复合电沉积制备镍基纳米碳管复合材料的方法

一种复合电沉积制备镍基纳米碳管复合材料的方法，以能够沉积镍或者镍合金的各种常用镀液体系作为基础镀液，将经过常规钝化除杂处理的纳米碳管作为添加剂进入其中，构成能够沉积金属基纳米碳管复合材料的新型复合镀液，然后按照一般电镀／化学镀的操作方法，借助通电或者自发化学反应过程促使镍或者镍合金在一定的基体上沉积的同时，使纳米碳管与金属共沉积，制备镍基或者镍合金基纳米碳管复合材料。     

熔融纺丝方法制备纳米碳管/聚丙烯复合纤维及其拉伸性能

采用传统的熔融纺丝技术大量制备了定向性良好的纳米碳管／聚丙烯复合纤维。扫描电镜观察证实了纳米碳管在纤维里的定向性以及分散性都得到了较大的改善。通过拉伸实验测试了纳米碳管／聚丙烯复合纤维的力学性能，采用weibull统计分析发现纳米碳管的添加显著提高了复合纤维的拉伸强度，当添加纳米碳管的质量分数达到3％时，纤维强度最高，达到61MPa，超过聚丙烯纤维强度120％。复合纤维拉伸断口的形貌特征也证实了纳米碳管添加对复合纤维拉伸性能影响存在临界现象。     

单壁纳米碳管/聚酰亚胺复合材料的制备及导电特性

采用熔融聚合法和反复机械拉伸法,制备出定向排列单壁纳米碳管(SWNTs)/聚酰亚胺(PI)复合材料。研究了纳米碳管在复合体中的排列和分散情况。讨论了填充纳米碳管的质量分数对复合材料导电性能的影响,发现SWNTs填充质量分数很少时,复合体系呈现渗流行为,表现出良好的导电性和各向异性,其电导率随着填充纳米碳管的质量分数增加,电导率增大,而且在其拉伸方向比其垂直方向显示出较高的电导率,沿着其拉伸方向的渗流阈值比其垂直方向要低,说明单壁碳纳米管在复合物材料中呈现出良好的排列和均匀分散。     

纳米碳管-(Ni-P)复合材料制备及性能

采用化学复合镀的方法,在45#钢衬底上制备纳米碳管(CNTs)-(Ni-P)复合材料。探讨了该复合材料的制备技术及工艺条件,通过对实验结果的观察和分析,确定了制备CNTs-(Ni-P)复合材料的最佳工艺条件。利用透射电镜(TEM)观察纳米碳管的结构;用扫描电镜(SEM)观察纳米碳管形貌及其在复合材料中的分布;利用原子力显微镜(AFM)观察复合材料表面的粗糙度。同时还对纳米碳管复合材料的耐磨性进行了初步的测试。实验结果表明,该复合材料的耐磨性明显好于未镀及单纯镀镍材料。     

"Y"形、竹节形与直纳米碳管拉伸力学特性的有限元分析

采用基于直纳米碳管拉伸曲线与单元"死亡"技术的非线性有限元方法模拟了"Y"形、竹节形与直纳米碳管的拉伸失效过程.对比并讨论了"Y"形、竹节形纳米碳管与直碳管的拉伸力学性能.研究表明,本文的非线性有限元方法能够有效模拟纳米碳管的拉伸力学特性;拉伸"Y"形、竹节形碳管的失效发生在其粗管与细管过渡的"应力集中"部位;"Y"形、竹节形碳管的抗拉强度与韧性明显低于直碳管;然而,"Y"形、竹节形碳管的弹性模量与直碳管相当.     

