搅拌法制备C／AI复合材料的界面问题

在碳纤维表面镀上一层金属铜镀层,用硼酸对其进行防氧化处理,采用机械搅拌法制取C／Al复合材料。利用扫描电镜、能谱分析和X射线衍射等手段对液态机械搅拌法制备的碳纤维增强铝基复合材料的界面微观结构进行了分析,结果表明,碳纤维表面镀铜,既可有效解决碳纤维与铝的润湿性问题,又可有效地阻挡碳纤维与铝的过度化学反应。硼酸作为保护剂,有效地解决了高温复合时镀铜层的氧化难题。Cu／Al界面生成大量的CuAl2金属间化合物,C-Cu／Al界面为混合界面：C／Cu界面和C／Al界面。     

碳纤维/环氧复合材料界面优化研究进展

从界面粘合理论、碳纤维表面改性、树脂基体改性等方面对碳纤维/环氧复合材料界面性能的研究进展进行了综述。表明界面对碳纤维/环氧复合材料充分发挥其优异性能起关键作用,其界面优化设计主要从碳纤维表面改性和树脂增韧改性入手,研究已取得一定进展;但亟需在界面作用机理、界面改善处理的工业化生产、纳米材料改性的技术难题等方面期待突破。     

碳纤维／PMR—15树脂复合材料的界面研究

本文研究了碳纤维/PMR-15树脂复合材料的界面结构与其性能的关系,破纤维表面采用了冷等离子体或冷等离子体接枝的处理,改善了复合材料界面的结合力,从而改进了材料的综合性能如力学性能等;论文工作中利用了透射电镜、扫描电镜、电子波谱等方法对界面的形貌及组成份进行了分析研究;采用计算机图象识别法使透视电镜的形貌图象变得更为直观与明显。     

含Si–O–C界面层的C/Si–C–N复合材料的抗氧化性能(英文)

为了研究利用Si–O–C界面层来提高碳纤维增强陶瓷基复合材料的抗氧化性能,利用化学气相浸渗和聚合物浸渗裂解工艺制备了以Si–O–C为界面的碳纤维增强Si–C–N陶瓷基复合材料（C/Si–O–C/Si–C–N）和无界面层的碳纤维增强Si–C–N陶瓷基复合材料（C/Si–C–N）。研究了C/Si–O–C/Si–C–N和C/Si–C–N在600、900℃和1 200℃空气环境中的氧化行为。结果表明：采用Si–O–C界面层后可提高复合材料的抗氧化性能;Si–O–C界面层较高的氧化抗力是碳纤维增强Si–C–N复合材料抗氧化性能提高的主要原因。     

高性能C/C复合材料制备工艺研究

对制备C/C复合材料的化学气相渗透工艺进行了系统的实验研究,着重分析了热解碳的沉积过程。研究表明,在化学气相渗透的初始阶段,热解碳主要在碳纤维表面沉积,并与碳纤维之间形成了界面结合;随后,热解碳的沉积继续填充碳纤维预制体内部的气孔。这一过程有助于缓解纤维与陶瓷基体之间的界面应力。研究表明,通过调节热解碳的沉积时间可以得到具有一定密度梯度的C/C复合材料。     

沸水对PI/CF复合材料界面作用机理的研究

研究了聚酰亚胺(PI)／碳纤维(CF)复合材料界面在沸水中的稳定性。结果表明,经沸水浸泡后的复合材料层间剪切强度和界面剪切强度均有所提高,且随水煮时间的延长而增大;试样断面观察表明,水没有对复合材料界面产生破坏作用,力学性能的变化与基体／纤维界面粘结的湿热稳定性有直接关系;沸水对界面的作用机理是,在PI／CF复合材料的界面区,树脂的水解使氢键的数量增加,形成了防水层,阻碍了水沿界面的侵入,同时水松驰了界面局部应力。     

Lanxide^TM法制备SICp／Al复合材料

Ｌａｎｘｉｄｅ＾ＴＭ技术是制备铝基复合材料的一种新方法,适于制备低孔隙率的ＭＭＣ。本文对利用该技术制备ＳｉＣｐ／Ａｌ复合材料进行了综述,阐述了Ａｌ对ＳＩｃＰ的润湿、渗透及界面反应等问题,并介绍了增强ＳｉＣｐ／Ａｌ的润湿、渗透及控制界面反应的方法。     

真空热压烧结制备高性能B4C/Al复合材料

B4C/Al复合材料因其优异的性能,受到了人们广泛关注.以Al粉和B4C粉体为原料,采用真空热压烧结法,在高于Al熔点温度时,制备出了碳化硼含量10wt%的铝基复合材料.研究结果表明:烧结温度为700 ℃,烧结压力为30 MPa,保温时间为45 min时,获得的B4C/Al复合材料力学性能最佳,其相对密度为98.2%,硬度为2.53 GPa,抗弯强度为350 MPa.球磨混料使Al颗粒表面生成少量Al2O3,在烧结过程中,Al2O3与B2O3发生固-液反应形成共融物,改善了B4C/Al之间的界面结合强度,从而获得力学性能优异的B4C/Al复合材料.     

