竹炭/碳纤维增强树脂基摩擦材料摩擦磨损性能

采用腰果壳油改性酚醛树脂和丁腈橡胶为粘结剂,具有高弹性模量和高强度的碳纤维为增强纤维,竹炭、重晶石和蛭石等为填料,采用热压成型工艺制备树脂基摩擦材料,研究了竹炭含量对摩擦材料的剪切强度、密度和摩擦磨损性能的影响,借助扫描电镜观察磨损表面形貌并分析磨损机理。结果表明:随着竹炭含量的增加,材料的剪切强度和密度相应减少;添加竹炭能明显提升在250℃和350℃下的摩擦系数,对于100℃下的摩擦系数影响较小;增加竹炭含量,材料的磨损率逐渐变大,磨损机制由单一磨粒磨损向黏着磨损和磨粒磨损的复合磨损机制转变。     

金属/PES复合自润滑材料的制备及摩擦学性能研究

提出一种新金属/聚醚砜(PES)复合材料。用镶嵌、喷涂和机械共混-模压成型法制备了金属/PES复合自润滑材料。通过摩擦磨损实验对材料在干摩擦条件下的摩擦学性能进行了研究,考察载荷、转度对材料摩擦性能的影响;并用SEM对磨损表面进行了观察和分析,探讨了复合材料的磨损机制。结果表明,用镶嵌、喷涂和机械共混-模压成型法能制得摩擦学性能优良的复合材料;在干摩擦实验的载荷范围内,复合材料的摩擦因数和磨损量随转速的增加不断增大,随载荷的增加不断减小;复合材料的磨损机理发生了由犁削、磨粒磨损向黏着磨损的转变。     

纤维增强复合材料摩擦片的摩擦性能

研究FB树脂、YSM树脂和ALPF树脂基复合材料摩擦片的摩擦性能,结果表明:FB树脂基摩擦片性能最优.FB树脂的最佳成型温度在170℃左右,此时摩擦片有较大的摩擦因数和较小的磨损率.提高摩擦片的密度可以增大摩擦因数,降低磨损率.     

Elastic and Strength Properties of Thermoplasts Randomly Reinforced with Short Carbon Fibres

The linearity of the modulus of elasticity of a randomly reinforced composite as a function of the volume content of fibre filler is experimentally established. The basic factors that determine the modulus of elasticity of the thermoplastic composite are determined: the modulus of elasticity, shape, and volume content of filler. The modulus of elasticity of the composite is not a function of the adhesion of the fibre filler to the matrix. Realization of the strength of fibre fillers in randomly reinforced composites should obey the mechanisms that hold for unidirectional, continuously reinforced composites with consideration of the effect of the filler and process parameters on the rheology and morphology of the binder.     

PTFE填充PI基复合材料摩擦学性能

以聚四氟乙烯(PTFE)为填料,聚酰亚胺(PI)为基体,通过机械冷压法制备了聚酰亚胺/聚四氟乙烯(PI/PTFE)自润滑复合材料。研究了PTFE在复合材料中质量分数对该材料和金属试件对磨时摩擦学性能的影响。结果表明:在一定质量范围内PTFE的加入对于提高复合材料耐磨性具有积极的促进作用。当PTFE质量分数为30%时,PI/PTFE复合材料磨损率最低。和纯PI相比,填充PTFE的复合材料耐磨性提高3个数量级。对试件磨损形貌的分析表明:在对偶面形成转移膜的连续性直接影响PI/PTFE复合材料的摩擦磨损行为。对应最佳摩擦学性能时形成的自润滑转移膜更加连续、光滑和完整。     

Thermophysical Properties of Alumina Particle Reinforced Glass Matrix Composites

Alumina particles incorporated glass matrix composites, which showed good prospect to be used as coating materials for high‐temperature corrosion protection on intermetallics or titanium alloys, were prepared via pressureless sintering. With increasing alumina content, the Young's modulus, fracture strength, Vickers hardness, indentation toughness, softening point, and thermal shock resistance of the composites increased monotonically. A similar increasing trend could be found for the thermal expansion coefficient of the composites, except for an abnormal drop at small amount of incorporation, which closely correlated with the Al³⁺ dissolution into the glass matrix.     

Polymer Composite Materials Made from Carbon, Basalt, and Glass Fibres. Structure and Properties

Basalt plastics molded by polycondensation filling (intercalation of monomers) have better physicomechanical properties than fibreglass plastics and are much less expensive than carbon-fibre-reinforced plastics. Modifiers can be added to increase the properties of basalt plastics by 14-26%. The synthesis and hardening process parameters ensure almost total binding of phenol and formaldehyde in a cross-linked hybrid composite that satisfies safety standards and environmental requirements.     

