原位自生TiN_x颗粒增强Cu基复合材料的制备及性能研究

发布时间：2018-06-20 09:41

  本文选题：Ti_2AlN + TiN_x　； 参考：《北京交通大学》2017年硕士论文

【摘要】：针对目前Cu基复合材料应用中高屈服强度高延展性的性能需求,本论文以Ti_2AlN陶瓷作为先驱体材料原位制备TiN_x颗粒增强Cu基复合材料,并研究了制备该体系材料存在的相关技术和科学问题。本文利用高温下Ti_2AlN陶瓷与Cu的反应行为,采用热压烧结法原位制备了TiN_x颗粒增强Cu基复合材料,通过X射线衍射(XRD)、扫描电镜(SEM)、能谱分析(EDS)等手段研究了不同工艺下制备的复合材料的相组成及微观结构变化,测试了其力学性能,并初步探讨了复合材料显微结构与性能之间的关系。研究结果表明:(1)在以Ti粉、A1粉和TiN粉为原料粉制备Ti_2AlN粉体时,原料粉三者的比例会对Ti_2AlN烧结纯度产生一定的影响。在氩气条件下,三者以1:1:0.95的比例在15℃/min的升温速率下升温至1450℃后保温0.5h烧结出的Ti_2AlN粉体纯度最高。(2)研究Ti_2AlN与Cu的反应行为发现,在1150℃,Ti_2AlN颗粒分解生成了TiN_x颗粒,而Al则进入基体Cu中形成Cu(Al)固溶体,TiN_x与Cu(Al)基体形成强结合界面。(3)以Ti_2AlN和Cu为原料在1150℃反应烧结制备的TiN_x/Cu复合材料,微米尺度的Ti_2AlN颗粒分解为亚微米和纳米级TiN_x颗粒,较均匀地分布于基体中。当Ti_2AlN的体积含量为10%～40%时,复合材料中几乎不存在Ti_2AlN,完全分解为TiN_x。(4)保温时间和初始体积含量对TiN_x/Cu复合材料的显微结构有一定的影响。当Ti_2AlN体积含量为30%时,TiN_x增强相颗粒的分布会随保温时间的增加而更加均匀地分布在基体内。相同保温时间下,TiN_x增强相颗粒随着初始Ti_2AlN含量的增加而逐渐增多。(5)热压烧结制备的TiN_x/Cu复合材料具有良好的力学性能。对于初始Ti_2AlN体积含量为30%的TiN_x/Cu复合材料,保温时间从0.5h增加至2h后,其抗压强度和压缩变形率分别从1060MPa和24.93%增加到1332MPa和38.68%;而抗弯强度从 630MPa 增加到了 785MPa。(6)随着初始Ti_2AlN体积含量的增加,复合材料的密度降低,电阻率、维氏硬度、压缩屈服强度和断裂韧性增加。当初始Ti_2AlN体积含量从10%增加到40%时,TiN_x/Cu复合材料的密度从8.25g/cm~3减小到7.31g/cm~3,维氏硬度从1.03GPa增加到3.03GPa,压缩屈服强度从150MPa增加到625MPa,断裂韧性由8.08MPa·m~(1/2)增加到 15.80MPa·m~(1/2)。
[Abstract]:In order to meet the requirement of high yield strength and ductility of Cu matrix composites, Ti2AlN ceramics were used as precursor materials to prepare TiNx particle reinforced Cu matrix composites in situ. The related technical and scientific problems in the preparation of the system were also studied. Based on the reaction behavior of Ti2AlN ceramics with Cu at high temperature, TiNx particle reinforced Cu matrix composites were prepared by hot pressing sintering in situ. The phase composition and microstructure of the composites prepared by different processes were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS), and the mechanical properties of the composites were tested. The relationship between microstructure and properties of composites was also discussed. The results show that when Ti powder Al powder and tin powder are used as raw materials to prepare Ti2AlN powder, the ratio of raw material powder to Ti2AlN powder will influence the sintering purity of Ti2AlN to some extent. In argon condition, Ti2AlN powders sintered at 15 鈩，

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