集束效应对CFRC复合材料界面及力学性能的影响

碳纤维的分散均匀程度直接影响ＣＦＲＣ材料性能。碳纤维在水泥基体中分解性差，易集束或成团。本文用单丝、束丝拔出实验来考察集束效应对ＣＦＲＣ界面及力学性能的影响；结合Ｖ．Ｃ．Ｌｉ提出的束丝数学模型和实验结果对照；最后探讨了集束效应影响的机理。     

纳米粒子增强碳纤维复合材料界面性能的研究进展

详细介绍了纳米粒子改性碳纤维的方法、原理及其在增强碳纤维复合材料界面性能方面的研究进展,并指出了纳米粒子改性碳纤维复合材料界面性能存在的相应问题,为提高碳纤维复合材料界面性能的研究提供了参考。     

Properties and structure of MWNTs/cellulose composite fibers prepared by Lyocell process

Lyocell fiber is a new kind of regenerated cellulose fiber and expected to replace the Rayon fiber to be not only used in the textile field but also used in the fields of industry and aerospace after being modified. In this work, the multi‐walled carbon nanotubes (MWNTs)/Lyocell composite fibers were prepared under different draw ratios by dry‐wet spinning and their electrical properties, mechanical properties, and structure were investigated. It was found that an appropriate amount of MWNTs could be dispersed homogeneously in the Lyocell matrix and could improve the mechanical and thermal properties of composite fiber. The results of wide angle X‐ray diffraction (WAXD) showed that the MWNTs in the composite fiber almost aligned along the axis of the fibers and the orientation of MWNTs increased with the increasing draw ratio. Furthermore, it was found that more MWNTs content and lower draw ratio could improve the electrical conductance of the composite fiber. The composite fiber containing 5 wt % MWNTs has a volume conductivity of 8.8 × 10^?4 S/cm, which is five orders higher than that of pure Lyocell fiber. These results indicate that the MWNTs/Lyocell composite fiber has potential applications in the areas of precursor of carbon fiber and conductive fiber. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Multiwalled carbon nanotube/polyacrylonitrile composite fibers prepared by in situ polymerization

Multi‐walled carbon nanotubes (CNTs) were mixed with polyacrylonitrile (PAN) by in situ polymerization or by mechanically mixing. The mixtures were then wet‐spun into fibers, respectively. The effects of mixing method on the interfacial bonding between the components in the fibers and the properties of the fiber were investigated by Raman spectroscopy, TEM, SEM, and tensile strength testing. By in situ polymerization mixing, a thin layer of PAN molecules is observed to cover the surface of the CNT, which increases the diameter of CNT evidently. Results of Raman spectroscopy indicate that the layer of PAN molecules are strongly attached onto the surface of CNT through grafting polymerization, leading to strong chemical bonding between CNTs and PAN matrix in the obtained fibers. In contrast, no obvious chemical interactions are observed between them in the fibers prepared by mechanically mixing. In both cases, the CNTs have significantly strengthened the PAN fibers. However, the fibers prepared from in situ polymerization mixing are much stronger because of the interfacial bonding effect between the PAN molecules and CNTs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

碳纤维增强PA66复合材料新工艺的开发

传统工艺碳纤维增加PA66复合材料批次间有差异、产品理化性能不稳定、工艺能耗高,而本生产工艺工序简洁,能耗少,成本低,生产效率高。     

无机复合涂层对碳纤维性能的影响

采用溶胶-浸渍法在碳纤维表面制备了二氧化钛-二氧化硅复合涂层。考察了钛溶胶与硅溶胶体积比、浸渍方式、浸渍次数对涂层的影响。利用X射线衍射（XRD）、扫描电镜（SEM）和透射电镜（TEM）分析了涂层的相组成及形貌。通过静态等温氧化实验考察了复合涂层碳纤维的抗氧化性能。结果表明：钛溶胶与硅溶胶体积比为15∶1条件下采用真空超声浸渍3次,制备的复合涂层均匀、完整、致密,与碳纤维表面结合良好,涂层抗氧化性能好,涂层二氧化钛为锐钛矿型、二氧化硅为无定型。将复合涂层碳纤维在400 ℃连续氧化15 h,其质量损失率仅为5.91%。     

