Characterization of the tensile behavior of continuous carbon fiber reinforced polyamide 6 under self‐resistance electrical heating

Abstract

The stamping molding with self‐resistance electric (SRE) heating is advantageous for the mass production of carbon fiber reinforced thermoplastic (CFRT) because of its short production cycle and energy efficiency. The mechanism of SRE heating is different from traditional oven heating. The impact on CFRT laminates under loading is ambiguous. In this article, the tensile testing systems with SRE heating and traditional heating were designed. The temperature distribution, mechanical response, strain, and failure mode of carbon fiber reinforced polyamide 6 (CFR‐PA6) laminates under SRE heating are studied and contrasted with traditional heating. Specifically, to measure the full‐field strain distribution, digital‐image correlation (DIC) technique and high‐speed camera were introduced. It is found that the electric resistance fluctuates in tensile test with SRE heating and shown temperature sensitivity. Temperature distribution of the specimen under SRE heating is relatively uniform. Besides, the mechanical properties (i.e., tensile strength and elastic modulus) of CFR‐PA6 seem to be insensitive to heating mode. DIC results show that deconsolidation phenomenon makes the specimen fracture randomly. Inversely, heating method has an obvious influence on failure modes. To be specific, there are more shearing damage in traditional heating during high temperature. High current under SRE heating causes corrosion on fiber surface and destroy the fiber‐resin matrix interface.