浸渍-涂覆型BN界面相对化学气相渗透法制备SiC_f/SiC复合材料力学性能的影响(英文)

以硼酸和尿素为先驱体,采用浸渍-涂覆法在氮气气氛中在SiC纤维表面制备BN界面相。利用SEM/EDS、XRD和FT-IR对BN界面相的形貌和结构进行表征。采用化学气相渗透法(CVI)制备SiCf/SiC复合材料,并研究BN界面相对复合材料力学性能的影响。结果表明:光滑的BN界面相覆盖在SiC纤维表面,厚度约为0.4μm,为紊乱层状的t-BN物相。有无BN界面相的复合材料弯曲强度分别为180和95 MPa,并且有BN界面相的复合材料表现出明显的韧性断裂行为。微观结构分析表明,BN界面相在基体渗透过程中保护纤维免受化学腐蚀,减弱纤维和基体之间的界面结合强度方面发挥重要作用,这有助于大幅度提高复合材料的力学性能。     

颗粒增强金属基复合材料界面微观结构和性能研究进展

界面作为颗粒增强金属基复合材料中硬质颗粒和金属基体之间连接的“纽带”,直接影响复合材料的力学和摩擦性能,为了更好地揭示界面特性与复合材料整体性能之间的耦合关系,需要对界面展开微观研究。综述近年来对颗粒增强金属基复合材料界面的研究进展。主要分为三个方面：界面结构显微表征,即通过一系列电子显微镜和能谱分析,得到界面形貌、反应产物以及取向关系等信息;微观力学性能测试,即表征界面在微观尺度下的形变和失效过程,进而得到结合强度、断裂韧性等信息;模拟计算,在常规试验达不到的尺度,分析界面的结合能、电荷分布和电子结构,以及模拟界面的变形和失效过程。界面的微观研究对于界面改性和进一步提高颗粒增强金属基复合材料性能具有一定的指导意义。     

碳纤维表面处理对Cf/SiO2复合材料力学性能的影响

对T-300碳纤维进行表面改性处理,并采用浆料浸渍-热压法制备了单向碳纤维补强石英基复合材料(Cf/SiO2).对改性前后碳纤维的表面形貌、官能团的变化以及复合材料的力学性能和断面形貌进行了研究.结果表明,T-300碳纤维经过硝酸氧化处理后,去除了表面的有机胶料层,含氮、氧的官能团数量增加,有利于改善成型时纤维和浆料之间的润湿性能.复合材料的抗弯强度由处理前的433 MPa提高到了655 MPa,断裂韧性也从9.1 MPa·m1/2提高到12.9MPa·m1/2.在热压烧结的过程中,碳纤维表面有机胶料发生热解形成的气态物质难以排出,在纤维/基体界面上形成了孔洞,影响了界面结合状态,不利于载荷的传递.因此,对碳纤维进行表面改性有效地提高了复合材料的力学性能.     

复合材料腐蚀机理研究的一些进展

本文简要介绍了近年来国内外对树脂基复合材料的腐蚀机理以及某些方面的研究进展。主要论述了复合材料的树脂基体、纤维及树脂/纤维界面对材料耐腐蚀性能的影响,同时也涉及到腐蚀介质在复合材料中的扩散、外应力对复合材料腐蚀过程的影响等问题。     

热辐射处理制备VC涂层的盐雾腐蚀性能

采用热辐射处理在Cr12MoV基体上制备了VC涂层,通过盐雾腐蚀试验研究了VC涂层腐蚀性能,并讨论了其抗盐雾腐蚀机理。用SEM表征了VC涂层表面-界面形貌和腐蚀形貌,用EDS分析了化学元素组成。结果表明,VC涂层为整体结构,由V-C的多相构成,涂层与基体界面为冶金结合+机械结合方式;涂层的腐蚀形式主要为点腐蚀+化学腐蚀,腐蚀后表面出现裂纹,但裂纹未穿透至基体,涂层对基体具有很好的保护作用。     

