Preparation process and application of K444 high-temperature alloy turbine blade inner cavity cobalt-aluminum coating

The invention discloses a preparation process and application of a K444 high-temperature alloy turbine blade inner cavity cobalt-aluminum coating, and belongs to the technical field of high-temperature protective coatings. According to the process, the cobalt-aluminum coating is prepared in an inner cavity of the blade through a powder vapor infiltration method, a cobalt-aluminum powder infiltration agent is adopted in the powder vapor infiltration method, and the cobalt-aluminum powder infiltration agent is prepared from, by weight, 2-6% of aluminum powder, 1-6% of cobalt powder, 0.5-3% of ammonium chloride, 40-70% of aluminum oxide I and 25-45% of aluminum oxide II. The cobalt-aluminum coating prepared through the technology is low in cost, the method is simple and high in operability, accurate control over the components and the thickness of the coating can be achieved, and the hot corrosion performance of an inner cavity of the K444 high-temperature alloy turbine blade can be improved by coating the coati