SEM Observation of Fracture Processes in Short Glass Fiber Reinforced Thermoplastic Composite
SourceTo study the fracture mechanism of a short glass fiber reinforced thermoplastic composite, the surface of the composite under stress was examined by a scanning electron microscope. The fracture processes, including crack initiation and propagation, could be observed in situ. The fracture was proved to proceed through five stages: (1) occurrence of a cluster of microcracks and voids in the matrix located at the fiber ends; (2) propagation of the interfacial microcracks in the matrix located on the fiber sides; (3) occurrence of bands of microcracks in the matrix, accompanied by the formation of shear bands in the matrix; (4) crack openings and slow crack propagation in the shear bands, followed by yielding and necking; and (5) catastrophic crack propagation, leading to the failure of the composite.