【作者】 曹银南；

【导师】 闵凡飞；

【作者基本信息】 安徽理工大学 ， 矿物加工工程， 2010， 硕士

【摘要】 颗粒增强铝合金基复合材料中研究最多的增强体有SiC、SiO2、Al2O3等颗粒,这些增强体一般都有尖锐的棱角,在受应力的作用下易引起应力集中,球形增强体以其优良的抗应力特性而得到广泛地关注。本文选择工业废弃物粉煤灰作为增强体,不仅提高铝合金复合材料性能,降低其成本,还能将粉煤灰变废为宝,达到以废治废的目的。课题首先通过酸溶法对粉煤灰进行表面改性,制得与铝合金基体相容性好的粉煤灰颗粒,然后采用粉未冶金法成功地制备了粉煤灰/Al合金复合材料,并对粉煤灰的最佳改性工艺及不同含量粉煤灰增强铝合金复合材料的制备工艺、密度、硬度、界面反应、微观结构、摩擦磨损性能及摩擦机理进行了研究。研究结果表明：(1)与盐酸和硝酸相比,硫酸改性粉煤灰效果最好,其最佳改性条件为浓度10mol/L硫酸溶液在常温下改性15h。(2)用粉末冶金法可以制备出密度较小、硬度较大的粉煤灰/A1合金复合材料。复合材料的密度随着粉煤灰质量分数的增加而减小,硬度先升高后减小,密度和硬度都随着烧结温度的升高而增大。(3)在不同烧结温度下,粉煤灰与铝合金基体均发生一定界面反应,生成有利于界面结合的MgO、MgAl2O4、Mg2Si等新生相。(4)复合材料的摩擦磨损性能均优于铝合金基体。复合材料的磨损量随着粉煤灰掺量的增加而减小,随载荷和磨损时间增大而增大；摩擦系数随粉煤灰掺量、载荷的增加先减小后趋于稳定然后增大,随摩擦磨损时间延长而增大。(5)粉煤灰／铝合金复合材料的主要磨损机制是粘着磨损、磨粒磨损,高载荷下出现剥层磨损。图34表4参75更多还原

【Abstract】 The most reinforcements studied in particle-reinforced aluminum alloy matrix composites are SiC, SiO2, Al2O3, etc. These reinforcements usually have sharp edges and corners and under the effect of stress in the subject could easily cause stress concentration, among of which spherical reinforcements for its excellent anti-stress properties receive extensive attention. The fly ash reinforcement of industrial waste not only improve the performance of aluminum composites and lower cost, but also with making full use of the fly ash waste circularly can turn fly ash waste into treasure. To obtain the fly-ash particles which have good compatibility with aluminum matrix composites, the paper first by acid-dissolution method carries out surface modification, then successfully prepares fly ash/Al alloy composite materials visa using powder metallurgy method and researches the best modification process of fly ash and the preparation process, density, hardness, interfacial reaction, microstructure, friction and wear properties and friction mechanism of reinforced aluminum alloy composites of different fly ash content. The results show that:(1) Comparing with hydrochloric acid and nitric acid, the effect of sulfuric acid-modified fly ash is the best, and the optimum conditions for modification is 10mol/L sulfuric acid solution at room temperature 15h.(2) A method of powder metallurgy can be prepared relatively small density and hardness greater composite materials. with the mass fraction of fly ash increasing, the density of composite decreases and the hardness value first increases and then decreases. As the sintering temperature increases, the density and hardness grows up.(3) At different sintering temperatures, fly ash and aluminum alloy matrix after interfacial reaction produces new substances, which are beneficial to interfacial bonding, MgO, MgAl2O4, Mg2Si and so on.(4) Friction and wear properties of composites are superior to aluminum alloy matrix. The wear volume of composites decreases with the fly ash increasing and increases accompanying that the load and wear time increases. The friction coefficient, with the increase in fly ash content and load, first decreases, then tends to stable and again decreases and the friction coefficient also decreases by extending the wear of time.(5) The main wear mechanism of fly ash/aluminum composite materials is adhesive wear, abrasive wear. The delamination wear occurs at high load.Figure 34 table 4 reference 75更多还原