The invention provides a submicron crystalline
ceramic coating for a hard
alloy and a preparation method. The components of the submicron crystalline
ceramic coating comprise Al2O3, ZrO2, TiO2, and SiO2. The preparation method comprises the following steps: respectively weighing
powder materials, mixing the
powder materials, heating to smelt the mixture, carrying out water
quenching on the mixture to obtain non-crystalline
ceramic, and ball-milling to obtain non-crystalline ceramic
powder; adding Co powder into the non-crystalline ceramic powder, adding a
solvent, and wet-milling to obtain
coating slurry; coating the surface of the hard
alloy with the coating
slurry,
drying the hard
alloy, and
sintering the hard alloy in a vacuum environment to obtain the submicron crystalline
ceramic coating for the hard alloy. According to the invention, problems that the
sintering temperature of SAZ
ceramic coating is high, and the
thermal expansion coefficient is not matched with the hard alloy are solved, the prepared coating has the advantages of high-
temperature resistance and
corrosion resistance, the preparation method is simple, the production cost of the hard
alloy coating can be greatly reduced, such failure problems as oxidation,
corrosion and attrition of hard alloy components under actual working conditions are solved to a certain extent, and the service lives of hard alloy materials and devices are prolonged.