(中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 通过铺展实验研究添加Ti对NiAl金属间化合物与C/C复合材料润湿性的影响，发现添加Ti元素可改善熔融NiAl与C/C复合材料基体的润湿性。以低密度C/C复合材料为坯体，采用真空熔渗法制备C/C-NiAl复合材料，利用X射线衍射(XRD)和扫描电镜(SEM)对材料进行分析。结果表明：添加的Ti粉含量(质量分数)为15%时，C/C复合材料熔渗NiAl金属间化合物的效果最佳，且TiC颗粒与NiAl熔体在C/C复合材料内部呈网状分布；渗NiAl后材料的密度从1.35 g/cm3提高到2.47 g/cm3，开孔率从27%下降到15.1%，沿平行纤维排布面方向的洛氏硬度较未渗NiAl的C/C复合材料提高约30.7%。添加Ti能改善C/C复合材料渗NiAl性能的主要原因是Ti与C反应形成的TiC改善了NiAl在C/C复合材料中的化学吸附和物理吸附特性。
关键字: C/C复合材料；NiAl金属间化合物；钛；熔渗；润湿性
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The influence of adding titanium on the wettability of molten NiAl intermetallic on the surface of C/C composites was investigated by spreading experiment. It is indicated that adding Ti can improve the wettability between C/C composites and NiAl intermetallic. Using the low-density C/C composite perform the C/C-NiAl composites were prepared by the vacuum molten infiltration. The composites were analyzed by X-ray diffraction(XRD) and scanning electronic microscope(SEM). The results show that NiAl with about 15%Ti (mass fraction) possesses good wettability on the surface of C/C composites. The TiC particles and NiAl melt present network distribution in C/C composites internal. The density increases from 1.35 g/cm3 to 2.47 g/cm3 while the porosity decreases from 27% to 15.1% after the infiltration of NiAl. On the other hand, the Rockwell hardness of C/C-NiAl composites increases by 30.7% in the direction parallel to fiber fabric plane compared with that of C/C composites. The improvement of adding Ti for molten NiAl infiltration into the C/C composites results from the improvement of the chemical and physical adsorption characteristics of NiAl alloy on the composites, which is caused by TiC from reaction of Ti and C.
Key words: C/C composites; NiAl intermetallic; Ti; infiltration; wettability