分叉纳米碳管与直纳米碳管拉伸力学特性的分子动力学研究

采用分子动力学方法,模拟了分叉纳米碳管与直纳米碳管的拉伸过程,对比、分析了分叉纳米碳管与直纳米碳管的拉伸力学性能。研究表明,分叉纳米碳管拉伸时的屈服与断裂发生在其粗管与细管过渡处,其抗拉强度与韧性分别低于直纳米碳管24％和17％,然而,其弹性模量却与直纳米碳管相当。     

定向纳米碳管表面有机和无机膜的制备

在AAO ( 阳极氧化铝 ) 模板上的定向纳米碳管表面制备了有机和无机膜。一种是采用真空蒸镀的方法沉积酞菁铜 ( CuPc ) 有机膜,另一种是用电沉积的方法在碳管表面沉积钴金属膜。对所镀的膜层进行了扫描电镜和透射电镜观察,结果表明:在纳米碳管表面获得了均匀的有机和无机涂层。它们的区别是蒸镀方法使纳米碳管背面不能获得涂层,而电镀方法能在整根纳米碳管上获得均匀涂层。      

结构稳定、散热量大的柔性纳米碳管@热解炭复合纸的制备（英文）

通过在纳米碳管纸上沉积热解炭层的方法来提升其结构稳定性并保持其优异的性能。这种纳米碳管@热解炭复合纸可以被切割成任意形状而无开口式破裂。在500次往复弯曲后,其内部结构仍保持完整。弯折前后,复合纸的拉伸强度从8.58 MPa提升至11.41 MPa,这是因为内部纳米碳管取向更加趋于一致。复合纸的热扩散率和散热量几乎保持不变,并接近同尺度的铜箔,这归功于纳米碳管增强的热解炭层及内部纳米碳管网络在变形过程中没有损伤。故这种复合纸有望作为一种轻质柔性的散热材料。     

纳米碳管／聚酰亚胺复合材料制备与性能研究

利用纳米碳管的N甲基吡咯烷酮分散液，通过改变纳米碳管表面的性质和薄膜的制备条件，成功地制备了一系列均匀的纳米碳管，聚酰亚胺薄膜。研究结果表明，添加酰氯化后的纳米碳管到聚酰亚胺中可以改善聚酰亚胺的拉伸性能，而对聚酰亚胺的热稳定性和光学性质没有明显的影响。当添加1．0％的纳米碳管时，与纯PI相比复合材料的弹性模量增加了25．6％，拉伸强度增加了31．0％，断裂伸长率增加了7．6％。     

纳米碳管、聚合富勒烯链的拉伸特性与电子结构

采用分子动力学方法对C240纳米碳管、线形及花生壳状4C60富勒烯链等三种C240异构分子的拉伸进行了模拟;使用PM 3半经验量子化学方法对各拉伸C240分子的电子结构进行了计算。根据计算结果,讨论了三种C240分子拉伸力学特性的差异,以及前线分子轨道能级在压缩过程中的变化。研究结果表明,三种C240分子的承载能力依次为:纳米碳管>花生壳状4C60>线形4C60,承受变形能力依次为:线形4C60>花生壳状4C60>纳米碳管;C240碳管具有最好的化学稳定性,线形4C60分子的稳定性最差;拉伸变形后的三种C240分子的LUM O与HOM O能隙均减小,化学活性均增加。     

Investigation of the mechanical properties of the Ni–P–CNTs coated copper composite materials: Experiments and modeling

Recent studies on the mechanical properties of nickel–phosphorous–carbon nanotubes (Ni–P–CNTs) coated copper composite materials have shown surprising results. Their Young’s modulus and tensile strength cannot reach the theoretical values, even falling below those of copper, and the Young’s modulus decreases with the increment of CNT concentrations. Materials used in those studies were prepared through electroless composite plating process, with the Ni–P–CNTs composite electrolessly deposited on the copper substrate. In the present study, however, it is shown that the Young’s modulus and the tensile strength do increase significantly with the increment of the CNT concentrations without activating the CNTs. A composite method of Voigt model and a random distributed discontinuous fiber model is applied to obtain the equivalent Young’s modulus of the composite, which agrees very well with the experimental data.     

