【作者】 刘晓新；

【导师】 赵新兵；

【作者基本信息】 浙江大学 ， 材料科学与工程， 2006， 硕士

【摘要】 爆轰法是大规模制备纳米石墨粉的一种较好的方法,石墨铝基复合材料因具有优异性能被广泛用作耐磨件和减震零件等。本文着重对纳米石墨（nmGr）的爆轰合成、特性及在铝基复合材料中的应用进行了研究,主要内容如下: 1) 对纳米石墨的制备方法及应用领域进行了综述; 2) 研究了不同的炸药密度、保护气氛种类及压力对纳米石墨得率的影响。不同的炸药密度下,纳米石墨的得率随密度的提高而增加:相对于Ar、N₂、He等保护气氛和低真空条件下,CO₂作为保护气氛时纳米石墨的得率较高;保护气氛的压力增至2atm时,相对较低保护气氛压力下的得率较高; 3) 爆轰法制备的纳米石墨粉是六方结构的,呈球形或类球形;X射线衍射分析、激光Raman分析、比表面积测试、透射电子显微分析均表明,纳米石墨的颗粒度为纳米级,表面含有C-H键、硝基、醛基、醌基等官能团; 4) 对石墨-铝基复合材料的研究现状进行了综述;探索纳米石墨-铝基复合材料的制备方法,结果表明热压可以得到较好的nmGr-铝合金复合材料烧结体,经过热挤压可以提高复合材料的密度:当纳米石墨添加量较低时（如1wt%）分散较好; 5) 加入纳米石墨的量在2wt%以下时,不会降低复合材料的拉伸性能;而加入同等质量百分比的微米级石墨时复合材料的拉伸性能略有降低; 6) Al-6.3Mg中加入纳米石墨可以显著地降低复合材料的摩擦系数及磨损率,纳米石墨的添加量在2wt%以下时,磨损率基本保持不变;加入纳米石墨可以降低Al-0.8Mg-1.4Si复合材料的摩擦系数,但磨损率随纳米石墨加入量增加而增加;6061Al配方的铝合金分别加入纳米和微米石墨后,当加入量为1wt%时石墨时,加入纳米石墨的复合材料磨损率较低,而当石墨的加入量为2wt%时,加入微米级石墨的磨损率较低;7)加入纳米石墨后,Al-0.8Mg-1.4Si合金的阻尼因子增加;对于6061Al配方的铝合金,加入纳米及微米石墨后阻尼因子均增加,但加入纳米石墨后的阻尼因子高于加入微米石墨后的阻尼因子,在高温阶段纳米石墨的作用更加显著。更多还原

【Abstract】 Detonation is a better way in preparing nanographite (nmGr) extensively. Gr-Al matrix composite materials are used in wear-resistant parts and damping of vibration parts because of their excellent characters. The detonation synthesis, characters and application in the Al matrix composite materials were researched chiefly in this paper. The main contents are follows:1) The preparation methods and application fields of nmGr were summarized;2) The influences of different explosion density, kinds and pressure of protection atmosphere on the yield of nmGr were researched. The yield of nmGr increases with the raise of density of explosion;the yield of nmGr is higher when the protection atmosphere is CO2 comparing to Ar, N2, He and low vacuum;When the pressure of the protection atmosphere adds to 2 atm, the yield of nmGr is higher;3) The structure of nmGr obtained from detonation is hexagonal. The pattern of nano graphite is sphere or sphere-like;X-ray diffraction microscopy, laser Raman analysis, specific surface analysis and transmission electron microscope analysis all indicate that the size of nano graphite’s is nanometer;The surface of the nano graphite contains C-H, -NO2, -HCOH, quinonyl etal atom groups;4) The research state of Gr-Al matrix composite materials was summarized;their preparation method was explored. The results indicate that through hot pressing can obtain better nmGr-Al matrix composite materials sinter. Hot pressing can increase the density of composite materials;when the weight percent of the nmGr is 1, the dispersion of the nano graphite is homogeneous;5) When the weight percent of nano graphite is not more than 2, the tensile strength of the composite materials is unable to decrease, but micron graphite (equal weight percent) can make the tensile strength of the composite materials decrease;6) The friction coefficient and loss of wear can decrease when the nmGr is added in the Al-6.3Mg composite materials. The friction coefficient can decrease obviously when the nano graphite is added in the Al-0.8Mg-l.4Si composite materials, bur the loss of wear increases with the increases of nmGr percentage;When the weight percent of the Gr added in the 6061A1 is 1, the loss of wear rate is lower when nmGr as additive, but when the weight percent of the Gr added in the 6061 Al is 2, the loss of wear is lower when μmGr as additive;7) The damping of Al-0.8Mg-Si alloys increases when the nmGr is added in them. For 6061 alloys, the nmGr and μmGr can all make the damping factors increase, but the damping factors of nmGr added in the composites are higher than μmGr added in the composites.更多还原