苎麻纤维增强磷建筑石膏复合材料耐水性能和力学性能研究

通过吸水率、软化系数、抗折强度和抗压强度试验,并结合傅里叶红外光谱和扫描电子显微镜测试,探究不同长度和掺量的苎麻纤维对苎麻纤维增强磷建筑石膏复合材料耐水性能和力学性能的影响。研究结果表明,掺入适量苎麻纤维可改善苎麻纤维增强磷建筑石膏复合材料的耐水性能和力学性能,以及提高复合材料的延性。掺入0.5%(体积分数,下同)的10 mm苎麻纤维时,复合材料的软化系数达到最大,较空白组提高20.0%。苎麻纤维的掺入能有效提高复合材料的抗折强度,28 d时,掺入1.5%的10 mm苎麻纤维试样较空白组抗折强度提高39.5%。掺入小于20 mm的苎麻纤维会降低复合材料的抗压强度,掺入不超过1.5%的30 mm苎麻纤维可提高复合材料的抗压强度,28 d时,掺入1.5%的30 mm苎麻纤维试样较空白组抗压强度提高10.1%。苎麻纤维在复合材料基体内会发生水解,随龄期的增长水解程度加重,表面逐渐粗糙。     

混杂填料增强聚四氟乙烯复合材料的摩擦学性能研究

采用MM-200型摩擦磨损试验机对纳米SiC、MoS2和石墨填充聚四氟乙烯(PTFE)复合材料在干摩擦条件下与45#钢对摩时的摩擦磨损性能进行了研究,探讨了MoS2、石墨及纳米SiC的协同效应。认为纳米SiC的加入大大提高了复合材料的承载能力,石墨、MoS2的加入减少PTFE复合材料的摩擦因数。利用扫描电子显微镜(SEM)对PTFE复合材料的摩擦面进行了观察。结果表明:实验中5%nano-SiC和3%MoS2填充PTFE复合材料的摩擦磨损性能最好,且在高载荷下的摩擦磨损性能尤为突出,具有一定的应用价值。     

Heat-Resistant Coreless Silicon Carbide Fibres for Composite Materials with Ceramic and Metallic Matrices

An original method of synthesis of fibre-forming polycarbosilane was developed. A study of the physicochemical properties of samples of Japanese and our polycarbosilane demonstrated their identity. Manufacture of coreless silicon carbide fibres was investigated. The conditions were developed and samples of fibres with a strength of up to 2.5 and a modulus of elasticity of 180 GPa were made. It was found that the physicomechanical properties of our fibres are on the level of mass-produced Japanese fibres and their structural and thermal characteristics are identical. Translated fromKhimicheskie Volokna, No. 4, pp. 9–14, July–August, 2000.     

C/PyC/Si-C-N复合材料的热物理性能研究

本研究采用CVI方法制备出了以Si-C-N陶瓷为基体以热解碳为界面的碳纤维增强陶瓷基复合材料(C/PyC/Si-C-N).用热膨胀仪和激光导热仪分别测试了C/PyC/Si-C-N的热膨胀性能和热扩散性能.研究结果表明:在25～1200℃范围内,C/PyC/Si-C-N复合材料的平均热膨胀系数为0.638×106 K-1;而热扩散率则随温度的升高而减小,并与温度呈一种指数关系,常温下的热扩散率约为0.00925 cm2·s-1.     

Thermophysical Properties of Carbon-Carbon Materials Based on Graphite Foam

Refractories and Industrial Ceramics - Low density heat-conducting carbon-carbon materials containing coke from 2.8 to 40 wt.% and with density varying in the range from 0.065 to 0.81 g/cm3 are...     

Preparation and Properties of Reinforced Engineering Materials

Refractories and Industrial Ceramics - The literature on preparation methods and signature features of composites based on transition-metal carbides, nitrides, and borides; covalent compounds (SiC,...     

Thermal and Mechanical Properties of Flax Fibres as Potential Composite Reinforcement

Scutched and hackled long flax fibres varying in retting degree, namely green, under‐retted and normally retted flax, and elementary fibres were tested for their mechanical and thermal properties. Tensile tests were performed on individual fibres and on bundles. The thermal stability is evaluated with thermogravimetric analyses (TGA) and determination of the mechanical properties after thermal exposure. For the investigated samples, no significant influence of the retting degree on tensile strength can be determined. Exposure to different temperatures results in a weight decrease and affects the mechanical properties of the fibres.     

高性能纤维增强复合材料应用的研究进展

纤维增强复合材料具有质轻、高比强度和比模量、加工成型性好、耐冲击、耐腐蚀等特性,在轻量化材料领域有着广阔的发展前景,综合对比了玻璃纤维、碳纤维、芳纶及超高相对分子质量聚乙烯纤维等纤维增强复合材料在航空航天、汽车领域、能源工业、环保领域中的应用现状,认为碳纤维增强复合材料在轻量化、高性能化方面具有极大的优势及应用前景。     

纤维树脂基复合材料微观界面性能表征方法的进展

纤维树脂基复合材料中界面微观结构和性质对材料的宏观性能起着关键性作用。为了能够准确地测试纤维树脂间的界面粘结力,表征纤维与树脂之间界面剪切应力传递效率,人们一直试图找到一种方法能够真实全面反映界面性能,以及纤维断裂、界面脱粘、树脂横向断裂等因素对界面性能的影响。为此作者对现有微观界面表征方法进行介绍与分析,包括:微珠试验、单纤维拉出试验、压入试验、单纤维断裂试验、激光拉曼(或荧光)色谱法、光弹分析法,全面剖析它们的适用范围。