铝基复合材料的腐蚀与防护研究现状

对Cf/Al、SiC/Al、Al2O3/Al三种铝基复合材料的腐蚀研究现状和防护方法进行了讨论.Cf/Al复合材料以电偶腐蚀为主.SiC/Al 复合材料的腐蚀多发生在碳化硅纤维和铝基体的界面处,其原因是界面处的缝隙容易导致孔蚀和缝隙腐蚀,并最终可能造成表面剥层.Al2O3是绝缘体,与Al不存在电偶腐蚀,同SiC/Al和C/Al等相比具有更高的耐腐蚀性.目前提高铝基复合材料的防腐蚀性能的方法,主要包括铝基复合材料表面阳极氧化防护膜、表面化学钝化防护膜、其他表面涂镀层、增强体表面涂层、基体合金化等.最后展望铝基复合材料腐蚀与防护的研究和发展.     

PBO纤维表面改性处理的研究进展

聚对苯撑苯并二噁唑(PBO)纤维因其比强度高、比模量高、耐热性好、阻燃性好以及优异的介电性能,现已在安全防护、建筑汽车等领域得到广泛应用。由于PBO纤维表面光滑、化学惰性,导致其与基体树脂界面结合差,进一步影响复合材料的整体性能,这大大限制了PBO纤维优异综合性能的发挥,所以对PBO纤维表面进行改性处理显得尤为重要。介绍了近年来国内外针对PBO纤维不同表面改性方法及对应复合材料性能改善程度的研究进展,从PBO纤维改性方法的分类入手,阐述了各种方法的基本原理。通过对这些处理方法的比较,阐述了国内PBO纤维表面改性的研究进展,指出了国内外在PBO纤维表面改性处理上的差距,为未来的发展方向提供了参考。PBO纤维表面改性方法包括化学刻蚀法、等离子体处理、表面涂层法、化学接枝法、紫外刻蚀法、上浆剂处理等。各种改性技术各有利弊,在选择改性方法时,理应考虑达到工艺快捷有效、经济环保和无损纤维性能等指标。未来,在PBO纤维表面改性的处理方法领域,将逐步向绿色环保的上浆剂处理方向发展。     

工业纯钛在硫酸中的腐蚀行为及其机理研究

研究了工业纯钛在硫酸溶液中的腐蚀行为及表面形貌演变，利用扫描电镜、粗糙度仪、能谱分析仪和X射线衍射分析仪对蚀刻前后的表面形貌、粗糙度、成分及物相组成进行分析，利用电子背散射衍射仪及透射电镜对纯钛基体的织构和显微组织进行表征。结果表明，工业纯钛的表面酸蚀处理可看作微电池腐蚀过程，具体分为3个阶段：钛氧化膜去除、钛基体溶解以及钛表层形成氢化钛吸气层。钛晶粒的取向差异导致蚀刻后钛表面形成具有取向性的多孔形貌，钛基体内析出的纳米粒子使蚀刻后的钛表面形成丰富的多孔结构。     

镍铝青铜化学镀镍磷合金和性能

以船用铜合金镍铝青铜为基体,采用酸性化学镀溶液体系制备镍磷合金镀层,对该镍磷镀层的界面结合情况及其强度、表面形貌、化学成分组成、硬度、耐海水腐蚀性能等进行了研究。结果显示,镀层为高磷非晶镀层,组织均匀致密,无孔隙等明显缺陷,界面结合强度高,同时硬度较高(646 HV),耐海水腐蚀性能明显优化。可见采用化学镀镍磷合金对镍铝青铜进行表面改性处理,可有效提高其综合性能,保护基体材料,延长其在海水中的服役寿命。     

耐海洋环境中霉菌腐蚀有机涂层的研究

为了提高铝合金耐海洋环境中霉菌腐蚀的性能,先在铝合金表面涂覆硅烷膜作为过渡层,然后在硅烷膜上涂覆成分配比不同的有机硅改性环氧树脂涂料.对比研究了涂层的表面形貌、相组成及霉菌腐蚀的性能.并探讨了涂层与基体的结合机理.结果表明:硅烷膜与铝合金基体、有机涂层之间发生了化学反应,使涂层与铝合金基体结合良好;按有机硅改性环氧树脂...     

