(1. 中南大學 粉末冶金國家重點實驗室，長沙 410083；2. 廈門航空有限公司，廈門 361006)
摘 要: 以炭纖維(Cf)針刺整體氈為預制體，分別采用化學氣相滲透 (Chemical vapor deposition, CVI)和浸漬炭化(Impregnation and carbonization, I/C)制備不同密度和基體炭的C/C坯體；通過添加Ti元素改善熔融Cu與C/C坯體的潤濕性。采用真空熔滲法制備C/C-Cu復合材料。對復合材料的力學性能及其與坯體之間的關系進行研究，并與常用滑板材料的力學性能進行比較。結果表明：隨著坯體密度的增加，復合材料的抗彎強度下降，而坯體密度為1.4 g/cm3的復合材料的沖擊韌性達到最大值。與用I/C坯體制備的復合材料相比，用CVI坯體制備的復合材料具有更高的強度和韌性，其彎曲曲線呈“假塑性”斷裂特征，斷裂時纖維從熱解炭層或熔滲金屬相中拔出，熔滲金屬相呈“韌窩狀”的塑性斷裂形貌。沖擊斷裂時，復合材料傾向于沿TiC/熔滲金屬界面斷裂。C/C-Cu復合材料的抗彎強度為180~300 MPa、沖擊韌性高于3.5 J/cm2，優(yōu)于常用滑動電接觸材料的性能，是一種極具潛力的新型滑動電接觸材料。
關鍵字: C/C-Cu復合材料；熔滲；力學性能；斷裂機制；滑動電接觸材料
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
