原位合成TiC_x增强Ni基复合材料及性能研究
发布时间：2018-07-28 07:37
【摘要】：颗粒增强镍基复合材料具有各向同性,易于成型,成本低廉,应用范围广等优点,采用原位合成法制备TiC_x增强Ni基复合材料具有粒子与基体结合牢固,孔隙率小,无明显杂质等优点,已成为当前研究的热点。本文基于改善颗粒增强镍基复合材料的强韧性、耐磨性和抗氧化性的目的,以Ti_3SiC_2为先驱体材料,利用Ti_3SiC_2陶瓷容易发生拓扑反应的特点,采用固态扩散方法原位合成TiC_x增强Ni基复合材料。研究TiC_x/Ni复合材料的微观组织、力学性能、耐磨性和抗氧化性能,并进一步探讨其失效机理。研究结果表明:(1)研究高温下Ti_3SiC_2陶瓷和金属Ni反应:在1200℃时,Ti_3SiC_2陶瓷和金属Ni界面结合良好,界面生成两层反应层,但是在此条件下无法合成复合材料。在1300℃时,通过扩散反应生成复合材料,研究了Ti_3SiC_2陶瓷和金属Ni体积比不同时的显微结构。结果表明:当Ti_3SiC_2和Ni体积比为2:1时,复合材料以TiC_x、Ni16Ti6Si7三元相和Ni31Si12等Ni-Si化合物为主要相,含有少量Ni(Si)固溶体;当Ti_3SiC_2和Ni体积比为1:1时,由于拓扑反应,Ti_3SiC_2完全转变成TiC_x,原位合成TiC_x颗粒增强Ni(Si)复合材料,并没有其它杂质相生成。(2)原位合成TiC_x增强Ni基复合材料的硬度值为663HV,弯曲强度为1234.30MPa±306.5 MPa;弯曲模量为147.629 kN·mm-2±19.28 kN·mm-2。利用扫描电镜对样品的三点弯曲断口形貌进行观察,发现这种复合材料的断裂形式主要是以韧性断裂为主,并伴随有少量的脆性断裂断口形貌。(3)研究了原位合成TiC_x增强Ni基复合材料在不同载荷作用下的滑动摩擦磨损性能。在室温下,这种复合材料的磨损失重和质量磨损率随载荷的升高而不断增加,但增加的幅度都不大。且随着载荷的增加,磨损表面上粘着和塑性变形的迹象逐渐加重。(4)研究了原位合成TiC_x增强Ni基复合材料在700、800、900℃下恒温氧化性能。在高温下,这种复合材料恒温持续氧化20 h,氧化动力学曲线基本符合抛物线规律,在700、800和900℃的氧化速率常数分别为1.51×10-4、7.07×10-4和4.52×10-3mg2·cm-4·min-1,氧化反应的活化能为188.56 kJ·mol-1。试样的氧化产物主要为TiO2,伴随有少量的NiO和SiO2。
[Abstract]:Particle reinforced nickel matrix composites have the advantages of isotropy, easy forming, low cost and wide application. The TiC_x reinforced Ni matrix composites prepared by in-situ synthesis method have the advantages of solid particle and matrix bonding and low porosity. No obvious impurity and other advantages, has become the focus of current research. In order to improve the strength, toughness, wear resistance and oxidation resistance of particle reinforced nickel matrix composites, Ti_3SiC_2 was used as precursor material and Ti_3SiC_2 ceramics were used to easily produce topological reactions. TiC_x reinforced Ni matrix composites were synthesized in situ by solid diffusion method. The microstructure, mechanical properties, wear resistance and oxidation resistance of TiC_x/Ni composites were studied. The results show that: (1) the reaction between Ti_3SiC_2 ceramics and Ni at high temperature is studied. The interface of Ti3SiC2 ceramics and Ni is well bonded at 1200 鈩，
本文编号：2149378
[Abstract]:Particle reinforced nickel matrix composites have the advantages of isotropy, easy forming, low cost and wide application. The TiC_x reinforced Ni matrix composites prepared by in-situ synthesis method have the advantages of solid particle and matrix bonding and low porosity. No obvious impurity and other advantages, has become the focus of current research. In order to improve the strength, toughness, wear resistance and oxidation resistance of particle reinforced nickel matrix composites, Ti_3SiC_2 was used as precursor material and Ti_3SiC_2 ceramics were used to easily produce topological reactions. TiC_x reinforced Ni matrix composites were synthesized in situ by solid diffusion method. The microstructure, mechanical properties, wear resistance and oxidation resistance of TiC_x/Ni composites were studied. The results show that: (1) the reaction between Ti_3SiC_2 ceramics and Ni at high temperature is studied. The interface of Ti3SiC2 ceramics and Ni is well bonded at 1200 鈩，
本文编号：2149378
本文链接：https://www.wllwen.com/kejilunwen/cailiaohuaxuelunwen/2149378.html
