CeF_3对无压熔渗法制备TiC/Ni_3Al复合材料的渗入工艺影响

Effect of CeF_3 on Manufacturing of TiC/Ni_3Al Composites by Using Pressureless Melt Infiltration Process

以化学纯镍粉、钛粉、铝粉、石墨粉为原料,采用燃烧合成方法置备了TiC/Ni3Al含孔预制件,用无压熔渗法制备了Ni3Al熔渗TiC/Ni3Al复合材料,研究了CeF3对无压渗透工艺、渗透动力学及TiC/Ni3Al复合材料的微观组织、硬度的影响。采用XRD和SEM分析了复合材料的相组成、微观结构。试验结果表明,无压熔渗法是制备致密的TiC/Ni3Al复合材料的有效方法,添加适量稀土CeF3,可大大缩短渗透时间;在完成渗透获得致密组织的前提下,添加CeF3对TiC/Ni3Al复合材料的硬度无显著影响;渗透后复合材料的组成相为Ni3Al和TiC两相,Ni3Al相和TiC颗粒结合良好;制备的TiC/Ni3Al复合材料的维氏硬度随TiC体积分数的增加而增加,w(CeF)3为0.6%,w(TiC)分别为70%和80%时,复合材料的维氏硬度平均值分别为HV561和HV653。

Porous TiC-Ni3Al was synthesized by SHS （self-propagating high-temperature synthesis） method by using nickel, titanium, aluminum and graphite powder of chemically pure reagent. Pressureless melt infiltration was used for preparing TiC/Ni3Al composites. Effects of CeF3 on the pressureless infiltration process, the infiltration kinetics and microstructure, hardness of the composites were studied. XRD and SEM were used to analyze the phase identification and the microstructure. The results show that pressureless melt infiltration is an effective method to fabricate dense TiC/Ni3Al composites. The infiltration time can be greatly decreased by adding suitably amount of CeF3. CeF3 has no obvious effect on the Vickers hardness of the composites. Ni3Al and TiC were well bonded, and they are the only two phases in the composites after infiltration. The Vickers hardness of TiC/Ni3Al composites was increased with increasing the amount of TiC. The Vickers hardness of TiC/Ni3Al composites was 561 and 653 when the mass percent of CeF3 was 0.6% and of TiC was 70% and 80%, respectively.