▎ 摘　　要

NOVELTY - Preparing corrosion-resistant composite coating involves dehydrating the polycaprolactone polyol at 100-110 degrees C for 2 hours, then adding hexamethylene diisocyanate, mixing the mixture in an atmosphere furnace with nitrogen protection, heating to 100 degrees C at a heating rate of 5-10 degrees C, and keeping the temperature for 3-5 hours, at last cooling to normal temperature with the furnace to obtain coating component A, where the mass ratio of the polycaprolactone polyol to the A component is 20-40 wt.%, the mass ratio of the hexamethylene diisocyanate to the component A is 60-80 wt.%. The 4, 4-methylene-bis (2, 6-diethyl aniline), terminal amino polyether, and functional auxiliary agent are added into the beaker to mix uniformly, and processed for 2 hours to 3 hours at 60-90 degrees C to obtain coating component B, where 4, 4-methylene-bis (2, 6-diethyl aniline) occupying mass ratio of component B is 47-55 wt.%. USE - Method for preparing corrosion-resistant composite coating for vortex crushing cavity of sand making machine. ADVANTAGE - When the sand-making machine stops working, the composite coating on the surface also has the function of anti-corrosion, protecting the sand-making machine vortex crushing cavity will not be damaged by the residual with corrosive water to the vortex crushing cavity main body of erosion. DETAILED DESCRIPTION - Preparing corrosion-resistant composite coating for vortex crushing cavity of sand making machine involves dehydrating the polycaprolactone polyol at 100-110 degrees C for 2 hours, then adding hexamethylene diisocyanate, mixing the mixture in an atmosphere furnace with nitrogen protection, heating to 100 degrees C at a heating rate of 5-10 degrees C, and keeping the temperature for 3-5 hours, at last cooling to normal temperature with the furnace to obtain coating component A, where the mass ratio of the polycaprolactone polyol to the A component is 20-40 wt.%, the mass ratio of the hexamethylene diisocyanate to the component A is 60-80 wt.%. The 4, 4-methylene-bis (2, 6-diethyl aniline), terminal amino polyether, and functional auxiliary agent are added into the beaker to mix uniformly, and processed for 2 hours to 3 hours at 60-90 degrees C to obtain coating component B, where 4, 4-methylene-bis (2, 6-diethyl aniline) occupying mass ratio of component B is 47-55 wt.%, the mass ratio of the amino terminated polyether to the component B is 40-45 wt.%, the mass ratio of the functional auxiliary agent to the component B is 2-3 wt.%. The tea polyphenol powder is added into the round bottom flask filled with distilled water to obtain tea polyphenol solution, at the same time, the graphene oxide is added into the beaker containing distilled water, ultrasonically processed for 10-40 minutes, then the graphene oxide solution is slowly added into the tea polyphenol solution in stirring, and hydrothermal reaction is performed for 4-8 hours at 75-102 degrees C, the sample is taken out after finishing the reaction, and the centrifugal treatment is performed in the centrifuge with 6000-10000 revolutions per minute (r/min) of rotating speed, finally dried the obtained sample in the oven at 60-80 degrees C to obtain coating component C, where the mass ratio of the tea polyphenol powder to the component C is 60-80 wt.%, the mass ratio of the graphene oxide to the component C is 20-30 wt.%. The prepared component C is added into the component B and dispersed uniformly, a component BC mixture is formed, then the component A and component BC mixture, respectively are placed in high temperature and high pressure spraying machine, the temperature is set to be 60-70 degrees C, the spraying flow is set to 2000-2300 kilograms/minute (kg/min), then sprayed on the surface of the vortex crushing cavity of the sand making machine according to the volume ratio of 1:1, after solidifying, the corrosion-resistant composite coating is obtained, where the mass ratio of A: B: C in the corrosion-resistant composite coating is (40-60 wt.%):(30-45 wt.%):(1-10 wt.%).