含能纳米铝粉的制备与性能

发布时间：2018-01-24 01:19

本文关键词： 纳米铝粉直流电弧氢等离子体法碳包覆工艺参数　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：为了提高火炸药和固体推进剂的能量性能,常采用添加金属粉的方法来实现。纳米金属粉相比于普通金属粉有着独特的优势,由于纳米铝粉具有高活性、高热值、后燃效应强等优势,所以向火炸药和固体推进剂中加入的纳米金属粉主要是纳米铝粉。然而,纳米铝粉的高活性使得纳米铝粉极易被氧化而失去活性,因此需要对纳米铝粉的表面进行改性,其中,在纳米铝粉的表面包覆碳层是行之有效的办法。本文分别采用直流电弧氢等离子体法和化学法制备碳包覆纳米铝颗粒。利用直流电弧氢等离子体法在1.0KPa CH4和2.5KPa Ar的气氛下制备的纳米铝颗粒,其XRD和HRTEM表明,部分纳米铝颗粒有碳包覆,部分纳米铝颗粒表面是A1203；通过TG-DTA分析,可以看出所制备的纳米铝颗粒氧化温度降低。而分别在0.5KPa CH4和2.5KPa Ar 2.0KPa CH4和2.5KPa Ar气氛下制备的纳米铝颗粒,其XRD分析中分别有很多Al2O3、Al4C3的衍射峰,这代表分别形成了大量的AL2O3、Al4C3等杂质。利用化学法制备碳包覆纳米铝颗粒,用红外碳硫分析仪、XRD、TEM、BET、Raman、TG-DTA等表征方法进行分析。实验结果表明,制备的纳米粉体碳含量为0.37%；内核铝的表面包覆层没有晶体结构且不同于钝化纳米铝粉表面的包覆层；制备的纳米粉体比表面积为5.967m2·g1计算得到的粒径为373.8nm,结合TEM照片说明纳米铝粉活性很高,极易发生团聚形成二次粒子；在拉曼位移为1601cm-’处,出现碳的G峰,与之对应的是纳米晶石墨。综上所述,利用化学法所制备的碳包覆纳米铝粉,表面包覆物是纳米晶石墨和氧化铝。通过对化学法所制备的碳包覆纳米铝颗粒与钝化处理的纳米铝颗粒进行TG-DTA测试,结果表明,制备的碳包覆纳米铝颗粒抗氧化性和稳定性明显提高。纳米铝粉的粒径决定其活性,是最基本,也是最重要的性能指标。为了能够利用直流电弧氢等离子体法批量制备粒径合适的纳米铝粉,探索了阴极电流、惰性气体压力等工艺参数对纳米铝粉产率和粒径的影响并分析了影响机理。结果表明,利用直流电弧氢等离子体法制备纳米铝粉,阴极电流和惰性气体的压力对纳米铝粉的粒径和产率影响很大；纳米铝粉的产率随着阴极电流的升高而增大,而纳米铝粉的粒径随着阴极电流的升高先增大后减小；在氢气和氩气的气氛中,随着惰性气体比例的升高,纳米铝粉的产率和粒径都会呈现先增大后减小的趋势。
[Abstract]:In order to improve the energy performance of explosives and solid propellants, metal powder is often added to achieve. Compared with ordinary metal powder, nano-metal powder has a unique advantage, because nano-aluminum powder has high activity. Because of the advantages of high calorific value and strong post-combustion effect, nano-aluminum powder is mainly added to the explosive and solid propellant. However, the high activity of nano-aluminum powder makes it easy to be oxidized and lose its activity. Therefore, it is necessary to modify the surface of nano-aluminum powder. It is an effective method to coat carbon layer on the surface of nano-aluminum powder. In this paper, carbon coated nano-aluminum particles were prepared by direct current arc hydrogen plasma method and chemical method, respectively. DC arc hydrogen plasma method was used at 1.0KP. A. Nanocrystalline aluminum particles were prepared in the atmosphere of CH4 and 2.5 KPA ar. The results of XRD and HRTEM showed that some of the aluminum nanoparticles were covered with carbon, while some of the aluminum nanoparticles had A1203 surface. By TG-DTA analysis. It can be seen that the oxidation temperature of the prepared nano-Al particles is lower than that of the prepared Al particles, and the oxidation temperature is decreased at 0.5KPa CH4 and 2.5KPa ar 2.0KPa CH4 and 2.5KPa, respectively. Nanocrystalline aluminum particles prepared in ar atmosphere. There are many diffraction peaks of Al _ 2O _ 3 and Al _ 4C _ 3 in the XRD analysis, which means that a large number of Al _ 2O _ 3-Al _ 4C _ 3 impurities were formed respectively. Carbon coated nano-aluminum particles were prepared by chemical method. The results showed that the carbon content of the prepared nano-powder was 0.37. The surface coating layer of the inner core aluminum has no crystal structure and is different from the coating layer on the surface of passivated nanometer aluminum powder. The specific surface area of the prepared nano-powder is 5.967m2 路g1. The calculated particle size is 373.8nm. the results of TEM show that the nano-Al powder has high activity and is easy to agglomerate to form secondary particles. At the Raman shift of 1601cm-', there is a G peak of carbon, corresponding to nano-crystalline graphite. In summary, carbon coated nano-aluminum powder was prepared by chemical method. The surface coating materials were nano-crystalline graphite and alumina. The results showed that the carbon coated nano-aluminum particles and passivated nano-aluminum particles were tested by TG-DTA. The oxidation resistance and stability of carbon coated nano-aluminum particles were improved obviously. The particle size of nano-aluminum powder determined its activity, which was the most basic. It is also the most important performance index. In order to be able to use DC arc hydrogen plasma method batch preparation of the appropriate size of nano-aluminum powder, the cathodic current has been explored. The effect of process parameters such as inert gas pressure on the yield and particle size of nanocrystalline aluminum powder was analyzed. The results showed that nanocrystalline aluminum powder was prepared by DC arc hydrogen plasma method. The cathodic current and the pressure of inert gas have great influence on the particle size and yield of nano-aluminum powder. The yield of nanometer aluminum powder increases with the increase of cathode current, while the particle size of nanometer aluminum powder increases first and then decreases with the increase of cathode current. In the atmosphere of hydrogen and argon, with the increase of the ratio of inert gas, the yield and particle size of nano-aluminum powder increase first and then decrease.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;TQ133.1

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