CFRP层间碳纳米管定向喷涂工艺及断裂韧性研究

Interlaminar aligned carbon nanotubes spraying process and fracture toughness of CFRP

为了提高碳纤维增强树脂基复合材料(CFRP)层间性能,采用共沉淀法在碳纳米管上接枝磁性Fe_(3)O_(4)粒子,通过定向喷涂工艺使磁性碳纳米管(Fe_(3)O_(4)-MWCNTs)在碳纤维表面取向一致,并喷涂树脂加以固定,形成碳纤维-定向碳纳米管-树脂界面,采用真空辅助树脂渗透成形(Vacuum assisted resin infusion, VARI)工艺制备层间性能优异的Fe_(3)O_(4)-MWCNTs层间定向增强CFRP。试验结果表明,喷涂树脂可改善和巩固定向喷涂工艺。与未加磁场喷涂工艺相比,当Fe_(3)O_(4)-MWCNTs的质量分数为0.3wt%时,采用定向喷涂工艺试件的I型层间断裂韧性(GIC)提升幅度最大,GIC提高了37.7%。断面形貌分析表明其增强机制以树脂的塑性变形、Fe_(3)O_(4)-MWCNTs棒状聚集体的拔出及树脂塑性孔洞的生长为主。该研究为具有可控定向行为的磁性碳纳米管改性CFRP层间力学性能提供了新思路与方法。

Co-precipitation method was applied for grafting magnetic Fe_(3)O_(4) particles on carbon nanotubes. In order to improve the interlayer properties of carbon fiber reinforced polymer(CFRP), the magnetic carbon nanotubes(Fe_(3)O_(4)-MWCNTs) were aligned on the surface of carbon fiber by spraying process after exposure to magnetic field to form ‘carbon fiber-aligned carbon nanotubes-resin’ interface, and were fixed by spraying the resin. Aligned Fe_(3)O_(4)-MWCNTs-reinforced CFRP with excellent interlaminar properties was prepared by vacuum assisted resin infusion(VARI) molding. The test results show spraying resin plays an important role in consolidating and improving aligned spraying process. Compared with non-magnetic spraying process, when the mass fraction of Fe_(3)O_(4)-MWCNTs is 0.3 wt%, the mode I interlaminar fracture toughness(GIC) increases by up to 37.7%. The main toughening mechanisms, which are pull-out and rupture of Fe_(3)O_(4)-MWCNTs aggregates, plastic deformation and plastic void growth of resin, are revealed by the fracture surface morphology. The research provides a new idea and method for interface modification of CFRP by adding Fe3 O4-MWCNTs with controlled aligned behavior.