(1. 中南大学 粉末冶金国家重点实验室，长沙 410083；2. 厦门航空有限公司，厦门 361006)
摘 要: 以炭纤维(Cf)针刺整体毡为预制体，分别采用化学气相渗透 (Chemical vapor deposition, CVI)和浸渍炭化(Impregnation and carbonization, I/C)制备不同密度和基体炭的C/C坯体；通过添加Ti元素改善熔融Cu与C/C坯体的润湿性。采用真空熔渗法制备C/C-Cu复合材料。对复合材料的力学性能及其与坯体之间的关系进行研究，并与常用滑板材料的力学性能进行比较。结果表明：随着坯体密度的增加，复合材料的抗弯强度下降，而坯体密度为1.4 g/cm3的复合材料的冲击韧性达到最大值。与用I/C坯体制备的复合材料相比，用CVI坯体制备的复合材料具有更高的强度和韧性，其弯曲曲线呈“假塑性”断裂特征，断裂时纤维从热解炭层或熔渗金属相中拔出，熔渗金属相呈“韧窝状”的塑性断裂形貌。冲击断裂时，复合材料倾向于沿TiC/熔渗金属界面断裂。C/C-Cu复合材料的抗弯强度为180~300 MPa、冲击韧性高于3.5 J/cm2，优于常用滑动电接触材料的性能，是一种极具潜力的新型滑动电接触材料。
关键字: C/C-Cu复合材料；熔渗；力学性能；断裂机制；滑动电接触材料
molten infiltration method
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Xiamen Airlines Co., Ltd., Xiamen 361006, China）
Abstract:Using Ti addition to improve the wettability between the molten copper and C/C preforms, C/C-Cu composites were fabricated by infiltrating molten copper to C/C preforms with different densities and matrix carbon types, which were prepared by chemical vapor deposition(CVI) or resin impregnation and carbonization (I/C). The mechanical properties of the composites and the relationship between the properties and preforms were studied. The mechanical properties were compared with those of the widely used sliding electrical contact material. The results show that, with the increase of the preform density, flexural strength of the composite decreases, while the impact toughness of the composite reaches the maximum at preform density of 1.4 g/cm3. The flexural strength and impact toughness of the composite from CVI preform are higher than those from I/C preform. For the composite from CVI preform, the flexure fracture shows a lot of pull-out fibers from the matrix and the dimple morphology of typical ductile fracture in the infiltrated Cu, while the impact fracture is inclined to along the TiC/Cu(Ti) interface. The flexural strength and impact toughness of the C/C-Cu composites, which are 180−300 MPa and higher than 3.5 J/cm2, respectively, are better than those of widely used C/Cu sliding electric contact material, so the C/C-Cu composite is a new competitive sliding electrical contact material.
Key words: C/C-Cu composites; infiltration; mechanical properties; fracture mechanism; sliding electric contact material