Effect of carbon nanotubes and their dispersion on electroless Ni–P under bump metallization for lead-free solder interconnection

Electroless Ni–P under bump metallization (UBM) has advantages of even surface, low cost and simplicity to deposit, but their mechanical strength, corrosion resistance and stability still face challenges under high soldering temperature. Incorporating carbon nanotubes (CNTs) into electroless Ni–P UBM might be expected to provide Ni–P–CNT composites with high mechanical strength and stability. Ni–P–CNT composite coatings as well as Ni–P coatings were fabricated by electroless plating process. In order to homogeneously disperse CNTs in composite coatings, acid pre-treatment and surfactant dispersant were introduced. During composite electroless plating, the ultrasonic agitation was also employed. In this study, scanning electronic microscopy (SEM) was used to observe the morphology and the CNTs were proved to be uniformly distributed in Ni–P–CNT coatings by SEM and atomic force microscopy. It was verified that the surface of the composite was quite smooth and continuous; CNTs are equably embedded in the matrix, which is advantageous for conductivity, mechanical strength and corrosion resistance. Shear tests were conducted to evaluate the effect of CNT reinforcement on the mechanical properties of joints, and the joints with CNT additions exhibited higher shear strength at different reflow cycles. Moreover, deposition mechanism of CNTs with Ni was analyzed and confirmed by transmission electron microscopy. Factors that affecting plating process was also discussed, and the optimum plating condition was suggested in this study.     

碳纳米管-Ti3AlC2/AZ91D复合材料的微观组织及力学性能

采用化学镀铜的方法对增强相碳纳米管(CNTs)和Ti₃AlC₂进行表面改性,热压烧结制备了CNTs-Ti₃AlC₂/AZ91D复合材料,研究了其微观组织和力学性能的变化及增强机制。结果表明:CNTs-Ti₃AlC₂/AZ91D复合材料内部主要物相为CNTs、Ti₃AlC₂、Mg和Al₁₂Mg₁₇,增强相均匀分布在基体内,在增强相与基体的界面处存在U相(MgAlCu),使二者界面结合良好。当增强相CNTs 和Ti₃AlC₂含量分别为1wt%和25wt%时,较镁合金AZ91D,CNTs-Ti₃AlC₂/AZ91D复合材料的弹性模量、拉伸强度、屈服强度和延伸率分别提高了120.30%、25.72%、126.50%和36.84%,弯曲强度和压缩强度分别为337.92 MPa和436.27 MPa。CNTs-Ti₃AlC₂/AZ91D复合材料的断裂方式表现为脆性断裂,其强化机制主要为热配错强化、Orowan强化和细晶强化机制。      

Preparation and characterization of Ni-Cu-P/CNTs quaternary electroless composite coating

Ni-Cu-P/carbon nanotubes (CNTs) quaternary composite coatings were successfully obtained on low carbon steel matrix by electroless plating. The effects of CNTs concentration in the bath on the microstructure of the composite coatings, CNTs content in the composite coatings and the hardness of composite coatings before and after heat treatment at 400 °C have been studied. In addition, the corrosion resistance of Ni-Cu-P/CNTs composite coatings was evaluated by anodic polarization curves in 3.5 wt.% NaCl solution at room temperature. It was noted that the CNTs concentration remarkably influenced the surface morphology of the coatings. With increasing CNTs concentration, both the CNTs content in the composite coatings and the hardness of composite coatings increased at first and then decreased. And the composite coatings after heat treatment provided higher hardness than the as-deposited coatings. The corrosion resistance of Ni-Cu-P/CNTs composite coatings is excellent compared with that of Ni-Cu-P coatings.     

Sn3.0Ag0.5Cu3.0Bi钎料对化学镀镍SiCp/6063Al复合材料真空钎焊接头组织和性能的影响

采用Sn3.0Ag0.5Cu3.0Bi软钎料对镀镍后的两种不同体积比SiC_p/6063Al复合材料进行真空钎焊。通过SEM、剪切试验等方法分析了化学镀镍后SiC_p/6063Al复合材料真空钎焊接头的显微组织以及保温时间对接头性能的影响。结果表明:两种不同体积比SiC_p/6063Al复合材料真空钎焊后的焊缝组织致密,钎料对镀镍复合材料的润湿性良好;在270℃、保温35min的钎焊工艺下,钎焊接头的剪切强度最大值为38.3 MPa;钎料中的Sn、Cu元素能够与复合材料表面的Ni层发生化学反应,实现钎料与母材的冶金结合;镀镍后SiC_p/6063Al复合材料真空钎焊接头断裂形式为韧性断裂为主的混合断裂,断裂主要发生在钎料内部,部分发生在镀镍层与钎料的结合处。     

