Currently, many methods are used to improve the fracture toughness of graphite/epoxy composites. However, no work has been done on the prepreg treatment with Ar+ ion irradiation. In the present work, the effect of surface treatment of prepreg by Ar+ ion irradiation on the delamination resistance of unidirectional graphite/epoxy laminated compositeswas studied. The surface of the prepregwas treated with Ar+ ion irradiation under oxygen environment, and the change of contact angle with surface-treatment was measured. Two kinds of [06//06] DCB (double cantilever beam) specimens were made: (1) DCB specimens made of graphite/epoxy prepregs that had been surface-treated with Ar+ ion irradiation under oxygen environment (Laminate A) and (2) DCBspecimens made of regular, untreated graphite/epoxy prepregs (Laminate B). The delamination resistance curve of Laminate A was compared with that of Laminate B so that the effect of prepreg treatment on the resistance behavior could be determined.
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