings are uniform, smooth, bright, and adherent to carbon fibers not only along length but also along the diameter of the filaments, and mainly composed of pure nickel. Metal-carbon-oxygen bonds are present at the interface between nickel coatings and fibers, which provides the interfacial binding force. The results of performance tests showed that the nickel-coated fibers possess a good bonding strength not less than 78.5 kPa, and exhibit excellent oxidation resistance at high temperature. Compared with the initial fibers, the wettability with aluminum is also improved obviously.     

TC4合金表面Cu/石墨复合镀层的摩擦磨损行为

采用无氰电镀工艺在TC4合金表面制备了Cu/石墨复合镀层，研究了镀层的组织结构和摩擦磨损行为。结果表明，采用无氰电镀方法能够在TC4合金表面制备出组织致密且与基体结合紧密的Cu/石墨复合镀层，但增加镀层中石墨的含量会降低镀层与基体合金的结合强度，并导致硬度小幅下降。摩擦磨损实验结果表明，Cu/石墨复合镀层具有优良的摩擦磨损防护性能，归因于石墨有效降低了镀层的摩擦系数和磨损率；对镀层磨损形貌、磨损产物和摩擦系数的综合分析结果表明，纯铜镀层的摩擦磨损机制主要为犁削磨损、黏着磨损和剥层磨损，Cu/石墨复合镀层的磨损机制为轻微的削层磨损和疲劳磨损。     

Effects of Dissimilar Alumina Particulates on Microstructure and Properties of Cold-Sprayed Alumina/A380 Composite Coatings

In this study,alumina/A380 composite coatings were fabricated by cold spray.The influence of alumina particulates' morphology(spherical and irregular) and content on the deposition behavior of the coatings(including surface roughness,surface residual stress,cross-sectional microstructure and microhardness) was investigated.Results revealed that the spherical alumina mainly shows micro-tamping effect during deposition,which result in remarkable low surface roughness and porosity of the coatings.In addition,very low deposition efficiency and good interfacial bonding between the coating and the substrate were achieved.For irregular alumina particles,the embedding of ceramic particulates in the coating was dominant during deposition process,resulting in high retention in the final deposit.However,it showed limited influence on porosity,surface roughness and interfacial bonding of the deposit.The coatings containing irregular alumina particulates exhibited much higher microhardness than those containing spherical alumina due to the higher load-bearing capacity of deposited alumina.