The analysis of Armos fibers reinforced poly(phthalazinone ether sulfone ketone) composite surfaces after oxygen plasma treatment

The effects of oxygen plasma treatment on both the fiber surface and interfacial adhesion of Armos fiber reinforced PPESK composites were investigated in this paper. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were used to analyze fiber surface chemical composition and surface roughness, respectively. The results indicated that oxygen plasma treatment had introduced a large amount of reactive functional groups onto the fiber surface and the fiber surface roughness was increased largely. The interlaminar shear strength (ILSS) of the untreated and oxygen plasma-treated composites was measured to evaluate the interfacial adhesion. The values of ILSS were enhanced dramatically; the water molecule diffusion into composite along interface was prevented effectively. The composite fracture mode was observed by scanning electron microscopy (SEM), which showed that the primary failure mode varied from interface failure to matrix failure after oxygen plasma treatment. Results indicated that oxygen plasma treatment was an effective method to improve the interfacial adhesion properties of Armos fiber reinforced PPESK composites by both chemical bonding and physical effects.     

SiC纤维表面去碳处理对PIP-SiCf/SiC复合材料力学性能以及界面影响

采用强度测试、SEM、HRTEM等分析测试手段对纤维表面去碳前后SiC纤维强度、复合材料力学性能、纤维表面形貌、复合材料断口形貌以及复合材料界面特征进行分析表征.结果表明,去碳处理后,纤维表面的固有缺陷暴露出来,纤维强度下降约15%,但由其制备的复合材料强度下降只有原纤维制备复合材料的1/6;复合材料断口非常平整,纤维...     

复合材料用碳纤维等离子体表面改性技术进展

近年来复合材料得到了广泛的应用,尤其在航空工业领域,已成为了世界强国竞相发展的核心技术。碳纤维树脂基复合材料作为复合材料中的优秀代表,由于其独特的性能优势,具有很大的发展潜力,但是界面结合强度是制约其应用的关键瓶颈。等离子体表面改性技术能提高碳纤维与树脂基的界面结合强度。总结了国内外学者工作,从等离子体处理装备发展和工艺参数影响两个角度对碳纤维等离子体表面改性技术的研究进展进行了阐述。在装备发展方面,重点介绍了在碳纤维表面处理研究中三类处理装置,包括射频等离子体处理装置、DBD等离子体处理装置和滑动弧射流等离子体处理装置,分析了各自的优缺点。在工艺参数方面,重点介绍了不同等离子体种类、等离子体处理时间、等离子体放电功率对碳纤维表面状态的影响规律。在此基础上,对碳纤维等离子体表面处理技术的未来发展方向进行了展望。     

Influence of aging behavior of Armos fiber after oxygen plasma treatment on its composite interfacial properties

This work concerns the aging behavior of Armos fiber and Armos fiber reinforced poly (phthalazinone ether sulfone ketone) (PPESK) composite after oxygen plasma treatment. Armos fiber surface chemical composition, surface morphology and roughness, and surface wettability as a function of storage time in air after oxygen plasma treatment were measured by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and dynamic contact angle analysis (DCAA) system, respectively. The fiber surface aging behavior could be detected obviously in chemical composition and surface wettability, whereas the surface morphology and roughness remained nearly stable after storing in air as long as 10 days after oxygen plasma treatment. The effects of surface aging behavior after oxygen plasma treatment on Armos fiber reinforced PPESK composite interfacial properties were evaluated by interlaminar shear strength (ILSS) test and humid resistance measurement. It was found that the values of ILSS reduced and the composite humid resistance properties decayed. The polar functional groups that were reoriented from the surface into the bulk of the fibers or moved away from the fiber surfaces, maybe responsible for the weak interfacial strength between the fiber and the matrix in composite system.     

A model for predicting micromechanical interfacial adhesion in polymer composites

The mechanical behavior of fiber-reinforced composites is largely determined by adhesion at the fiber-matrix interface. Thus, a fundamental understanding of the interfacial region and a quantitative characterization of the level of interfacial adhesion can contribute to an evaluation of the mechanical behavior and performance of composite materials. Among numerous techniques for interface characterization, the vibration damping method has attracted continually more attention because it provides sensitive and nondestructive detection of the interfacial region in composites. In the research presented here, a new optical system for measuring vibration damping was introduced, and a model for evaluating the interfacial adhesion between fiber and matrix from a damping parameter was developed. A quantitative relationship between the dynamic (vibration damping) and static (interfacial shear strength) adhesion measurements was established. The experimental data from glass-fiber-reinforced epoxy resin composites with different interfacial treatments showed good agreement with the theoretical model.     

