Gas-phase aluminum-silicon diffusion agent used on complicated inner cavity blades, and application method thereof

The invention provides a gas-phase aluminum-silicon diffusion agent used on complicated inner cavity blades, and an application method thereof. The diffusion agent is composed of metal silicon powder, ferro-aluminum powder, and ammonium chloride powder. The particle size of the metal silicon powder is 200 to 400 meshes. The weight of the metal silicon powder takes 80 to 90% of the total weight of the metal silicon powder and the ferro-aluminum powder. The particle size of the ferro-aluminum powder is 200 to 400 meshes. The mass of iron takes 50 to 60% of the total mass of the ferro-aluminum powder. The weight of ammonium chloride takes 2 to 3% of the total weight of the metal silicon powder and the ferro-aluminum powder. The blades and the diffusion agent are positioned in a muffle tank with a required vacuum degree of 10Pa to 50Pa; the muffle tank is heated to a temperature of 900+-10 DEG C, and the temperature is maintained for 2 to 4 hours; air is blown by using a stirring blower, and the muffle tank is co