Ni-P化学镀层对20CrMo钢腐蚀疲劳强度的影响

对比研究了不经热处理和经热处理的Ｎｉ－Ｐ化学镀层对抽油杆用２０ＣｒＭｏ钢的腐蚀疲劳强度的影响。结果表明，不经热处理的Ｎｉ－Ｐ化学镀层明显提高了钢基体的腐蚀疲劳强度，但却降低了基体的疲劳强度。经热处理后，腐蚀疲劳强度有所下降。Ｎｉ－Ｐ化学镀层中的磷含量的电子探针测量和镀层的Ｘ射线衍射分析结果表明，Ｎｉ－Ｐ化学镀层为非晶态结构。此外，还用扫描电镜观察分析了疲劳断口。     

Si元素对碳纳米管增强铝基复合泡沫组织与性能的影响

针对金属基复合材料,添加合金元素是提升其综合性能的有效途径.本文通过高能球磨和填加造孔剂法,制备了添加Si元素的碳纳米管(CNTs)增强铝基(CNTs/Al-Si)复合泡沫,通过准静态压缩实验测试其压缩性能和吸能性能,进一步研究烧结温度和不同Si元素含量对CNTs/Al-Si复合泡沫微观组织、压缩性能和吸能性能的影响,...     

碳纳米管增韧超细Ti(C|N)基金属陶瓷

Ti(C,N)基金属陶瓷的低韧性限制了其广泛应用于切削刀具领域。为探究碳纳米管对超细Ti(C,N)基金属陶瓷断裂韧性的影响,采用化学镀工艺在碳纳米管表面镀Ni,采用粉末冶金法真空烧结制备了不同碳纳米管含量的超细Ti(C,N)基金属陶瓷。研究了不同含量镀镍和未镀镍的碳纳米管对Ti(C,N)金属陶瓷组织和断裂韧性的影响。扫描电镜照片表明 , 添加CNTs后,组织中出现无芯晶粒及微孔洞。压痕法测试断裂韧性的结果表明,纳米管的加入使超细Ti(C,N)金属陶瓷的断裂韧性提高 29. 4 %～62. 7 % , 碳纳米管增韧机制为裂纹偏转和桥接增韧、无芯晶粒增韧及微孔洞增韧。此外,随着碳纳米管含量的增加,超细CNTs/Ti(C,N)金属陶瓷复合材料的相对密度和硬度均有轻微下降。添加镀镍和未镀镍碳纳米管对超细Ti(C,N)金属陶瓷都具有很好的增韧作用。     

碳纳米管的特性及其高性能的复合材料

碳纳米管具有超强的力学性能、极高的纵横比和独特的导电特性,是制备复合材料的理想形式。评述了目前碳纳米管复合材料的制备及其应用研究的动态。用化学镀方法制备的镍基碳纳米管复合镀层比传统的复合镀层具有更高的耐磨性能,结构为非晶态。讨论了复合镀制备金属基碳纳米管复合镀层的优越性及应用。用原位聚合法合成了导电聚苯胺-碳纳米管的复合材料,可以作为电池和电化学超级电容器的电极材料。      

The effect of saccharin addition on the mechanical properties and fracture behavior of electroless Ni–Cu–P deposit on Al

In a previous study, the effects of additive saccharin on internal stress, diffusion, and crystallization behaviors of electroless Ni–Cu–P deposits on Al were examined. In this study, tensile test results and microhardness measurements were used to investigate the effect of additive saccharin on the mechanical properties and fracture behavior of electroless Ni–Cu–P deposits on Al. An increase in the saccharin content of the plating solution from 0 to 12 g/L results in nodule growth and void elimination in the deposits. The denser nodules in the deposit also cause a decrease in the tensile stress and reveal the effect of ΔTCE on compressive stress generation. Consequently, the mechanical properties of Ni–Cu–P/Al deposits in terms of microhardness, yield strength, modulus of elasticity, and ultimate tensile strength were improved. The fracture behavior of the deposit changes from transnodular to internodular when the saccharin addition is above 4 g/L.