毕业论毕业论文文题题 目目: Cr-Al-C 系陶瓷体系设计及系陶瓷体系设计及 反应路径研究反应路径研究 摘摘 要要本研究主要对利用铬粉、铝粉和石墨三种单质为原料，采用热压法制备Cr2AlC 三元层状可加工陶瓷的体系和反应路径进行了研究，首先在氩气的保护下对原料进行了差热分析，并对在不同温度下烧结制备的材料进行了 X射线衍射分析，结合扫描电镜、能谱分析等先进仪器设备，研究了其物相组成和结构形貌。对 Cr2AlC 陶瓷的反应路径进行分析表明：以铬粉、铝粉和石墨为原料且原子量比 Cr：Al：C1：1.2：1 在 8501250热压烧结，并利用 X 衍射仪、电子探针和能量分散光谱进行反应路径分析。差热分析和 X 衍射分析表明 Cr2AlC的连续物相组成可在 CrAl 二元系统相图的基础上进行分析，并且发Cr9Al17、Cr5Al8和 Cr2Al 是在加热过程中产生的中间相化合物。Cr2AlC 的含量随Cr-Al 金属间化合物的反应温度的增加而增加，在 1050时样品的中间相主要为Cr2Al 金属间化合物，未参加反应的石墨在 1250以上随中间相的消失而成为样品中的残余相，Cr2AlC 成为主晶相，同时含有少量的 Cr7C3相。关键词： Cr2AlC 陶瓷 可加工陶瓷 金属间化合物 扫描电镜（SEM） Title system designing and phase formation sequence of Cr-Al-C ceramics AbstractThis study mainly to used the chromium powder, the aluminite powder and the graphite three kind of simple substances as raw material, system and the reaction way has been studied of Cr2AlC layered and possible processed ceramics,which prepared by hot- pressing process .First differential thermal analysis has been used under the argon protection to raw material.And X-ray diffraction(XRD) has been carried on the ceramics material which maked under the different temperature.At the same time, scanning electric microscope（SEM）and energy dispersive spectrum(EDX)were employed for identification of phase assembly and structure appearance.The reaction process of Cr2AlC ceramics was analyzed,in which the samples were prepared for composition Cr:Al:C=1:1.2:1 by hot-pressing in argon in the range of 8501450 using Cr,Al and graphite powders as the starting materials.X-ray diffraction(XRD), scanning electric microscope (SEM)and energy dispersive spectrum(EDX)were employed for identification of phase assembly and analysis of reaction route of the samples.The phase formation sequence of Cr2AlC was finally analyzed based on phase diagram of the CrAl binary system combined with the results of differential thermal analysis(DTA)and X-ray diffraction(XRD).It was found that Cr9Al17、Cr5Al8 and Cr2Al were the intermediate phases appearing in turn in the heating process.The amount of Cr2AlC phase was gradually increased with increase in temperature by the reaction between CrAl intermetallic compounds,un-reacted Cr and graphite,and it became the most phase with little Cr7C3 in the sample with disappearance of intermediate phases above 1250.Keywords: Cr2AlCceramics; machinable ceramics; Intermetallic compounds; scanning electric microscope（SEM）目目 次次1 引言.1 1.1 陶瓷.1 1.2 现代陶瓷.1 1.3 三元层状可加工陶瓷.2 1.4 制备 Cr2AlC 陶瓷的理论基础.2 1.5 Cr2AlC 陶瓷的性能和结构特征.3 1.6 Cr2AlC 陶瓷的应用及发展前景.4 1.7 本研究内容及意义.4 2 材料制备及研究方法.5 2.1 原材料及其观察.5 2.1.1 原料配比设计.5 2.2 试验材料制备.6 2.2.1 原始粉末混合制备.6 2.2.2 Cr2AlC 粉体的制备.7 2.3 热压制备 Cr2AlC 块体材料.7 2.3.1 热压烧结原理.7 2.3.3 实验过程及设备.8 2.3.3 热压制备 Cr2AlC 块体材料流程图.82.3.4 热压制备 Cr2AlC 块体材料的烧成制度.9 2.4 材料分析测试.9 2.4.1 热分析.9 2.4.2 X-射线衍射分析 .10 2.4.3 扫描电镜（SEM）和能谱分析（EDX）.10 3 试验结果和讨论.