碳纤维增强聚甲醛复合材料的制备及性能研究

发布时间：2018-10-23 16:27

【摘要】：随着社会的不断进步,工业化的飞速发展,交通运输业越来越发挥其重要作用,同时对交通工具和动力机械的速度、负荷及安全性能要求越来越高,因此作为交通工具的摩擦材料其相应的要求也更高。摩擦材料不仅要具有良好的耐温性能、机械强度、耐磨性能及稳定的摩擦系数,还要具有质轻,制动时无噪音,对环境无污染,成本低等一系列特点。碳纤维具有良好的耐磨性、导热率高、抗拉性能好、对环境无污染、质轻等优点,在摩擦材料中发挥着举足轻重的作用。同时由于界面在复合材料中能够起到传递应力及各组分形成一个整体的作用,因此界面对复合材料综合性能的发挥起着关键性作用。研究结果表明,良好的界面结合强度有助于复合材料力学性能的发挥。本文首先研究了碳纤维增强树脂基复合材料的界面性能,采用丙酮、浓硝酸、硅烷偶联剂对碳纤维进行了四种不同性质的表面处理,并分别采用处理后的碳纤维制备了碳纤维树脂基复合材料。采用扫描电子显微镜(SEM)、微机控制万能试验机研究了碳纤维树脂基复合材料的拉伸强度与断口微观形貌的变化,结果表明：碳纤维经过丙酮浸泡,浓硝酸粗化,再经过硅烷偶联剂处理与碳纤维经过丙酮浸泡,浓硝酸处理增强了碳纤维与基体的结合强度。紧接着再研究碳纤维与铜颗粒对聚甲醛复合材料的摩擦磨损性能、硬度、冲击强度的影响规律。将不同含量的碳纤维、铜颗粒加入聚甲醛基体中制成了不同配比的复合材料,通过实验仪器测得摩擦系数、磨损率、硬度及冲击强度,并对磨损后的形貌及冲击断面进行观察。通过实验研究表明：碳纤维、铜颗粒显著提高了聚甲醛的耐磨性,0.628m/s,100N实验条件下,碳纤维100%+铜颗粒10%构成的复合材料的磨损率最低,其磨损率比单独添加碳纤维10%降低了48.5%。摩擦表面形貌分析表明,添加铜颗粒使复合材料摩擦表面光滑,但却增大了摩擦系数。不同含量的碳纤维和铜颗粒的加入会不同程度的增加摩擦材料的硬度。随着复合材料中碳纤维添加量的增加,其硬度值先增大后减小；当复合材料中碳纤维添加量为10%时,随着铜颗粒含量的增加,复合材料的硬度逐渐增大。随着复合材料中碳纤维添加量的增加,其冲击强度先增加后减小。当碳纤维含量为10%时,冲击强度随着铜颗粒含量增加而增加。添加铜颗粒的复合材料的冲击断面相对于不含铜颗粒的断面,出现断面不平整、凹凸不平的现象。
[Abstract]:With the continuous progress of the society and the rapid development of industrialization, the transportation industry is playing an important role more and more. At the same time, the speed, load and safety performance of the vehicles and power machinery are more and more demanding. Therefore, as a vehicle of friction material its corresponding requirements are higher. Friction materials should not only have good temperature resistance, mechanical strength, wear resistance and stable friction coefficient, but also have a series of characteristics such as light weight, no noise during braking, no pollution to environment, low cost and so on. Carbon fiber has the advantages of good wear resistance, high thermal conductivity, good tensile performance, no pollution to the environment, light weight and so on. It plays an important role in friction materials. At the same time, the interface plays a key role in the comprehensive properties of the composite because it can transfer the stress and form a whole function of each component in the composite material. The results show that the good interfacial bonding strength is helpful to the exertion of the mechanical properties of the composites. In this paper, the interfacial properties of carbon fiber reinforced resin matrix composites were studied. The surface of carbon fiber was treated with acetone, concentrated nitric acid and silane coupling agents. Carbon fiber resin matrix composites were prepared with treated carbon fibers. The change of tensile strength and fracture morphology of carbon fiber resin matrix composites was studied by scanning electron microscope (SEM),) microcomputer controlled universal testing machine. The results showed that carbon fiber was soaked in acetone and thickened by nitric acid. After silane coupling agent treatment and carbon fiber soaking in acetone, concentrated nitric acid treatment enhanced the bond strength between carbon fiber and matrix. Then the effects of carbon fiber and copper particles on the friction and wear properties, hardness and impact strength of POM composites were studied. The composites with different proportions were prepared by adding carbon fiber and copper particles with different contents into the polyformaldehyde matrix. The friction coefficient, wear rate, hardness and impact strength were measured by means of experimental instruments. The morphology and impact section of the composites after wear were observed. The experimental results show that the wear resistance of polyformaldehyde is significantly improved by carbon fiber and copper particles. Under the experimental condition of 0.628 m / s / s ~ 100N, the wear rate of composites composed of 10% carbon fiber 100% copper particles is the lowest, and the wear rate is 48.5% lower than that of 10% carbon fiber alone. The analysis of the friction surface morphology shows that the friction surface of the composites is smooth but the friction coefficient is increased with the addition of copper particles. Different content of carbon fiber and copper particles will increase the hardness of friction materials. With the increase of carbon fiber content, the hardness of the composite increases first and then decreases. When the carbon fiber content is 10%, the hardness of the composite increases with the increase of copper particle content. With the increase of carbon fiber content, the impact strength of composites increases first and then decreases. When the carbon fiber content is 10, the impact strength increases with the increase of copper particle content. Compared with those without copper particles, the impact section of the composite with copper particles is uneven and uneven.
【学位授予单位】：长春工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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