Effect of graphene nanosheets on interlaminar mechanical properties of carbon fiber reinforced metal laminates

石墨烯纳米片对碳纤维增强金属层板层间力学性能的影响

¹ College of Aerospace Engineering, Shenyang Aerospace University, Shenyang 110136, China
² School of Mechanical Engineering, Northwestern Polytechnical University, Xi′an 710072, China
³ Shenyang Aircraft Design Institute, Shenyang 110035, China

Received: 3 June 2021

Abstract

Aiming at the problem of weak bond strength between CARALL metal/resin/fiber layers, this paper proposes a new preparation method to improve the bond strength between CARALL layers. In this method, Graphene platelets (GnPs) with different mass fractions (0%, 0.1%, 0.3%, 0.5% and 1.0%) are uniformly dispersed in epoxy resin by ultrasonic dispersion method, and using the wet layup method completes the production of CARALL. Carry out the I type fracture toughness test, explore the influence of GnPs on the CARALL interlaminar performance, and carry out the test of the tensile and flexural properties of CARALL to study the influence of GnPs on the mechanical properties of CARALL. The enhancement mechanism of GnPs and the failure mode of CARALL specimens were observed by SEM and optical images. The results show that when the amount of GnPs added is 0.5%, CARALL has the best interlaminar strength and mechanical properties. When 0.5% GnPs is added, the type I fracture toughness is increased by 79%; the tensile strength, Young's modulus, and strain rate at break are increased by 14.5%, 11.0%, and 15.5%, respectively; the flexural strength and flexural strain rate are increased by 20.5% and 89.7%, respectively. This is because adding GnPs to the epoxy resin can disperse the load carried by CARALL, and use its own fracture, pull-out and debonding mechanisms to absorb energy, and further improve the interlayer mechanical properties of CARALL.

摘要

提出一种新的方法, 用来改善碳纤维增强金属板(CARALL)的层间黏结强度。将不同质量分数(0, 0.1%, 0.3%, 0.5%和1.0%)的石墨烯纳米片(GnPs)利用超声分散的方法使其均匀分散于环氧树脂中, 并利用湿法铺层方法完成CARALL的制作。进行Ⅰ型断裂韧性的测试, 探究GnPs对CARALL层间性能的影响, 并进行CARALL的拉伸与弯曲性能测试, 研究GnPs对CARALL力学性能的影响。通过SEM与光学图像观察GnPs的增强机制与CARALL试件的失效模式。结果表明, 当GnPs的添加量为0.5%时, CARALL具有最佳的层间黏结强度与力学性能。当添加0.5%GnPs时, Ⅰ型断裂韧性提高79%;拉伸强度、弹性模量与断裂应变率分别提高14.5%, 11.0%和15.5%;弯曲强度与弯曲应变率分别提高23.9%和81.5%。这是由于添加GnPs到环氧树脂中可以分散CARALL所承受载荷, 并利用自身的断裂、拔出和脱黏等机制吸收能量, 进一步改善CARALL的层间力学性能。