Mechanical behavior of unidirectional carbon fiber-reinforced polyamide 6 composites under transverse tension and the structure of polyamide 6 among carbon fibers

Abstract

The mechanical properties of unidirectional carbon fiber (CF)-reinforced polyamide 6 (PA6) composites subjected to transverse tension were studied in terms of the structure of the PA6 matrix among the CFs. Two types of CFs with different surface profiles (one smooth and one rough) were used as reinforcements in this study. The surface profile of the CFs had no effect on the tensile strength or Young’s modulus of the composites, whereas the surface profile influenced the strain at break of the composites. According to the results of X-ray diffraction analyses, the crystalline structure of the PA6 matrix in the composites was not substantially influenced by the type of CF. Polarized micrographs of the composites revealed that the birefringence of the PA6 matrix at the interface of the CFs with rough surfaces was remarkably higher than that of the matrix away from the fibers (i.e., in the bulk region). The difference in the local crystalline structure of the PA6 matrix among the CFs can affect the mechanical behavior of the unidirectional PA6/CF composites under transverse tension. The mechanical properties of a unidirectional carbon fiber (CF)-reinforced polyamide 6 (PA6) composite subjected to a tension perpendicular to the CFs was studied by using two types of CFs with different surface profile. The difference of local crystalline structure of PA6 among CFs can be affected to the mechanical behavior of unidirectional PA6/CF composite under transverse tension.