环氧/碳纤维复合材料性能研究

本文主要分析了碳纤维帘子布复合材料的性能,并与T300单向碳纤维复合材料性能进行对比。结果表明,碳纤维帘子布复合材料性能低于T300单向碳纤维复合材料性能。     

纳米镍／炭复合材料的制备研究

采用阳离子交换树脂作为炭载体的前驱体,经过镍离子交换,再经热解后制备了一种纳米镍／炭（n—Ni／C）复合材料。以XRD、SEM、TEM、EDS为主要分析手段研究了热解条件对纳米镍在n—Ni／C复合材料中的形貌、大小和分布情况的影响。结果表明：通过热解条件可以控制n—Ni／C复合材料中纳米镍的粒径;TEM和SEM—EDS观察表明热解所得n—Ni／C复合材料中的纳米镍颗粒大小均匀、分散性好。差热分析（DTA）研究结果表明加入n-Ni／C可增加高氯酸铵（AP）的表观放热量,降低AP的高温分解峰,最大可达95℃。     

Al2O3-SiC复相粉对Al2O3-SiC-C材料性能的影响

以电熔白刚玉(3～1、≤1、≤0.044 mm)、Al2O3-SiC复相粉(d50≤5μm)、α-Al2O3微粉(d50=1.2μm)、SiC粉(≤0.044 mm)、鳞片石墨(≤0.088 mm)、Si粉(d50=42.8μm)和B4C(d50≤10μm)为主要原料,热固酚醛树脂为结合剂,研究了分别用4%、8%、12%、16%质量分数的Al2O3-SiC复相粉等比例取代α-Al2O3微粉和SiC细粉对Al2O3-SiC-C试样在180℃固化后和1 000、1 500℃埋焦炭热处理后的显气孔率、体积密度、常温抗折强度、常温耐压强度、高温抗折强度(1 400℃)、抗热震性(1 100℃,水冷)以及抗氧化性(1 000、1 500℃)的影响。结果表明:随Al2O3-SiC复相粉加入量的增加,试样经180℃固化后常温性能下降,1 000℃热处理后常温性能变化不大,1 500℃热处理后除耐压强度显著提高外,其余各项常温性能变化不大;而高温抗折强度下降,抗热震性明显提高,试样经1 500℃氧化后的抗氧化性以加入4%质量分数复相粉的最佳。其原因可能是由于该复相粉的粒度更细,反应活性更高,其氧化层中更易生成莫来石,形成表面致密层从而有效地阻碍氧气向材料内部扩散。     

单体接枝改性炭黑填充NBR复合材料的研究

采用单体接枝改性法制备炭黑填充型NBR复合材料，并对其性能进行研究。结果表明，在NBR胶乳与炭黑的混合体系中加入适当的单体M[丙烯酸丁酯（BA）或甲基丙烯酸甲酯（MMA）]和引发剂，可以使单体M与NBR分子链发生接枝反应的同时也与炭黑表面的活性基团发生反应，从而制备NBR／M／炭黑复合材料；采用该方法制备的NBR／M／炭黑复合材料的炭黑分散性良好，物理性能和热稳定性优异。     

Interfacial structure and stability of a co-continuous SiC/Al composite prepared by vacuum-pressure infiltration

The interfacial structure of a SiC_3D/Al composite prepared by vacuum-pressure infiltration was investigated to determine whether interfacial reactions occur and specific orientation relationships exist between SiC and Al. The resulting SiC/Al interfaces were continuous and free of any precipitates and voids. There is no consensus for the orientation relationship between 6H-SiC and Al. In addition, the mismatch between the two phases at the interface was accommodated by mismatch dislocation. The stability of the SiC_3D/Al composite after annealing at 873 K for 10 h was determined. No Al₄C₃ precipitated at the interface, although grain coarsening of Al occurred. Compared with the concentration gradients at the initial interfaces, those obtained at the interface after annealing were still steep, indicating that concurrent interdiffusion occurred between SiC and Al in a very narrow region near the interfaces. Theoretical calculations suggest similarly the chemical and structural stability of the SiC/Al interface during the annealing treatment.