钛合金/碳纤维布复合材料的界面与力学性能的研究

An investigation on interface optimization and mechanical properties of Cu-coated carbon fiber cloth/titanium alloy composite

摘要:

本文选用Ti-6Al-4V钛合金为基体,镀铜碳纤维布为增强相来制备钛合金/碳纤维布复合材料。通过放电等离子烧结法(SPS)对镀铜碳纤维布与钛合金薄片进行叠层烧结,制备钛合金/碳纤维布叠层复合材料,并对其界面形貌、微观组织与力学性能进行表征。结果表明：镀铜碳纤维均匀分布在钛合金/碳纤维布复合材料中,CuTi, Cu和少量的TiC沿着纤维和基体的界面分布。钛合金/碳纤维布复合材料具有比钛合金略高的塑性,同时屈服强度和抗压强度与钛合金相比有了明显的提高。碳纤维表面电镀铜对复合材料界面有着重要的影响：(1)显着降低钛合金/碳纤维布复合材料的烧结温度；(2)提高了碳纤维和钛基体之间的润湿性,改善了界面结合,从而提高了钛合金/碳纤维布复合材料的力学性能；(3)有效地抑制TiC脆性相的产生,与未镀铜的碳纤布增强钛复合复合材料相比,镀铜碳纤维布/钛合金复合材料具有更好的塑性。

Abstract:

Using Cu-coated carbon fiber cloth (CFC) as reinforcement and Ti-6Al-4V (TC4) as matrix, the Cu-coated CFC/TC4 composite is fabricated by spark plasma sintering. The interface morphology, phase microstructure, phase distribution and mechanical properties of CFC/TC4 are characterized. Results show that carbon fibers are uniformly distributed in Cu-coated CFC/TC4. CuTi, Cu and very little TiC are distributed along the interface between fibers and matrix. Possessing slightly better plasticity than TC4, the yield strength and compressive strength of Cu-coated CFC/TC4 are obviously enhanced. The electroplated Cu plays important roles: (1) markedly decreases the sintering temperature of Cu-coated CFC/TC4; (2) significantly improves the wettability and interfacial bonding between carbon fibers and TC4 matrix, giving explanation to the increase of mechanical properties of Cu-coated CFC/TC4; (3) effectively inhibits the excessive generation of brittle TiC compared with uncoated CFC/TC4 composite, explaining the maintaining of good plasticity of Cu-coated CFC/TC4.