Effect of layer thickness of prepreg and fiber/matrix interfacial properties on impact resistance of carbon fiber reinforced polyamide 6

Abstract

In this study, quasi-isotropic (QI) laminates were fabricated using two types of PA6/CF thin-ply prepregs with different fiber/matrix interfacial properties, and Charpy impact tests and falling weight impact tests were conducted. The effects of layer thickness of prepreg and interfacial properties on the impact energy absorption performance were investigated by clarifying the fracture mode and propagation during impact. The layer thickness of each ply was set to 40, 80 and 120 μm by using thin-ply prepreg with the thickness of about 40 μm made by tow-spreading technology. Charpy impact values were higher for PA6/CFsmooth, where interface fracture was dominant, the values significantly increased as the layer thickness of the prepreg increased. On the other hand, the Charpy impact values of PA6/CFrough, where cohesive fracture is dominant, did not change significantly with increasing prepreg layer thickness. The results of the drop-weight impact test indicate that the layer thickness of the prepregs changing the fracture mode depends on the fiber/matrix interfacial properties. It is clear that the layer thickness at which the "thin-ply effect = reduced delamination" induced by changes in the layer thickness constituting the QI material is affected by the fiber/matrix interfacial properties. From the viewpoint of impact energy absorption, similar to the results of the Charpy impact test, it was shown that more impact energy can be absorbed when large scale delamination occurred.

Keywords

• cfrtp
• thin-ply prepreg
• quasi-isotropic
• layer thickness
• impact properties
• interfacial properties