Preparation and its cavitation performance of nickel foam/epoxy/SiC co-continuous composites

Co-continuous composites are a new class of composites with a unique topological structure. In this study, nickel foam/epoxy/SiC co-continuous composites were designed and prepared through a vacuum infusion process to improve the service life of materials used for corrosive erosion conditions. Optical microscope and scanning electron microscopy coupled with energy-dispersive spectrometry were used to characterize the morphology and element distribution of the composites. The impact strength of these composites was evaluated according to GB1943-2007. Their cavitation performance was studied with an ultrasonic cavitation tester in 0.1 M HCl aqueous solution, 0.1 M NaOH aqueous solution and deionized water. Results indicated that the epoxy mixture completely filled the void space of the nickel foam, the resin and metal compactly combined with each other and SiC reinforcement increased the impact strength of the composites. The cavitation experiment demonstrated that maximum weight loss occurred in the acid medium. Three sources of damage were found: the preferential failure of the metal phase because of mechanical action, chemical action and their synergetic effect; the brittle failure of the resin phase resulting from the cavitation loading; and a large quantity of peeled-off resins induced by the interface effect. Porous metal can effectively prevent crack expansion in the resin phase.