碳化还原法制备纳米碳化铬粉末.doc

2010届毕业生
毕业论文
题目: 碳化还原法制备纳米碳化铬粉末

院系名称:材料科学与工程专业班级: 材料F0605
学生姓名: 学号:
指导教师: 教师职称:
2010年5月30日
摘要
过渡金属碳化物具有较高的熔点、硬度和高温强度,这些材料同样显示良好的电导率和热导率。这些优异的性能确保了它们在冶金、电子、催化剂和高温涂层材料等方面的广泛应用。
现在,各种各样合成碳化铬粉末的方法已经被研究,包括直接元素反应法、机械合金化法、程序升温反应法和气相还原碳化法。但是,这些方法在工业应用中受到了限制,主要由于团聚问题、较宽的粒径分布、低产量、复杂的监控和昂贵的成本。
本实验课题采用纳米碳黑和纳米氧化铬为原料,用碳化还原法制造纳米铬,分别在不同的C含量(26%,28%),不同的烧成温度(900℃,1000℃,1100℃)和不同的保温时间(30min,60min,90min)下制造纳米碳化铬,并用金相显微镜,XRD,红外线谱检测生成物的性质。
通过实验得出以下结论:在C含量为28%,烧成温度为1100℃,保温时间为90min时,生成物不含其它杂质相,为单一的Cr3C2,纳米碳化铬的各种性质最趋近于理想值。
关键词:碳化铬,碳化还原法,纳米氧化物,XRD
Title:Preparation of nano carbon reduction chromium
carbide powder
Abstract
Transition metal carbides has a high melting point, hardness and high temperature strength, these materials also show good electrical conductivity and thermal conductivity. The excellent performance to ensure that their metallurgy, electronics, catalysts and high-temperature coating materials such as extensive use of
Now, the various chromium carbide powder synthesis methods have been studied, including direct element reaction, mechanical alloying, temperature-programmed reaction and carbonation gas reduction law. However, these methods in industrial applications has been limited, mainly due to reunion, a wide size distribution, low yield, complicated and expensive monitoring costs.
In this study, subjects using nano-carbon black and nano-chromium oxide as raw materials, manufacture nano-carbon chromium reduction method At different C content (26%, 28%), different sintering temperature (900 ℃, 1000 ℃, 1100 ℃) and different holding time (30min, 60min, 90min) of the manufacturing nano-chromium carbide, with metallographic microscopy, XRD, infrared spectral detection of resultant nature.
The experiment shows the following conclusions: the C content was 28%, sintering temperature is 1100 ℃, holding time was 90min, the resultant free of other impurity phase, various properties of chromium carbide nano the most close to ideal.
Keywords:Chromium carbi