Interfacial shear strength of opaque resin/carbon fiber based on mapping from energy dispersive X‐ray spectroscopy

Abstract The interface between carbon fibers and resin has a great effect on the mechanical properties of composites, and acts as a bridge for the transportation of load between fibers and resin. The traditional measurement method for interfacial shear strength (IFSS) relies mainly on single‐fiber fragmentation test, which is not suited for opaque composites. In this article, a new method for measuring the interfacial shear strength of opaque resin/carbon fibers was firstly put forward. We used mapping from energy dispersive X‐ray spectroscopy (EDS) which replaced the polarizing microscope to detect the breakpoints of samples after being stretched. We found that the value of IFSS for composites made by carbon fibers and epoxy resin detected by traditional method and new method was similar, which indicated single‐fiber fragmentation test based on mapping from EDS was accurate. The value of IFSS for composites made by carbon fibers and epoxy resin modified by carbon nanotubes was measured by mapping from EDS, which indicated the wide applicability in opaque composites. The single‐fiber fragmentation test based on mapping from EDS made the IFSS measurement of opaque composite become possible, which made a great progress compared with traditional method.