MECHANICAL PROPERTIES OF POLYAMIDE/CARBON-FIBER-FABRIC COMPOSITES

This paper presents the production of carbon-fiber-fabric-reinforced laminated composites based on a polyamide 6 matrix using a multiple-stages technique that involves polymer dissolution in formic acid followed by fabric impregnation and high-temperature pressing. The polyamide/solvent ratio's influence on the interface and mechanical properties is discussed, analyzing three PA6 weight contents of (10, 20, and 30) % in a formic acid solvent. The mechanical behavior of the obtained laminated composites is evaluated using tensile and 3-point bending tests and the fracture cross-section is analyzed using microscopy investigation techniques in order to evaluate the fiber-matrix interface and the composite fracture mechanism. The results show that the best mechanical performance is obtained when using a solution of 20 % mass fraction of polyamide in formic acid, as this leads to the formation of a uniform polymer layer that is able to completely embed the fibers that constitute the fabric and create a strong mechanical interface within the composite.