Effects of thermal histories on interfacial properties of carbon fiber/polyamide 6 composites: Thickness, modulus, adhesion and shear strength

• Published in: Composites. Part A, Applied science and manufacturing Vol. 85; pp. 31 - 39
• Main Authors: Li, Hongfu, Wang, Yang, Zhang, Chenwei, Zhang, Boming
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2016
• Subjects: A. Thermoplastic resin; Annealing; B. Adhesion; B. Interface/interphase; Carbon fiber reinforced plastics; D. Mechanical testing; Droplets; Fibers; Interfacial shear strength; Polyamide resins; Polymer matrix composites; Thickness; D. Mechanical testing; B. Interface/interphase; A. Thermoplastic resin; B. Adhesion
• ISSN: 1359-835X; 1878-5840
• DOI: 10.1016/j.compositesa.2016.03.007

Interface thickness and modulus of carbon fiber (CF) reinforced polyamide 6 (PA 6) composites with different thermal histories are characterized as 331–394nm and 0.24–0.30 times to fiber modulus, respectively. Transverse fiber bundle (TFB) test is firstly employed for evaluating semi-crystalline PA 6 interfacial adhesion. TFB Failure mechanisms are schematically given. Besides enhanced molecular entangling on fiber surface, increased matrix toughness is also found to have a great effect on improved TFB results. Droplet micro-debonding results show that decreasing cooling rate and increasing annealing temperature both decrease interfacial shear strength (IFSS) though residual PA 6 on carbon fiber surface increases. In the end, the above data are normalized together with some previous measured parameters. It shows that quenching of the CF/PA 6 composites and subsequent annealing are shown to give similar results as slow cooling. Relationships between each other are also discussed.