Performance experiment on preparation of composite SiO₂/EP wear-resistant coating through electrostatic spraying

To improve wear resistance of pure epoxy coatings on long-distance natural gas transmission pipelines, composite SiO₂/EP wear-resistant coatings are prepared by spraying SiO₂ ceramic powder on the surface of unconsolidated epoxy coatings. Impacts of SiO₂ contents, curing temperatures and heated curing time on bonding strength, hardness and wear resistance of composite coatings are studied by classification method, Vickers/micro hardness tester, erosion testing machine and SEM. Research results show that bonding strengths of SiO₂/EP composite coatings prepared through electrostatic spraying are equivalent to those of pure epoxy coatings. Given SiO₂ content of 30%, curing temperature of 60℃ and heated curing time of 30 min, optimal overall performances of composite coating are obtained. Hardness of the composite coating is 5 times of pure epoxy coating, and wear resistance is 4 times higher.