Research on Properties of Carbon Fiber/Epoxy Resin Composite Material by Microwave Curing

Microwave irradiation was used to reduce the curing time of carbon fiber/epoxy resin composite material.The properties of carbon fiber/epoxy resin composite material under microwave curing were investigated by thermogravimetry(TG),dynamic mechanical analysis(DMA),impact strength test and scanning electron microscope(SEM).The results show that composite materials patch have high thermal stability after microwave curing.The initial degradation temperature is 330.9℃,the maximum thermal decomposition rate is at 368.1℃.When the layer of composite materials patchis 4 layers,the dynamic mechanical properties are the best after microwave curing.The initial storage modulus is 43.2 GPa,increased 28.3 GPa and 27.1 GPa than 3 layers and 5 layers,the glass transition temperature(Tg)is 67.48℃,increased about 12 ℃than 3 layers and 5 layers.Microwave curing can significantly improve the infiltration capacity of epoxy resin,enhance interfacial bonding,and increase the impact strength of composite patch.Under microwave curing,the impact strength of 3,4,5-layers composite material patches increases 35.9%,6.4% and 15.1%,respectively than heating curing.The SEM analysis of impact fracture surface shows that microwave curing can improve the interface of carbon fiber and epoxy resin.     

碳纤维复合贴片的界面行为研究

采用低温等离子体法对碳纤维进行表面处理,并在微波固化条件下将碳纤维与环氧树脂复合成形,制得碳纤维复合贴片.采用X射线光电子能谱仪对碳纤维表面的元素组成进行了表征,采用扫描电镜和能量散射光谱(EDS)对碳纤维/树脂界面区的形貌和元素分布进行了表征.结果表明:碳纤维经处理后,其表面氨基官能团的含量增大,有利于纤维与树脂的化...     

橡胶/类金刚石复合材料界面结合及摩擦性能研究进展

综述了橡胶表面沉积DLC薄膜的主要制备技术,包括磁控溅射法和等离子体化学气相沉积法。概括了橡胶/DLC复合材料的表面形貌特性,尤其是温差对表面斑块结构的影响机制。重点介绍了X切割法、划痕法及拉伸法为主的橡胶/DLC复合材料界面结合力的评估方法,分析了基体表面等离子体处理、添加过渡层及异质元素掺杂DLC薄膜对提升橡胶与DLC薄膜结合力的影响。此外,以刚性球为摩擦配副,阐述了橡胶/DLC复合材料的摩擦性能测试方法。基于橡胶的黏弹特性,探讨了橡胶/DLC复合材料的摩擦行为,并归纳了Maxwell模型、Voigt模型、双Voigt模型和SLS模型的特点和局限性。最后,围绕目前橡胶表面DLC薄膜耐磨改性工作中存在的问题和挑战,探讨和展望了未来的研究方向。     

Macroscopic Mechanical Characterization of SMAs Fiber-Reinforced Hybrid Composite Under Uniaxial Loading

This paper presents an experimental and theoretical investigation on the macroscopic mechanical behavior of shape memory alloys (SMAs) fiber-reinforced glass/resin composite subject to uniaxial loading at ambient temperature. A series of unidirectional SMAs reinforced composite laminates is fabricated through vacuum-assisted resin injection. Scanning electron microscopy is conducted to evaluate the interfacial cohesive quality between SMAs fiber and matrix. A theoretical model is proposed based on the SMAs phase transformation model and rule of mixture. Uniaxial tensile tests are performed to study the effects of weak interface and SMAs fiber volume fraction on the effective modulus of composite. Failure morphology of composite is discussed based on the observation using digital HF microscope. Due to the effects of phase transformation and weak interface, the overall stiffness of SMAs composite at the second stage is on average 10% lower than theoretical results. The rupture elongation of experimental result is approximately 13% higher than theoretical result. The local interfacial debonding between SMAs fiber and glass/resin matrix is the main failure mode.